diff --git a/.eslintrc.json b/.eslintrc.json
index 565748a3..80a4f000 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -1,16 +1,17 @@
 {
-  "extends": "eslint:recommended",
   "env": {
     "browser": true,
     "es6": true,
-    "node": true,
-    "mocha": true
+    "mocha": true,
+    "node": true
   },
+  "extends": "eslint:recommended",
   "parserOptions": {
     "ecmaVersion": 8
   },
   "rules": {
-    "strict": 2,
+    "consistent-return": "off",
+    "func-name-matching": "off",
     "indent": ["error", 2, {
       "SwitchCase": 1,
       "CallExpression": {
@@ -18,28 +19,37 @@
       },
       "ArrayExpression": "off"
     }],
+    "handle-callback-err": "off",
     "linebreak-style": ["error", "unix"],
-    "quotes": ["error", "single"],
-    "semi": ["error", "always"],
-    "no-console": 0,
+    "no-buffer-constructor": "error",
+    "no-console": "off",
+    "no-cond-assign": "off",
+    "no-extra-semi": "off",
+    "no-fallthrough": "off",
+    "no-func-assign": "off",
+    "no-param-reassign": "off",
+    "no-shadow-restricted-names": "error",
+    "no-tabs": "error",
     "no-unused-vars": ["error", {
       "vars": "all",
       "args": "none",
       "ignoreRestSiblings": false
     }],
-    "no-func-assign": 0,
-    "no-cond-assign": 0,
-    "no-unreachable": 0,
-    "no-fallthrough": 0,
-    "no-useless-escape": 0,
-    "no-unsafe-finally": 0,
-    "no-extra-semi": 0,
-    "handle-callback-err": 0,
-    "no-buffer-constructor": 2,
-    "no-tabs": 2,
+    "no-use-before-define": ["error", {
+      "functions": false,
+      "classes": false
+    }],
+    "no-unreachable": "off",
+    "no-useless-escape": "off",
+    "no-unsafe-finally": "off",
+    "no-var": "error",
     "prefer-const": ["error", {
       "destructuring": "all",
       "ignoreReadBeforeAssign": true
-    }]
+    }],
+    "quotes": ["error", "single"],
+    "semi": ["error", "always"],
+    "strict": "error",
+    "valid-jsdoc": "error"
   }
 }
diff --git a/bench/tx.js b/bench/tx.js
index 07614609..af9db303 100644
--- a/bench/tx.js
+++ b/bench/tx.js
@@ -19,6 +19,7 @@ const btx = { tx: block.txs[397], view: new CoinView() };
 const tx3 = parseTX('../test/data/tx3.hex');
 const hex = fs.readFileSync(`${__dirname}/../test/data/wtx.hex`, 'utf8');
 const raw = Buffer.from(hex.trim(), 'hex');
+const tx = TX.fromRaw(raw);
 
 {
   const tx = json.txs[397];
@@ -153,25 +154,25 @@ for (let i = 0; i < 100; i++) {
   });
 }
 
-const tx = mtx.toTX();
+const tx2 = mtx.toTX();
 
 {
   const end = bench('input hashes');
   for (let i = 0; i < 1000; i++)
-    tx.getInputHashes(null, 'hex');
+    tx2.getInputHashes(null, 'hex');
   end(1000);
 }
 
 {
   const end = bench('output hashes');
   for (let i = 0; i < 1000; i++)
-    tx.getOutputHashes('hex');
+    tx2.getOutputHashes('hex');
   end(1000);
 }
 
 {
   const end = bench('all hashes');
   for (let i = 0; i < 1000; i++)
-    tx.getHashes(null, 'hex');
+    tx2.getHashes(null, 'hex');
   end(1000);
 }
diff --git a/bench/walletdb.js b/bench/walletdb.js
index 9a134a62..226024c8 100644
--- a/bench/walletdb.js
+++ b/bench/walletdb.js
@@ -24,6 +24,7 @@ const walletdb = new WalletDB({
 
   const wallet = await walletdb.create();
   const addrs = [];
+  let tx;
 
   // Accounts
   {
@@ -65,7 +66,7 @@ const walletdb = new WalletDB({
       mtx.addOutput(addrs[(i + 1) % addrs.length], 50460);
       mtx.addOutput(addrs[(i + 2) % addrs.length], 50460);
       mtx.addOutput(addrs[(i + 3) % addrs.length], 50460);
-      const tx = mtx.toTX();
+      tx = mtx.toTX();
 
       jobs.push(walletdb.addTX(tx));
     }
@@ -88,7 +89,7 @@ const walletdb = new WalletDB({
       mtx.addOutput(addrs[(i + 1) % addrs.length], 50460);
       mtx.addOutput(addrs[(i + 2) % addrs.length], 50460);
       mtx.addOutput(addrs[(i + 3) % addrs.length], 50460);
-      const tx = mtx.toTX();
+      tx = mtx.toTX();
 
       jobs.push(walletdb.addTX(tx));
     }
diff --git a/bin/node b/bin/node
index e3b15645..3ed9a5ee 100755
--- a/bin/node
+++ b/bin/node
@@ -19,10 +19,9 @@ if (process.argv.indexOf('--version') !== -1
   throw new Error('Could not exit.');
 }
 
-const bcoin = require('../');
-const plugin = require('../lib/wallet/plugin');
+const FullNode = require('../lib/node/fullnode');
 
-const node = new bcoin.fullnode({
+const node = new FullNode({
   config: true,
   argv: true,
   env: true,
@@ -37,8 +36,10 @@ const node = new bcoin.fullnode({
 });
 
 // Temporary hack
-if (!node.config.bool('no-wallet') && !node.has('walletdb'))
+if (!node.config.bool('no-wallet') && !node.has('walletdb')) {
+  const plugin = require('../lib/wallet/plugin');
   node.use(plugin);
+}
 
 process.on('unhandledRejection', (err, promise) => {
   throw err;
diff --git a/bin/spvnode b/bin/spvnode
index d10e981a..71fae73e 100755
--- a/bin/spvnode
+++ b/bin/spvnode
@@ -5,11 +5,11 @@
 process.title = 'bcoin';
 
 const assert = require('assert');
-const bcoin = require('../');
-const plugin = require('../lib/wallet/plugin');
-const util = bcoin.util;
+const SPVNode = require('../lib/node/spvnode');
+const util = require('../lib/utils/util');
+const Outpoint = require('../lib/primitives/outpoint');
 
-const node = bcoin.spvnode({
+const node = SPVNode({
   config: true,
   argv: true,
   env: true,
@@ -24,8 +24,10 @@ const node = bcoin.spvnode({
 });
 
 // Temporary hack
-if (!node.has('walletdb'))
+if (!node.has('walletdb')) {
+  const plugin = require('../lib/wallet/plugin');
   node.use(plugin);
+}
 
 process.on('unhandledRejection', (err, promise) => {
   throw err;
@@ -38,7 +40,7 @@ process.on('unhandledRejection', (err, promise) => {
 
   if (node.config.bool('test')) {
     node.pool.watchAddress('1VayNert3x1KzbpzMGt2qdqrAThiRovi8');
-    node.pool.watchOutpoint(new bcoin.outpoint());
+    node.pool.watchOutpoint(new Outpoint());
     node.on('block', (block) => {
       assert(block.txs.length >= 1);
       if (block.txs.length > 1)
diff --git a/lib/bip70/paymentdetails.js b/lib/bip70/paymentdetails.js
index 746ca5b8..10107e34 100644
--- a/lib/bip70/paymentdetails.js
+++ b/lib/bip70/paymentdetails.js
@@ -141,7 +141,7 @@ PaymentDetails.prototype.getData = function getData(enc) {
   let data = this.merchantData;
 
   if (!data)
-    return;
+    return null;
 
   if (!enc)
     return data;
diff --git a/lib/bip70/x509.js b/lib/bip70/x509.js
index bf9f66d2..87bf3507 100644
--- a/lib/bip70/x509.js
+++ b/lib/bip70/x509.js
@@ -92,6 +92,8 @@ x509.getSubjectOID = function getSubjectOID(cert, oid) {
     if (entry.type === oid)
       return entry.value;
   }
+
+  return null;
 };
 
 /**
diff --git a/lib/blockchain/chain.js b/lib/blockchain/chain.js
index 0607b551..3a4647fd 100644
--- a/lib/blockchain/chain.js
+++ b/lib/blockchain/chain.js
@@ -350,7 +350,7 @@ Chain.prototype.verify = async function verify(block, prev, flags) {
   }
 
   // Check the commitment hash for segwit.
-  let commit = null;
+  let commit;
   if (state.hasWitness()) {
     commit = block.getCommitmentHash();
     if (commit) {
@@ -581,11 +581,12 @@ Chain.prototype.verifyDuplicates = async function verifyDuplicates(block, prev,
  */
 
 Chain.prototype.verifyInputs = async function verifyInputs(block, prev, state) {
+  const view = new CoinView();
+
   if (this.options.spv)
     return view;
 
   const interval = this.network.halvingInterval;
-  const view = new CoinView();
   const height = prev.height + 1;
   const historical = prev.isHistorical();
   const jobs = [];
@@ -1598,7 +1599,7 @@ Chain.prototype.resolveOrphan = function resolveOrphan(hash) {
   const orphan = this.orphanPrev.get(hash);
 
   if (!orphan)
-    return;
+    return null;
 
   return this.removeOrphan(orphan);
 };
@@ -1626,8 +1627,8 @@ Chain.prototype.purgeOrphans = function purgeOrphans() {
 
 Chain.prototype.limitOrphans = function limitOrphans() {
   const now = util.now();
-  let oldest = null;
 
+  let oldest;
   for (const orphan of this.orphanMap.values()) {
     if (now < orphan.time + 60 * 60) {
       if (!oldest || orphan.time < oldest.time)
@@ -1896,9 +1897,9 @@ Chain.prototype._getLocator = async function getLocator(start) {
       hash = await this.db.getHash(height);
       assert(hash);
     } else {
-      const entry = await entry.getAncestor(height);
-      assert(entry);
-      hash = entry.hash;
+      const ancestor = await entry.getAncestor(height);
+      assert(ancestor);
+      hash = ancestor.hash;
     }
 
     hashes.push(hash);
diff --git a/lib/blockchain/chaindb.js b/lib/blockchain/chaindb.js
index f74b6100..8dc842fb 100644
--- a/lib/blockchain/chaindb.js
+++ b/lib/blockchain/chaindb.js
@@ -309,7 +309,7 @@ ChainDB.prototype.getHash = async function getHash(height) {
   assert(typeof height === 'number');
 
   if (height < 0)
-    return;
+    return null;
 
   const entry = this.cacheHeight.get(height);
 
@@ -319,7 +319,7 @@ ChainDB.prototype.getHash = async function getHash(height) {
   const hash = await this.db.get(layout.H(height));
 
   if (!hash)
-    return;
+    return null;
 
   return hash.toString('hex');
 };
@@ -335,26 +335,25 @@ ChainDB.prototype.getEntryByHeight = async function getEntryByHeight(height) {
   assert(typeof height === 'number');
 
   if (height < 0)
-    return;
+    return null;
 
   const cache = this.cacheHeight.get(height);
 
   if (cache)
     return cache;
 
-  let hash = await this.db.get(layout.H(height));
+  const data = await this.db.get(layout.H(height));
 
-  if (!hash)
-    return;
+  if (!data)
+    return null;
 
-  hash = hash.toString('hex');
+  const hash = data.toString('hex');
 
   const state = this.chain.state;
-
   const entry = await this.getEntryByHash(hash);
 
   if (!entry)
-    return;
+    return null;
 
   // By the time getEntry has completed,
   // a reorg may have occurred. This entry
@@ -376,7 +375,7 @@ ChainDB.prototype.getEntryByHash = async function getEntryByHash(hash) {
   assert(typeof hash === 'string');
 
   if (hash === encoding.NULL_HASH)
-    return;
+    return null;
 
   const cache = this.cacheHash.get(hash);
 
@@ -386,7 +385,7 @@ ChainDB.prototype.getEntryByHash = async function getEntryByHash(hash) {
   const raw = await this.db.get(layout.e(hash));
 
   if (!raw)
-    return;
+    return null;
 
   const entry = ChainEntry.fromRaw(this.chain, raw);
 
@@ -441,7 +440,7 @@ ChainDB.prototype.getState = async function getState() {
   const data = await this.db.get(layout.R);
 
   if (!data)
-    return;
+    return null;
 
   return ChainState.fromRaw(data);
 };
@@ -472,7 +471,7 @@ ChainDB.prototype.getFlags = async function getFlags() {
   const data = await this.db.get(layout.O);
 
   if (!data)
-    return;
+    return null;
 
   return ChainFlags.fromRaw(data);
 };
@@ -717,10 +716,11 @@ ChainDB.prototype.prune = async function prune(tip) {
   if (flags.prune)
     throw new Error('Chain is already pruned.');
 
+  const height = await this.getHeight(tip);
+
   if (height <= pruneAfter + keepBlocks)
     return false;
 
-  const height = await this.getHeight(tip);
   const start = pruneAfter + 1;
   const end = height - keepBlocks;
   const batch = this.db.batch();
@@ -765,7 +765,7 @@ ChainDB.prototype.getNextHash = async function getNextHash(hash) {
   const data = await this.db.get(layout.n(hash));
 
   if (!data)
-    return;
+    return null;
 
   return data.toString('hex');
 };
@@ -788,12 +788,12 @@ ChainDB.prototype.isMainChain = async function isMainChain(hash) {
   if (hash === encoding.NULL_HASH)
     return false;
 
-  let entry = this.cacheHash.get(hash);
+  const cacheHash = this.cacheHash.get(hash);
 
-  if (entry) {
-    entry = this.cacheHeight.get(entry.height);
-    if (entry)
-      return entry.hash === hash;
+  if (cacheHash) {
+    const cacheHeight = this.cacheHeight.get(cacheHash.height);
+    if (cacheHeight)
+      return cacheHeight.hash === hash;
   }
 
   if (await this.getNextHash(hash))
@@ -838,7 +838,7 @@ ChainDB.prototype.getTips = function getTips() {
 
 ChainDB.prototype.readCoin = async function readCoin(prevout) {
   if (this.options.spv)
-    return;
+    return null;
 
   const {hash, index} = prevout;
   const key = prevout.toKey();
@@ -852,7 +852,7 @@ ChainDB.prototype.readCoin = async function readCoin(prevout) {
   const raw = await this.db.get(layout.c(hash, index));
 
   if (!raw)
-    return;
+    return null;
 
   if (state === this.state)
     this.coinCache.set(key, raw);
@@ -873,7 +873,7 @@ ChainDB.prototype.getCoin = async function getCoin(hash, index) {
   const coin = await this.readCoin(prevout);
 
   if (!coin)
-    return;
+    return null;
 
   return coin.toCoin(prevout);
 };
@@ -971,7 +971,7 @@ ChainDB.prototype.getBlock = async function getBlock(hash) {
   const data = await this.getRawBlock(hash);
 
   if (!data)
-    return;
+    return null;
 
   return Block.fromRaw(data);
 };
@@ -985,12 +985,12 @@ ChainDB.prototype.getBlock = async function getBlock(hash) {
 
 ChainDB.prototype.getRawBlock = async function getRawBlock(block) {
   if (this.options.spv)
-    return;
+    return null;
 
   const hash = await this.getHash(block);
 
   if (!hash)
-    return;
+    return null;
 
   return await this.db.get(layout.b(hash));
 };
@@ -1033,12 +1033,12 @@ ChainDB.prototype.getBlockView = async function getBlockView(block) {
 
 ChainDB.prototype.getMeta = async function getMeta(hash) {
   if (!this.options.indexTX)
-    return;
+    return null;
 
   const data = await this.db.get(layout.t(hash));
 
   if (!data)
-    return;
+    return null;
 
   return TXMeta.fromRaw(data);
 };
@@ -1052,8 +1052,10 @@ ChainDB.prototype.getMeta = async function getMeta(hash) {
 
 ChainDB.prototype.getTX = async function getTX(hash) {
   const meta = await this.getMeta(hash);
+
   if (!meta)
-    return;
+    return null;
+
   return meta.tx;
 };
 
@@ -1064,7 +1066,7 @@ ChainDB.prototype.getTX = async function getTX(hash) {
 
 ChainDB.prototype.hasTX = function hasTX(hash) {
   if (!this.options.indexTX)
-    return Promise.resolve();
+    return Promise.resolve(false);
 
   return this.db.has(layout.t(hash));
 };
@@ -1077,14 +1079,14 @@ ChainDB.prototype.hasTX = function hasTX(hash) {
  */
 
 ChainDB.prototype.getCoinsByAddress = async function getCoinsByAddress(addrs) {
-  const coins = [];
-
   if (!this.options.indexAddress)
-    return coins;
+    return [];
 
   if (!Array.isArray(addrs))
     addrs = [addrs];
 
+  const coins = [];
+
   for (const addr of addrs) {
     const hash = Address.getHash(addr);
 
@@ -1112,11 +1114,11 @@ ChainDB.prototype.getCoinsByAddress = async function getCoinsByAddress(addrs) {
  */
 
 ChainDB.prototype.getHashesByAddress = async function getHashesByAddress(addrs) {
-  const hashes = Object.create(null);
-
   if (!this.options.indexTX || !this.options.indexAddress)
     return [];
 
+  const hashes = Object.create(null);
+
   for (const addr of addrs) {
     const hash = Address.getHash(addr);
 
@@ -1158,15 +1160,14 @@ ChainDB.prototype.getTXByAddress = async function getTXByAddress(addrs) {
  */
 
 ChainDB.prototype.getMetaByAddress = async function getTXByAddress(addrs) {
-  const txs = [];
-
   if (!this.options.indexTX || !this.options.indexAddress)
-    return txs;
+    return [];
 
   if (!Array.isArray(addrs))
     addrs = [addrs];
 
   const hashes = await this.getHashesByAddress(addrs);
+  const txs = [];
 
   for (const hash of hashes) {
     const tx = await this.getMeta(hash);
@@ -1638,7 +1639,7 @@ ChainDB.prototype.saveBlock = async function saveBlock(entry, block, view) {
 
 ChainDB.prototype.removeBlock = async function removeBlock(entry) {
   if (this.options.spv)
-    return;
+    return new CoinView();
 
   const block = await this.getBlock(entry.hash);
 
@@ -1734,10 +1735,11 @@ ChainDB.prototype.connectBlock = async function connectBlock(entry, block, view)
  */
 
 ChainDB.prototype.disconnectBlock = async function disconnectBlock(entry, block) {
+  const view = new CoinView();
+
   if (this.options.spv)
     return view;
 
-  const view = new CoinView();
   const hash = block.hash();
   const undo = await this.getUndoCoins(hash);
 
diff --git a/lib/blockchain/chainentry.js b/lib/blockchain/chainentry.js
index e64dca74..3425e866 100644
--- a/lib/blockchain/chainentry.js
+++ b/lib/blockchain/chainentry.js
@@ -130,8 +130,10 @@ ChainEntry.fromOptions = function fromOptions(chain, options, prev) {
 
 ChainEntry.prototype.getProof = function getProof() {
   const target = consensus.fromCompact(this.bits);
+
   if (target.isNeg() || target.cmpn(0) === 0)
     return new BN(0);
+
   return ChainEntry.MAX_CHAINWORK.div(target.iaddn(1));
 };
 
@@ -194,7 +196,7 @@ ChainEntry.prototype.isMainChain = async function isMainChain() {
 
 ChainEntry.prototype.getAncestor = async function getAncestor(height) {
   if (height < 0)
-    return;
+    return null;
 
   assert(height >= 0);
   assert(height <= this.height);
@@ -237,8 +239,10 @@ ChainEntry.prototype.getPrevCache = function getPrevCache() {
 
 ChainEntry.prototype.getNext = async function getNext() {
   const hash = await this.chain.db.getNextHash(this.hash);
+
   if (!hash)
-    return;
+    return null;
+
   return await this.chain.db.getEntry(hash);
 };
 
@@ -252,11 +256,11 @@ ChainEntry.prototype.getNextEntry = async function getNextEntry() {
   const entry = await this.chain.db.getEntry(this.height + 1);
 
   if (!entry)
-    return;
+    return null;
 
   // Not on main chain.
   if (entry.prevBlock !== this.hash)
-    return;
+    return null;
 
   return entry;
 };
diff --git a/lib/blockchain/layout-browser.js b/lib/blockchain/layout-browser.js
index 03b3fd49..e26b4082 100644
--- a/lib/blockchain/layout-browser.js
+++ b/lib/blockchain/layout-browser.js
@@ -75,10 +75,9 @@ const layout = {
     return key.slice(1, 65);
   },
   Cc: function Cc(key) {
-    let hash, index;
-
     assert(typeof key === 'string');
 
+    let hash, index;
     if (key.length === 139) {
       hash = key.slice(65, 129);
       index = +key.slice(129);
diff --git a/lib/blockchain/layout.js b/lib/blockchain/layout.js
index c3653121..677b2fe3 100644
--- a/lib/blockchain/layout.js
+++ b/lib/blockchain/layout.js
@@ -76,11 +76,11 @@ const layout = {
   },
   T: function T(addr, hash) {
     let len = addr.length;
-    let key;
 
     if (typeof addr === 'string')
       len /= 2;
 
+    let key;
     if (len === 32) {
       key = Buffer.allocUnsafe(65);
       key[0] = 0xab; // W + T
@@ -99,13 +99,13 @@ const layout = {
   },
   C: function C(addr, hash, index) {
     let len = addr.length;
-    let key;
 
     assert(typeof index === 'number');
 
     if (typeof addr === 'string')
       len /= 2;
 
+    let key;
     if (len === 32) {
       key = Buffer.allocUnsafe(69);
       key[0] = 0x9a; // W + C
@@ -130,10 +130,9 @@ const layout = {
     return key.toString('hex', 1, 33);
   },
   Cc: function Cc(key) {
-    let hash, index;
-
     assert(Buffer.isBuffer(key));
 
+    let hash, index;
     if (key.length === 69) {
       hash = key.toString('hex', 33, 65);
       index = key.readUInt32BE(65, 0);
@@ -165,7 +164,7 @@ function write(data, str, off) {
   if (Buffer.isBuffer(str))
     return str.copy(data, off);
   assert(typeof str === 'string');
-  data.write(str, off, 'hex');
+  return data.write(str, off, 'hex');
 }
 
 function pair(prefix, hash) {
diff --git a/lib/coins/compress.js b/lib/coins/compress.js
index 74ed2029..108e6e8a 100644
--- a/lib/coins/compress.js
+++ b/lib/coins/compress.js
@@ -334,6 +334,10 @@ function decompressKey(key) {
   return out;
 }
 
+// Make eslint happy.
+compressValue;
+decompressValue;
+
 /*
  * Expose
  */
diff --git a/lib/crypto/aead.js b/lib/crypto/aead.js
index 4295252d..84ee6b57 100644
--- a/lib/crypto/aead.js
+++ b/lib/crypto/aead.js
@@ -123,8 +123,7 @@ AEAD.prototype.auth = function auth(data) {
 
 AEAD.prototype.finish = function finish() {
   const len = Buffer.allocUnsafe(16);
-  let lo = 0;
-  let hi = 0;
+  let lo, hi;
 
   // The RFC says these are supposed to be
   // uint32le, but their own fucking test
diff --git a/lib/crypto/aes-browser.js b/lib/crypto/aes-browser.js
index 34060170..96b357be 100644
--- a/lib/crypto/aes-browser.js
+++ b/lib/crypto/aes-browser.js
@@ -8,6 +8,8 @@
  * Entered into the public domain by Vincent Rijmen.
  */
 
+/* eslint no-use-before-define: "off" */
+
 'use strict';
 
 const assert = require('assert');
diff --git a/lib/crypto/ccmp.js b/lib/crypto/ccmp.js
index 45c9eef7..dfc4ced1 100644
--- a/lib/crypto/ccmp.js
+++ b/lib/crypto/ccmp.js
@@ -6,6 +6,8 @@
 
 'use strict';
 
+const assert = require('assert');
+
 /**
  * memcmp in constant time (can only return true or false).
  * This protects us against timing attacks when
@@ -19,11 +21,8 @@
  */
 
 module.exports = function ccmp(a, b) {
-  if (!Buffer.isBuffer(a))
-    return false;
-
-  if (!Buffer.isBuffer(b))
-    return false;
+  assert(Buffer.isBuffer(a));
+  assert(Buffer.isBuffer(b));
 
   if (b.length === 0)
     return a.length === 0;
diff --git a/lib/crypto/hmac-drbg.js b/lib/crypto/hmac-drbg.js
index ead618c3..55980794 100644
--- a/lib/crypto/hmac-drbg.js
+++ b/lib/crypto/hmac-drbg.js
@@ -95,12 +95,12 @@ HmacDRBG.prototype.update = function update(seed) {
 };
 
 HmacDRBG.prototype.generate = function generate(len) {
-  const data = Buffer.allocUnsafe(len);
-  let pos = 0;
-
   if (this.rounds > RESEED_INTERVAL)
     throw new Error('Reseed is required.');
 
+  const data = Buffer.allocUnsafe(len);
+  let pos = 0;
+
   while (pos < len) {
     this.V = digest.hmac(HASH_ALG, this.V, this.K);
     this.V.copy(data, pos);
diff --git a/lib/crypto/poly1305.js b/lib/crypto/poly1305.js
index 33e7f96f..50ecdda9 100644
--- a/lib/crypto/poly1305.js
+++ b/lib/crypto/poly1305.js
@@ -155,15 +155,21 @@ Poly1305.prototype.update = function update(data) {
   // handle leftover
   if (this.leftover) {
     let want = 16 - this.leftover;
+
     if (want > bytes)
       want = bytes;
+
     for (let i = 0; i < want; i++)
       this.buffer[this.leftover + i] = data[m + i];
+
     bytes -= want;
     m += want;
+
     this.leftover += want;
+
     if (this.leftover < 16)
       return;
+
     this.blocks(this.buffer, 16, 0);
     this.leftover = 0;
   }
@@ -262,8 +268,10 @@ Poly1305.prototype.finish = function finish() {
   // zero out the state
   for (let i = 0; i < 10; i++)
     this.h[i] = 0;
+
   for (let i = 0; i < 10; i++)
     this.r[i] = 0;
+
   for (let i = 0; i < 8; i++)
     this.pad[i] = 0;
 
diff --git a/lib/crypto/schnorr.js b/lib/crypto/schnorr.js
index 75529c7d..f10657d8 100644
--- a/lib/crypto/schnorr.js
+++ b/lib/crypto/schnorr.js
@@ -101,12 +101,12 @@ schnorr.sign = function sign(msg, key, pubNonce) {
   const prv = new BN(key);
   const drbg = schnorr.drbg(msg, key, pubNonce);
   const len = curve.n.byteLength();
-  let pn = null;
-  let sig = null;
 
+  let pn;
   if (pubNonce)
     pn = curve.decodePoint(pubNonce);
 
+  let sig;
   while (!sig) {
     const k = new BN(drbg.generate(len));
     sig = schnorr.trySign(msg, prv, k, pn);
@@ -210,8 +210,7 @@ schnorr.recover = function recover(signature, msg) {
 
 schnorr.combineSigs = function combineSigs(sigs) {
   let s = new BN(0);
-  let r = null;
-  let last = null;
+  let r, last;
 
   for (let i = 0; i < sigs.length; i++) {
     const sig = new Signature(sigs[i]);
@@ -325,8 +324,8 @@ schnorr.drbg = function drbg(msg, priv, data) {
 schnorr.generateNoncePair = function generateNoncePair(msg, priv, data) {
   const drbg = schnorr.drbg(msg, priv, data);
   const len = curve.n.byteLength();
-  let k;
 
+  let k;
   for (;;) {
     k = new BN(drbg.generate(len));
 
diff --git a/lib/crypto/secp256k1-browser.js b/lib/crypto/secp256k1-browser.js
index b1e3908c..023e2953 100644
--- a/lib/crypto/secp256k1-browser.js
+++ b/lib/crypto/secp256k1-browser.js
@@ -146,7 +146,7 @@ ec.recover = function recover(msg, sig, j, compress) {
   try {
     point = secp256k1.recoverPubKey(msg, sig, j);
   } catch (e) {
-    return;
+    return null;
   }
 
   return Buffer.from(point.encode('array', compress));
@@ -191,7 +191,8 @@ ec.verify = function verify(msg, sig, key) {
 
 ec.publicKeyVerify = function publicKeyVerify(key) {
   try {
-    return secp256k1.keyPair({ pub: key }).validate();
+    const pub = secp256k1.keyPair({ pub: key });
+    return pub.validate();
   } catch (e) {
     return false;
   }
@@ -324,13 +325,14 @@ function normalizeLength(sig) {
 
 function getLength(buf, p) {
   const initial = buf[p.place++];
-  const len = initial & 0xf;
-  let off = p.place;
-  let val = 0;
 
   if (!(initial & 0x80))
     return initial;
 
+  const len = initial & 0xf;
+  let off = p.place;
+  let val = 0;
+
   for (let i = 0; i < len; i++, off++) {
     val <<= 8;
     val |= buf[off];
diff --git a/lib/crypto/secp256k1-native.js b/lib/crypto/secp256k1-native.js
index b8340155..139032a5 100644
--- a/lib/crypto/secp256k1-native.js
+++ b/lib/crypto/secp256k1-native.js
@@ -127,13 +127,13 @@ ec.recover = function recover(msg, sig, j, compress) {
   try {
     sig = secp256k1.signatureImport(sig);
   } catch (e) {
-    return;
+    return null;
   }
 
   try {
     key = secp256k1.recover(msg, sig, j, compress);
   } catch (e) {
-    return;
+    return null;
   }
 
   return key;
@@ -195,13 +195,11 @@ ec.privateKeyVerify = function privateKeyVerify(key) {
  */
 
 ec.sign = function sign(msg, key) {
-  let sig;
-
   assert(Buffer.isBuffer(msg));
   assert(Buffer.isBuffer(key));
 
   // Sign message
-  sig = secp256k1.sign(msg, key);
+  let sig = secp256k1.sign(msg, key);
 
   // Ensure low S value
   sig = secp256k1.signatureNormalize(sig.signature);
@@ -239,10 +237,10 @@ ec.toDER = function toDER(sig) {
  */
 
 ec.isLowS = function isLowS(sig) {
-  let rs, s;
+  let s;
 
   try {
-    rs = secp256k1.signatureImport(sig);
+    const rs = secp256k1.signatureImport(sig);
     s = rs.slice(32, 64);
   } catch (e) {
     return false;
diff --git a/lib/crypto/sha256.js b/lib/crypto/sha256.js
index 0dc4c202..5262faca 100644
--- a/lib/crypto/sha256.js
+++ b/lib/crypto/sha256.js
@@ -167,6 +167,7 @@ SHA256.prototype._finish = function _finish(out) {
  */
 
 SHA256.prototype.transform = function transform(chunk, pos) {
+  const w = this.w;
   let a = this.s[0];
   let b = this.s[1];
   let c = this.s[2];
@@ -175,7 +176,6 @@ SHA256.prototype.transform = function transform(chunk, pos) {
   let f = this.s[5];
   let g = this.s[6];
   let h = this.s[7];
-  const w = this.w;
   let i = 0;
 
   for (; i < 16; i++)
@@ -185,13 +185,11 @@ SHA256.prototype.transform = function transform(chunk, pos) {
     w[i] = sigma1(w[i - 2]) + w[i - 7] + sigma0(w[i - 15]) + w[i - 16];
 
   for (i = 0; i < 64; i++) {
-    let t1, t2;
-
-    t1 = h + Sigma1(e);
+    let t1 = h + Sigma1(e);
     t1 += Ch(e, f, g);
     t1 += K[i] + w[i];
 
-    t2 = Sigma0(a);
+    let t2 = Sigma0(a);
     t2 += Maj(a, b, c);
 
     h = g;
diff --git a/lib/crypto/siphash.js b/lib/crypto/siphash.js
index 23b40328..08b5c4b3 100644
--- a/lib/crypto/siphash.js
+++ b/lib/crypto/siphash.js
@@ -33,7 +33,6 @@ function siphash24(data, key, shift) {
   const f1 = U64(0, 0xff);
   const k0 = U64.fromRaw(key, 0);
   const k1 = U64.fromRaw(key, 8);
-  let p = 0;
 
   // Init
   const v0 = c0.ixor(k0);
@@ -42,6 +41,7 @@ function siphash24(data, key, shift) {
   const v3 = c3.ixor(k1);
 
   // Blocks
+  let p = 0;
   for (let i = 0; i < blocks; i++) {
     const d = U64.fromRaw(data, p);
     p += 8;
diff --git a/lib/db/lowlevelup.js b/lib/db/lowlevelup.js
index 97dda37e..8c3ec862 100644
--- a/lib/db/lowlevelup.js
+++ b/lib/db/lowlevelup.js
@@ -271,7 +271,7 @@ LowlevelUp.prototype.get = function get(key) {
     this.binding.get(key, (err, result) => {
       if (err) {
         if (isNotFound(err)) {
-          resolve();
+          resolve(null);
           return;
         }
         reject(err);
diff --git a/lib/db/memdb.js b/lib/db/memdb.js
index 327a9b24..0c8a36b6 100644
--- a/lib/db/memdb.js
+++ b/lib/db/memdb.js
@@ -45,7 +45,7 @@ MemDB.prototype.search = function search(key) {
   const node = this.tree.search(key);
 
   if (!node)
-    return;
+    return undefined;
 
   return node.value;
 };
@@ -449,13 +449,13 @@ Iterator.prototype.init = function init() {
 Iterator.prototype.next = function next(callback) {
   const options = this.options;
   const iter = this.iter;
-  let key, value, result;
 
   if (!this.iter) {
     setImmediate(() => callback(new Error('Cannot call next.')));
     return;
   }
 
+  let result;
   if (options.reverse) {
     result = iter.prev();
 
@@ -499,8 +499,8 @@ Iterator.prototype.next = function next(callback) {
     this.total += 1;
   }
 
-  key = iter.key;
-  value = iter.value;
+  let key = iter.key;
+  let value = iter.value;
 
   if (!options.keys)
     key = DUMMY;
diff --git a/lib/hd/common.js b/lib/hd/common.js
index 97f98e5f..038639cc 100644
--- a/lib/hd/common.js
+++ b/lib/hd/common.js
@@ -65,13 +65,12 @@ common.cache = new LRU(500);
  */
 
 common.parsePath = function parsePath(path, max) {
-  const parts = path.split('/');
-  const root = parts.shift();
-  const result = [];
-
   if (max == null)
     max = common.MAX_INDEX;
 
+  const parts = path.split('/');
+  const root = parts.shift();
+
   if (root !== 'm'
       && root !== 'M'
       && root !== 'm\''
@@ -79,6 +78,8 @@ common.parsePath = function parsePath(path, max) {
     throw new Error('Bad path root.');
   }
 
+  const result = [];
+
   for (let index of parts) {
     const hardened = index[index.length - 1] === '\'';
 
diff --git a/lib/hd/mnemonic.js b/lib/hd/mnemonic.js
index f0a4bf12..a086cac1 100644
--- a/lib/hd/mnemonic.js
+++ b/lib/hd/mnemonic.js
@@ -177,11 +177,6 @@ Mnemonic.prototype.getPhrase = function getPhrase() {
   if (this.phrase)
     return this.phrase;
 
-  let phrase = [];
-  const wordlist = Mnemonic.getWordlist(this.language);
-
-  const ent = this.getEntropy();
-
   // Include the first `ENT / 32` bits
   // of the hash (the checksum).
   const bits = this.bits + (this.bits / 32);
@@ -189,12 +184,16 @@ Mnemonic.prototype.getPhrase = function getPhrase() {
   // Append the hash to the entropy to
   // make things easy when grabbing
   // the checksum bits.
+  const ent = this.getEntropy();
   const entropy = Buffer.allocUnsafe(Math.ceil(bits / 8));
   ent.copy(entropy, 0);
   digest.sha256(ent).copy(entropy, ent.length);
 
   // Build the mnemonic by reading
   // 11 bit indexes from the entropy.
+  const wordlist = Mnemonic.getWordlist(this.language);
+
+  let phrase = [];
   for (let i = 0; i < bits / 11; i++) {
     let index = 0;
     for (let j = 0; j < 11; j++) {
diff --git a/lib/hd/private.js b/lib/hd/private.js
index 91b682f2..f1e48755 100644
--- a/lib/hd/private.js
+++ b/lib/hd/private.js
@@ -413,11 +413,9 @@ HDPrivateKey.prototype.equal = function equal(obj) {
  */
 
 HDPrivateKey.prototype.compare = function compare(key) {
-  let cmp;
-
   assert(HDPrivateKey.isHDPrivateKey(key));
 
-  cmp = this.depth - key.depth;
+  let cmp = this.depth - key.depth;
 
   if (cmp !== 0)
     return cmp;
diff --git a/lib/hd/public.js b/lib/hd/public.js
index f2ae4b4c..33b014a0 100644
--- a/lib/hd/public.js
+++ b/lib/hd/public.js
@@ -335,11 +335,9 @@ HDPublicKey.prototype.equal = function equal(obj) {
  */
 
 HDPublicKey.prototype.compare = function compare(key) {
-  let cmp;
-
   assert(HDPublicKey.isHDPublicKey(key));
 
-  cmp = this.depth - key.depth;
+  let cmp = this.depth - key.depth;
 
   if (cmp !== 0)
     return cmp;
diff --git a/lib/http/base.js b/lib/http/base.js
index fdda42b6..b5532e40 100644
--- a/lib/http/base.js
+++ b/lib/http/base.js
@@ -186,16 +186,22 @@ HTTPBase.prototype.basicAuth = function basicAuth(options) {
   let realm = options.realm;
 
   if (user) {
-    if (typeof user === 'string')
+    if (typeof user === 'string') {
+      assert(user.length <= 255, 'Username too long.');
       user = Buffer.from(user, 'utf8');
+    }
     assert(Buffer.isBuffer(user));
+    assert(user.length <= 255, 'Username too long.');
     user = digest.hash256(user);
   }
 
-  if (typeof pass === 'string')
+  if (typeof pass === 'string') {
+    assert(pass.length <= 255, 'Password too long.');
     pass = Buffer.from(pass, 'utf8');
+  }
 
   assert(Buffer.isBuffer(pass));
+  assert(pass.length <= 255, 'Password too long.');
   pass = digest.hash256(pass);
 
   if (!realm)
@@ -215,6 +221,9 @@ HTTPBase.prototype.basicAuth = function basicAuth(options) {
     if (!hdr)
       return fail(res);
 
+    if (hdr.length > 1000)
+      return fail(res);
+
     const parts = hdr.split(' ');
 
     if (parts.length !== 2)
@@ -230,6 +239,9 @@ HTTPBase.prototype.basicAuth = function basicAuth(options) {
     const password = items.join(':');
 
     if (user) {
+      if (username.length > 255)
+        return fail(res);
+
       const raw = Buffer.from(username, 'utf8');
       const hash = digest.hash256(raw);
 
@@ -237,6 +249,9 @@ HTTPBase.prototype.basicAuth = function basicAuth(options) {
         return fail(res);
     }
 
+    if (password.length > 255)
+      return fail(res);
+
     const raw = Buffer.from(password, 'utf8');
     const hash = digest.hash256(raw);
 
@@ -345,7 +360,9 @@ HTTPBase.prototype._readBody = function _readBody(req, enc, options, resolve, re
     reject(new Error('Request body timed out.'));
   }, options.timeout);
 
-  let cleanup = () => {
+  /* eslint no-use-before-define: "off" */
+
+  const cleanup = () => {
     req.removeListener('data', onData);
     req.removeListener('error', onError);
     req.removeListener('end', onEnd);
@@ -356,7 +373,7 @@ HTTPBase.prototype._readBody = function _readBody(req, enc, options, resolve, re
     }
   };
 
-  let onData = (data) => {
+  const onData = (data) => {
     total += data.length;
     hasData = true;
 
@@ -368,12 +385,12 @@ HTTPBase.prototype._readBody = function _readBody(req, enc, options, resolve, re
     body += decode.write(data);
   };
 
-  let onError = (err) => {
+  const onError = (err) => {
     cleanup();
     reject(err);
   };
 
-  let onEnd = () => {
+  const onEnd = () => {
     cleanup();
 
     if (hasData) {
@@ -493,11 +510,10 @@ HTTPBase.prototype.handleHooks = async function handleHooks(req, res) {
  */
 
 HTTPBase.prototype._initSockets = function _initSockets() {
-  let IOServer;
-
   if (!this.config.sockets)
     return;
 
+  let IOServer;
   try {
     IOServer = require('socket.io');
   } catch (e) {
@@ -608,12 +624,13 @@ HTTPBase.prototype.removeSocket = function removeSocket(socket) {
  */
 
 HTTPBase.prototype.joinChannel = function joinChannel(socket, name) {
-  let list = this.channels.get(name);
   let item = socket.channels.get(name);
 
   if (item)
     return;
 
+  let list = this.channels.get(name);
+
   if (!list) {
     list = new List();
     this.channels.set(name, list);
@@ -633,12 +650,13 @@ HTTPBase.prototype.joinChannel = function joinChannel(socket, name) {
  */
 
 HTTPBase.prototype.leaveChannel = function leaveChannel(socket, name) {
-  const list = this.channels.get(name);
   const item = socket.channels.get(name);
 
   if (!item)
     return;
 
+  const list = this.channels.get(name);
+
   assert(list);
   assert(list.remove(item));
 
@@ -658,7 +676,7 @@ HTTPBase.prototype.channel = function channel(name) {
   const list = this.channels.get(name);
 
   if (!list)
-    return;
+    return null;
 
   assert(list.size > 0);
 
@@ -1088,7 +1106,7 @@ Route.prototype.match = function _match(pathname) {
   const match = this.regex.exec(pathname);
 
   if (!match)
-    return;
+    return null;
 
   const params = Object.create(null);
 
@@ -1135,7 +1153,7 @@ function Routes() {
 
 Routes.prototype.getHandlers = function getHandlers(method) {
   if (!method)
-    return;
+    return null;
 
   method = method.toUpperCase();
 
@@ -1149,7 +1167,7 @@ Routes.prototype.getHandlers = function getHandlers(method) {
     case 'DELETE':
       return this.del;
     default:
-      return;
+      return null;
   }
 };
 
@@ -1535,13 +1553,14 @@ WebSocket.prototype.init = function init() {
 WebSocket.prototype.onevent = async function onevent(packet) {
   const args = (packet.data || []).slice();
   const type = args.shift() || '';
-  let ack, result;
 
+  let ack;
   if (typeof args[args.length - 1] === 'function')
     ack = args.pop();
   else
     ack = this.socket.ack(packet.id);
 
+  let result;
   try {
     result = await this.fire(type, args);
   } catch (e) {
@@ -1568,7 +1587,7 @@ WebSocket.prototype.fire = async function fire(type, args) {
   const handler = this.hooks[type];
 
   if (!handler)
-    return;
+    return undefined;
 
   return await handler.call(this.context, args);
 };
@@ -1617,8 +1636,8 @@ function parsePairs(str, limit) {
 
   for (const pair of parts) {
     const index = pair.indexOf('=');
-    let key, value;
 
+    let key, value;
     if (index === -1) {
       key = pair;
       value = '';
diff --git a/lib/http/client.js b/lib/http/client.js
index f80a28bf..c5f850dc 100644
--- a/lib/http/client.js
+++ b/lib/http/client.js
@@ -195,14 +195,13 @@ HTTPClient.prototype.onDisconnect = function onDisconnect() {
  */
 
 HTTPClient.prototype._request = async function _request(method, endpoint, json) {
-  let query;
-
   if (this.token) {
     if (!json)
       json = {};
     json.token = this.token;
   }
 
+  let query;
   if (json && method === 'get') {
     query = json;
     json = null;
@@ -221,7 +220,7 @@ HTTPClient.prototype._request = async function _request(method, endpoint, json)
   });
 
   if (res.statusCode === 404)
-    return;
+    return null;
 
   if (res.statusCode === 401)
     throw new Error('Unauthorized (bad API key).');
@@ -457,22 +456,6 @@ HTTPClient.prototype.leave = function leave(id) {
   });
 };
 
-/**
- * Listen for events on all wallets.
- */
-
-HTTPClient.prototype.all = function all(token) {
-  return this.join('!all', token);
-};
-
-/**
- * Unlisten for events on all wallets.
- */
-
-HTTPClient.prototype.none = function none() {
-  return this.leave('!all');
-};
-
 /**
  * Get list of all wallet IDs.
  * @returns {Promise}
@@ -974,7 +957,7 @@ HTTPClient.prototype.createNested = function createNested(id, options) {
 
 function toHex(obj) {
   if (!obj)
-    return;
+    return null;
 
   if (obj.toRaw)
     obj = obj.toRaw();
diff --git a/lib/http/request.js b/lib/http/request.js
index 2cc3f509..bcc1da38 100644
--- a/lib/http/request.js
+++ b/lib/http/request.js
@@ -424,8 +424,6 @@ Request.prototype.finish = function finish(err) {
 };
 
 Request.prototype._onResponse = function _onResponse(response) {
-  let type = response.headers['content-type'];
-  const length = response.headers['content-length'];
   const location = response.headers['location'];
 
   if (location) {
@@ -440,13 +438,16 @@ Request.prototype._onResponse = function _onResponse(response) {
     return;
   }
 
-  type = parseType(type);
+  const contentType = response.headers['content-type'];
+  const type = parseType(contentType);
 
   if (!this.options.isExpected(type)) {
     this.finish(new Error('Wrong content-type for response.'));
     return;
   }
 
+  const length = response.headers['content-length'];
+
   if (this.options.isOverflow(length)) {
     this.finish(new Error('Response exceeded limit.'));
     return;
diff --git a/lib/http/rpc.js b/lib/http/rpc.js
index 2449059b..2f3aba88 100644
--- a/lib/http/rpc.js
+++ b/lib/http/rpc.js
@@ -24,6 +24,7 @@ const KeyRing = require('../primitives/keyring');
 const MerkleBlock = require('../primitives/merkleblock');
 const MTX = require('../primitives/mtx');
 const Network = require('../protocol/network');
+const Outpoint = require('../primitives/outpoint');
 const Output = require('../primitives/output');
 const TX = require('../primitives/tx');
 const IP = require('../utils/ip');
@@ -214,12 +215,12 @@ RPC.prototype.stop = async function stop(args, help) {
  */
 
 RPC.prototype.getNetworkInfo = async function getNetworkInfo(args, help) {
-  const hosts = this.pool.hosts;
-  const locals = [];
-
   if (help || args.length !== 0)
     throw new RPCError(errs.MISC_ERROR, 'getnetworkinfo');
 
+  const hosts = this.pool.hosts;
+  const locals = [];
+
   for (const local of hosts.local.values()) {
     locals.push({
       address: local.addr.host,
@@ -246,13 +247,13 @@ RPC.prototype.getNetworkInfo = async function getNetworkInfo(args, help) {
 };
 
 RPC.prototype.addNode = async function addNode(args, help) {
+  if (help || args.length !== 2)
+    throw new RPCError(errs.MISC_ERROR, 'addnode "node" "add|remove|onetry"');
+
   const valid = new Validator([args]);
   const node = valid.str(0, '');
   const cmd = valid.str(1, '');
 
-  if (help || args.length !== 2)
-    throw new RPCError(errs.MISC_ERROR, 'addnode "node" "add|remove|onetry"');
-
   switch (cmd) {
     case 'add': {
       this.pool.hosts.addNode(node);
@@ -278,12 +279,12 @@ RPC.prototype.addNode = async function addNode(args, help) {
 };
 
 RPC.prototype.disconnectNode = async function disconnectNode(args, help) {
-  const valid = new Validator([args]);
-  const str = valid.str(0, '');
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'disconnectnode "node"');
 
+  const valid = new Validator([args]);
+  const str = valid.str(0, '');
+
   const addr = parseIP(str, this.network);
   const peer = this.pool.peers.get(addr.hostname);
 
@@ -294,18 +295,19 @@ RPC.prototype.disconnectNode = async function disconnectNode(args, help) {
 };
 
 RPC.prototype.getAddedNodeInfo = async function getAddedNodeInfo(args, help) {
-  const hosts = this.pool.hosts;
-  const valid = new Validator([args]);
-  const addr = valid.str(0, '');
-  const result = [];
-  let target = null;
-
   if (help || args.length > 1)
     throw new RPCError(errs.MISC_ERROR, 'getaddednodeinfo ( "node" )');
 
+  const hosts = this.pool.hosts;
+  const valid = new Validator([args]);
+  const addr = valid.str(0, '');
+
+  let target;
   if (args.length === 1)
     target = parseIP(addr, this.network);
 
+  const result = [];
+
   for (const node of hosts.nodes) {
     if (target) {
       if (node.host !== target.host)
@@ -375,11 +377,11 @@ RPC.prototype.getNetTotals = async function getNetTotals(args, help) {
 };
 
 RPC.prototype.getPeerInfo = async function getPeerInfo(args, help) {
-  const peers = [];
-
   if (help || args.length !== 0)
     throw new RPCError(errs.MISC_ERROR, 'getpeerinfo');
 
+  const peers = [];
+
   for (let peer = this.pool.peers.head(); peer; peer = peer.next) {
     let offset = this.network.time.known.get(peer.hostname());
     const hashes = [];
@@ -462,11 +464,11 @@ RPC.prototype.setBan = async function setBan(args, help) {
 };
 
 RPC.prototype.listBanned = async function listBanned(args, help) {
-  const banned = [];
-
   if (help || args.length !== 0)
     throw new RPCError(errs.MISC_ERROR, 'listbanned');
 
+  const banned = [];
+
   for (const [host, time] of this.pool.hosts.banned) {
     banned.push({
       address: host,
@@ -528,14 +530,14 @@ RPC.prototype.getBlockCount = async function getBlockCount(args, help) {
 };
 
 RPC.prototype.getBlock = async function getBlock(args, help) {
+  if (help || args.length < 1 || args.length > 3)
+    throw new RPCError(errs.MISC_ERROR, 'getblock "hash" ( verbose )');
+
   const valid = new Validator([args]);
   const hash = valid.hash(0);
   const verbose = valid.bool(1, true);
   const details = valid.bool(2, false);
 
-  if (help || args.length < 1 || args.length > 3)
-    throw new RPCError(errs.MISC_ERROR, 'getblock "hash" ( verbose )');
-
   if (!hash)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid block hash.');
 
@@ -563,16 +565,16 @@ RPC.prototype.getBlock = async function getBlock(args, help) {
 };
 
 RPC.prototype.getBlockByHeight = async function getBlockByHeight(args, help) {
-  const valid = new Validator([args]);
-  const height = valid.u32(0, -1);
-  const verbose = valid.bool(1, true);
-  const details = valid.bool(2, false);
-
   if (help || args.length < 1 || args.length > 3) {
     throw new RPCError(errs.MISC_ERROR,
       'getblockbyheight "height" ( verbose )');
   }
 
+  const valid = new Validator([args]);
+  const height = valid.u32(0, -1);
+  const verbose = valid.bool(1, true);
+  const details = valid.bool(2, false);
+
   if (height === -1)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid block height.');
 
@@ -600,12 +602,12 @@ RPC.prototype.getBlockByHeight = async function getBlockByHeight(args, help) {
 };
 
 RPC.prototype.getBlockHash = async function getBlockHash(args, help) {
-  const valid = new Validator([args]);
-  const height = valid.u32(0);
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'getblockhash index');
 
+  const valid = new Validator([args]);
+  const height = valid.u32(0);
+
   if (height == null || height > this.chain.height)
     throw new RPCError(errs.INVALID_PARAMETER, 'Block height out of range.');
 
@@ -618,13 +620,13 @@ RPC.prototype.getBlockHash = async function getBlockHash(args, help) {
 };
 
 RPC.prototype.getBlockHeader = async function getBlockHeader(args, help) {
+  if (help || args.length < 1 || args.length > 2)
+    throw new RPCError(errs.MISC_ERROR, 'getblockheader "hash" ( verbose )');
+
   const valid = new Validator([args]);
   const hash = valid.hash(0);
   const verbose = valid.bool(1, true);
 
-  if (help || args.length < 1 || args.length > 2)
-    throw new RPCError(errs.MISC_ERROR, 'getblockheader "hash" ( verbose )');
-
   if (!hash)
     throw new RPCError(errs.MISC_ERROR, 'Invalid block hash.');
 
@@ -689,13 +691,12 @@ RPC.prototype.getMempoolInfo = async function getMempoolInfo(args, help) {
 };
 
 RPC.prototype.getMempoolAncestors = async function getMempoolAncestors(args, help) {
+  if (help || args.length < 1 || args.length > 2)
+    throw new RPCError(errs.MISC_ERROR, 'getmempoolancestors txid (verbose)');
+
   const valid = new Validator([args]);
   const hash = valid.hash(0);
   const verbose = valid.bool(1, false);
-  const out = [];
-
-  if (help || args.length < 1 || args.length > 2)
-    throw new RPCError(errs.MISC_ERROR, 'getmempoolancestors txid (verbose)');
 
   if (!this.mempool)
     throw new RPCError(errs.MISC_ERROR, 'No mempool available.');
@@ -709,6 +710,7 @@ RPC.prototype.getMempoolAncestors = async function getMempoolAncestors(args, hel
     throw new RPCError(errs.MISC_ERROR, 'Transaction not in mempool.');
 
   const entries = this.mempool.getAncestors(entry);
+  const out = [];
 
   if (verbose) {
     for (const entry of entries)
@@ -722,13 +724,12 @@ RPC.prototype.getMempoolAncestors = async function getMempoolAncestors(args, hel
 };
 
 RPC.prototype.getMempoolDescendants = async function getMempoolDescendants(args, help) {
+  if (help || args.length < 1 || args.length > 2)
+    throw new RPCError(errs.MISC_ERROR, 'getmempooldescendants txid (verbose)');
+
   const valid = new Validator([args]);
   const hash = valid.hash(0);
   const verbose = valid.bool(1, false);
-  const out = [];
-
-  if (help || args.length < 1 || args.length > 2)
-    throw new RPCError(errs.MISC_ERROR, 'getmempooldescendants txid (verbose)');
 
   if (!this.mempool)
     throw new RPCError(errs.MISC_ERROR, 'No mempool available.');
@@ -742,6 +743,7 @@ RPC.prototype.getMempoolDescendants = async function getMempoolDescendants(args,
     throw new RPCError(errs.MISC_ERROR, 'Transaction not in mempool.');
 
   const entries = this.mempool.getDescendants(entry);
+  const out = [];
 
   if (verbose) {
     for (const entry of entries)
@@ -755,12 +757,12 @@ RPC.prototype.getMempoolDescendants = async function getMempoolDescendants(args,
 };
 
 RPC.prototype.getMempoolEntry = async function getMempoolEntry(args, help) {
-  const valid = new Validator([args]);
-  const hash = valid.hash(0);
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'getmempoolentry txid');
 
+  const valid = new Validator([args]);
+  const hash = valid.hash(0);
+
   if (!this.mempool)
     throw new RPCError(errs.MISC_ERROR, 'No mempool available.');
 
@@ -776,17 +778,18 @@ RPC.prototype.getMempoolEntry = async function getMempoolEntry(args, help) {
 };
 
 RPC.prototype.getRawMempool = async function getRawMempool(args, help) {
-  const valid = new Validator([args]);
-  const verbose = valid.bool(0, false);
-  const out = {};
-
   if (help || args.length > 1)
     throw new RPCError(errs.MISC_ERROR, 'getrawmempool ( verbose )');
 
+  const valid = new Validator([args]);
+  const verbose = valid.bool(0, false);
+
   if (!this.mempool)
     throw new RPCError(errs.MISC_ERROR, 'No mempool available.');
 
   if (verbose) {
+    const out = {};
+
     for (const entry of this.mempool.map.values())
       out[entry.txid()] = this.entryToJSON(entry);
 
@@ -799,14 +802,13 @@ RPC.prototype.getRawMempool = async function getRawMempool(args, help) {
 };
 
 RPC.prototype.getTXOut = async function getTXOut(args, help) {
+  if (help || args.length < 2 || args.length > 3)
+    throw new RPCError(errs.MISC_ERROR, 'gettxout "txid" n ( includemempool )');
+
   const valid = new Validator([args]);
   const hash = valid.hash(0);
   const index = valid.u32(1);
   const mempool = valid.bool(2, true);
-  let coin;
-
-  if (help || args.length < 2 || args.length > 3)
-    throw new RPCError(errs.MISC_ERROR, 'gettxout "txid" n ( includemempool )');
 
   if (this.chain.options.spv)
     throw new RPCError(errs.MISC_ERROR, 'Cannot get coins in SPV mode.');
@@ -817,6 +819,7 @@ RPC.prototype.getTXOut = async function getTXOut(args, help) {
   if (!hash || index == null)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid outpoint.');
 
+  let coin;
   if (mempool) {
     if (!this.mempool)
       throw new RPCError(errs.MISC_ERROR, 'No mempool available.');
@@ -840,16 +843,15 @@ RPC.prototype.getTXOut = async function getTXOut(args, help) {
 };
 
 RPC.prototype.getTXOutProof = async function getTXOutProof(args, help) {
-  const valid = new Validator([args]);
-  const txids = valid.array(0);
-  const hash = valid.hash(1);
-  const uniq = new Set();
-
   if (help || (args.length !== 1 && args.length !== 2)) {
     throw new RPCError(errs.MISC_ERROR,
       'gettxoutproof ["txid",...] ( blockhash )');
   }
 
+  const valid = new Validator([args]);
+  const txids = valid.array(0);
+  const hash = valid.hash(1);
+
   if (this.chain.options.spv)
     throw new RPCError(errs.MISC_ERROR, 'Cannot get coins in SPV mode.');
 
@@ -860,8 +862,8 @@ RPC.prototype.getTXOutProof = async function getTXOutProof(args, help) {
     throw new RPCError(errs.INVALID_PARAMETER, 'Invalid TXIDs.');
 
   const items = new Validator([txids]);
-  let last = null;
-  let block = null;
+  const uniq = new Set();
+  let last, block;
 
   for (let i = 0; i < txids.length; i++) {
     const txid = items.hash(i);
@@ -881,14 +883,12 @@ RPC.prototype.getTXOutProof = async function getTXOutProof(args, help) {
     block = await this.chain.db.getBlock(hash);
   } else if (this.chain.options.indexTX) {
     const tx = await this.chain.db.getMeta(last);
-    if (!tx)
-      return;
-    block = await this.chain.db.getBlock(tx.block);
+    if (tx)
+      block = await this.chain.db.getBlock(tx.block);
   } else {
     const coins = await this.chain.db.getCoins(last);
-    if (!coins)
-      return;
-    block = await this.chain.db.getBlock(coins.height);
+    if (coins)
+      block = await this.chain.db.getBlock(coins.height);
   }
 
   if (!block)
@@ -907,20 +907,19 @@ RPC.prototype.getTXOutProof = async function getTXOutProof(args, help) {
 };
 
 RPC.prototype.verifyTXOutProof = async function verifyTXOutProof(args, help) {
-  const valid = new Validator([args]);
-  const data = valid.buf(0);
-  const out = [];
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'verifytxoutproof "proof"');
 
+  const valid = new Validator([args]);
+  const data = valid.buf(0);
+
   if (!data)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid hex string.');
 
   const block = MerkleBlock.fromRaw(data);
 
   if (!block.verify())
-    return out;
+    return [];
 
   const entry = await this.chain.db.getEntry(block.hash('hex'));
 
@@ -928,6 +927,7 @@ RPC.prototype.verifyTXOutProof = async function verifyTXOutProof(args, help) {
     throw new RPCError(errs.MISC_ERROR, 'Block not found in chain.');
 
   const tree = block.getTree();
+  const out = [];
 
   for (const hash of tree.matches)
     out.push(util.revHex(hash));
@@ -974,13 +974,13 @@ RPC.prototype.pruneBlockchain = async function pruneBlockchain(args, help) {
 };
 
 RPC.prototype.verifyChain = async function verifyChain(args, help) {
+  if (help || args.length > 2)
+    throw new RPCError(errs.MISC_ERROR, 'verifychain ( checklevel numblocks )');
+
   const valid = new Validator([args]);
   const level = valid.u32(0);
   const blocks = valid.u32(1);
 
-  if (help || args.length > 2)
-    throw new RPCError(errs.MISC_ERROR, 'verifychain ( checklevel numblocks )');
-
   if (level == null || blocks == null)
     throw new RPCError(errs.TYPE_ERROR, 'Missing parameters.');
 
@@ -1043,8 +1043,8 @@ RPC.prototype._submitWork = async function _submitWork(data) {
     return false;
 
   const block = attempt.commit(proof);
-  let entry = null;
 
+  let entry;
   try {
     entry = await this.chain.add(block);
   } catch (err) {
@@ -1106,13 +1106,13 @@ RPC.prototype.getWorkLongpoll = async function getWorkLongpoll(args, help) {
 };
 
 RPC.prototype.getWork = async function getWork(args, help) {
-  const valid = new Validator([args]);
-  const data = valid.buf(0);
-
   if (args.length > 1)
     throw new RPCError(errs.MISC_ERROR, 'getwork ( "data" )');
 
   if (args.length === 1) {
+    const valid = new Validator([args]);
+    const data = valid.buf(0);
+
     if (!data)
       throw new RPCError(errs.TYPE_ERROR, 'Invalid work data.');
 
@@ -1123,42 +1123,36 @@ RPC.prototype.getWork = async function getWork(args, help) {
 };
 
 RPC.prototype.submitBlock = async function submitBlock(args, help) {
-  const valid = new Validator([args]);
-  const data = valid.buf(0);
-
   if (help || args.length < 1 || args.length > 2) {
     throw new RPCError(errs.MISC_ERROR,
       'submitblock "hexdata" ( "jsonparametersobject" )');
   }
 
+  const valid = new Validator([args]);
+  const data = valid.buf(0);
+
   const block = Block.fromRaw(data);
 
   return await this.addBlock(block);
 };
 
 RPC.prototype.getBlockTemplate = async function getBlockTemplate(args, help) {
-  const validator = new Validator([args]);
-  const options = validator.obj(0, {});
-  const valid = new Validator([options]);
-  const mode = valid.str('mode', 'template');
-  const lpid = valid.str('longpollid');
-  const data = valid.buf('data');
-  let rules = valid.array('rules');
-  const capabilities = valid.array('capabilities');
-  let maxVersion = valid.u32('maxversion', -1);
-  let coinbase = false;
-  let txnCap = false;
-  let valueCap = false;
-
   if (help || args.length > 1) {
     throw new RPCError(errs.MISC_ERROR,
       'getblocktemplate ( "jsonrequestobject" )');
   }
 
+  const validator = new Validator([args]);
+  const options = validator.obj(0, {});
+  const valid = new Validator([options]);
+  const mode = valid.str('mode', 'template');
+
   if (mode !== 'template' && mode !== 'proposal')
     throw new RPCError(errs.INVALID_PARAMETER, 'Invalid mode.');
 
   if (mode === 'proposal') {
+    const data = valid.buf('data');
+
     if (!data)
       throw new RPCError(errs.TYPE_ERROR, 'Missing data parameter.');
 
@@ -1178,10 +1172,19 @@ RPC.prototype.getBlockTemplate = async function getBlockTemplate(args, help) {
     return null;
   }
 
+  let maxVersion = valid.u32('maxversion', -1);
+  let rules = valid.array('rules');
+
   if (rules)
     maxVersion = -1;
 
+  const capabilities = valid.array('capabilities');
+  let coinbase = false;
+
   if (capabilities) {
+    let txnCap = false;
+    let valueCap = false;
+
     for (const capability of capabilities) {
       if (typeof capability !== 'string')
         throw new RPCError(errs.TYPE_ERROR, 'Invalid capability.');
@@ -1228,6 +1231,8 @@ RPC.prototype.getBlockTemplate = async function getBlockTemplate(args, help) {
     }
   }
 
+  const lpid = valid.str('longpollid');
+
   if (lpid)
     await this.handleLongpoll(lpid);
 
@@ -1248,13 +1253,10 @@ RPC.prototype.createTemplate = async function createTemplate(maxVersion, coinbas
 
 RPC.prototype._createTemplate = async function _createTemplate(maxVersion, coinbase, rules) {
   const attempt = await this.getTemplate();
-  let version = attempt.version;
   const scale = attempt.witness ? 1 : consensus.WITNESS_SCALE_FACTOR;
+
+  // Default mutable fields.
   const mutable = ['time', 'transactions', 'prevblock'];
-  const txs = [];
-  const index = new Map();
-  const vbavailable = {};
-  const vbrules = [];
 
   // The miner doesn't support
   // versionbits. Force them to
@@ -1273,12 +1275,14 @@ RPC.prototype._createTemplate = async function _createTemplate(maxVersion, coinb
   }
 
   // Build an index of every transaction.
+  const index = new Map();
   for (let i = 0; i < attempt.items.length; i++) {
     const entry = attempt.items[i];
     index.set(entry.hash, i + 1);
   }
 
   // Calculate dependencies for each transaction.
+  const txs = [];
   for (let i = 0; i < attempt.items.length; i++) {
     const entry = attempt.items[i];
     const tx = entry.tx;
@@ -1317,6 +1321,10 @@ RPC.prototype._createTemplate = async function _createTemplate(maxVersion, coinb
     rules.push('segwit');
 
   // Calculate version based on given rules.
+  let version = attempt.version;
+  const vbavailable = {};
+  const vbrules = [];
+
   for (const deploy of this.network.deploys) {
     const state = await this.chain.getState(this.chain.tip, deploy);
     let name = deploy.name;
@@ -1433,15 +1441,16 @@ RPC.prototype._createTemplate = async function _createTemplate(maxVersion, coinb
 };
 
 RPC.prototype.getMiningInfo = async function getMiningInfo(args, help) {
+  if (help || args.length !== 0)
+    throw new RPCError(errs.MISC_ERROR, 'getmininginfo');
+
   const attempt = this.attempt;
+
   let size = 0;
   let weight = 0;
   let txs = 0;
   let diff = 0;
 
-  if (help || args.length !== 0)
-    throw new RPCError(errs.MISC_ERROR, 'getmininginfo');
-
   if (attempt) {
     weight = attempt.weight;
     txs = attempt.items.length + 1;
@@ -1470,27 +1479,27 @@ RPC.prototype.getMiningInfo = async function getMiningInfo(args, help) {
 };
 
 RPC.prototype.getNetworkHashPS = async function getNetworkHashPS(args, help) {
+  if (help || args.length > 2)
+    throw new RPCError(errs.MISC_ERROR, 'getnetworkhashps ( blocks height )');
+
   const valid = new Validator([args]);
   const lookup = valid.u32(0, 120);
   const height = valid.u32(1);
 
-  if (help || args.length > 2)
-    throw new RPCError(errs.MISC_ERROR, 'getnetworkhashps ( blocks height )');
-
   return await this.getHashRate(lookup, height);
 };
 
 RPC.prototype.prioritiseTransaction = async function prioritiseTransaction(args, help) {
-  const valid = new Validator([args]);
-  const hash = valid.hash(0);
-  const pri = valid.num(1);
-  const fee = valid.i64(2);
-
   if (help || args.length !== 3) {
     throw new RPCError(errs.MISC_ERROR,
       'prioritisetransaction <txid> <priority delta> <fee delta>');
   }
 
+  const valid = new Validator([args]);
+  const hash = valid.hash(0);
+  const pri = valid.num(1);
+  const fee = valid.i64(2);
+
   if (!this.mempool)
     throw new RPCError(errs.MISC_ERROR, 'No mempool available.');
 
@@ -1511,12 +1520,12 @@ RPC.prototype.prioritiseTransaction = async function prioritiseTransaction(args,
 };
 
 RPC.prototype.verifyBlock = async function verifyBlock(args, help) {
-  const valid = new Validator([args]);
-  const data = valid.buf(0);
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'verifyblock "block-hex"');
 
+  const valid = new Validator([args]);
+  const data = valid.buf(0);
+
   if (!data)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid block hex.');
 
@@ -1547,13 +1556,13 @@ RPC.prototype.getGenerate = async function getGenerate(args, help) {
 };
 
 RPC.prototype.setGenerate = async function setGenerate(args, help) {
+  if (help || args.length < 1 || args.length > 2)
+    throw new RPCError(errs.MISC_ERROR, 'setgenerate mine ( proclimit )');
+
   const valid = new Validator([args]);
   const mine = valid.bool(0, false);
   const limit = valid.u32(1, 0);
 
-  if (help || args.length < 1 || args.length > 2)
-    throw new RPCError(errs.MISC_ERROR, 'setgenerate mine ( proclimit )');
-
   if (mine && this.miner.addresses.length === 0) {
     throw new RPCError(errs.MISC_ERROR,
       'No addresses available for coinbase.');
@@ -1573,13 +1582,13 @@ RPC.prototype.setGenerate = async function setGenerate(args, help) {
 };
 
 RPC.prototype.generate = async function generate(args, help) {
+  if (help || args.length < 1 || args.length > 2)
+    throw new RPCError(errs.MISC_ERROR, 'generate numblocks ( maxtries )');
+
   const valid = new Validator([args]);
   const blocks = valid.u32(0, 1);
   const tries = valid.u32(1);
 
-  if (help || args.length < 1 || args.length > 2)
-    throw new RPCError(errs.MISC_ERROR, 'generate numblocks ( maxtries )');
-
   if (this.miner.addresses.length === 0) {
     throw new RPCError(errs.MISC_ERROR,
       'No addresses available for coinbase.');
@@ -1589,16 +1598,16 @@ RPC.prototype.generate = async function generate(args, help) {
 };
 
 RPC.prototype.generateToAddress = async function _generateToAddress(args, help) {
-  const valid = new Validator([args]);
-  const blocks = valid.u32(0, 1);
-  const str = valid.str(1, '');
-  const tries = valid.u32(2);
-
   if (help || args.length < 2 || args.length > 3) {
     throw new RPCError(errs.MISC_ERROR,
       'generatetoaddress numblocks address ( maxtries )');
   }
 
+  const valid = new Validator([args]);
+  const blocks = valid.u32(0, 1);
+  const str = valid.str(1, '');
+  const tries = valid.u32(2);
+
   const addr = parseAddress(str, this.network);
 
   return await this.mineBlocks(blocks, addr, tries);
@@ -1609,12 +1618,6 @@ RPC.prototype.generateToAddress = async function _generateToAddress(args, help)
  */
 
 RPC.prototype.createRawTransaction = async function createRawTransaction(args, help) {
-  const valid = new Validator([args]);
-  const inputs = valid.array(0);
-  const sendTo = valid.obj(1);
-  const locktime = valid.u32(2);
-  const uniq = new Set();
-
   if (help || args.length < 2 || args.length > 3) {
     throw new RPCError(errs.MISC_ERROR,
       'createrawtransaction'
@@ -1623,6 +1626,11 @@ RPC.prototype.createRawTransaction = async function createRawTransaction(args, h
       + ' ( locktime )');
   }
 
+  const valid = new Validator([args]);
+  const inputs = valid.array(0);
+  const sendTo = valid.obj(1);
+  const locktime = valid.u32(2);
+
   if (!inputs || !sendTo) {
     throw new RPCError(errs.TYPE_ERROR,
       'Invalid parameters (inputs and sendTo).');
@@ -1654,6 +1662,7 @@ RPC.prototype.createRawTransaction = async function createRawTransaction(args, h
   }
 
   const sends = new Validator([sendTo]);
+  const uniq = new Set();
 
   for (const key of Object.keys(sendTo)) {
     if (key === 'data') {
@@ -1694,12 +1703,12 @@ RPC.prototype.createRawTransaction = async function createRawTransaction(args, h
 };
 
 RPC.prototype.decodeRawTransaction = async function decodeRawTransaction(args, help) {
-  const valid = new Validator([args]);
-  const data = valid.buf(0);
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'decoderawtransaction "hexstring"');
 
+  const valid = new Validator([args]);
+  const data = valid.buf(0);
+
   if (!data)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid hex string.');
 
@@ -1709,12 +1718,12 @@ RPC.prototype.decodeRawTransaction = async function decodeRawTransaction(args, h
 };
 
 RPC.prototype.decodeScript = async function decodeScript(args, help) {
-  const valid = new Validator([args]);
-  const data = valid.buf(0);
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'decodescript "hex"');
 
+  const valid = new Validator([args]);
+  const data = valid.buf(0);
+
   let script = new Script();
 
   if (data)
@@ -1729,13 +1738,13 @@ RPC.prototype.decodeScript = async function decodeScript(args, help) {
 };
 
 RPC.prototype.getRawTransaction = async function getRawTransaction(args, help) {
+  if (help || args.length < 1 || args.length > 2)
+    throw new RPCError(errs.MISC_ERROR, 'getrawtransaction "txid" ( verbose )');
+
   const valid = new Validator([args]);
   const hash = valid.hash(0);
   const verbose = valid.bool(1, false);
 
-  if (help || args.length < 1 || args.length > 2)
-    throw new RPCError(errs.MISC_ERROR, 'getrawtransaction "txid" ( verbose )');
-
   if (!hash)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid TXID.');
 
@@ -1749,8 +1758,7 @@ RPC.prototype.getRawTransaction = async function getRawTransaction(args, help) {
   if (!verbose)
     return tx.toRaw().toString('hex');
 
-  let entry = null;
-
+  let entry;
   if (meta.block)
     entry = await this.chain.db.getEntry(meta.block);
 
@@ -1762,14 +1770,14 @@ RPC.prototype.getRawTransaction = async function getRawTransaction(args, help) {
 };
 
 RPC.prototype.sendRawTransaction = async function sendRawTransaction(args, help) {
-  const valid = new Validator([args]);
-  const data = valid.buf(0);
-
   if (help || args.length < 1 || args.length > 2) {
     throw new RPCError(errs.MISC_ERROR,
       'sendrawtransaction "hexstring" ( allowhighfees )');
   }
 
+  const valid = new Validator([args]);
+  const data = valid.buf(0);
+
   if (!data)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid hex string.');
 
@@ -1781,15 +1789,6 @@ RPC.prototype.sendRawTransaction = async function sendRawTransaction(args, help)
 };
 
 RPC.prototype.signRawTransaction = async function signRawTransaction(args, help) {
-  const valid = new Validator([args]);
-  const data = valid.buf(0);
-  const prevout = valid.array(1);
-  const secrets = valid.array(2);
-  const sighash = valid.str(3);
-  const type = Script.hashType.ALL;
-  const map = new Map();
-  const keys = [];
-
   if (help || args.length < 1 || args.length > 4) {
     throw new RPCError(errs.MISC_ERROR,
       'signrawtransaction'
@@ -1799,6 +1798,12 @@ RPC.prototype.signRawTransaction = async function signRawTransaction(args, help)
       + ' sighashtype )');
   }
 
+  const valid = new Validator([args]);
+  const data = valid.buf(0);
+  const prevout = valid.array(1);
+  const secrets = valid.array(2);
+  const sighash = valid.str(3);
+
   if (!data)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid hex string.');
 
@@ -1808,6 +1813,9 @@ RPC.prototype.signRawTransaction = async function signRawTransaction(args, help)
   const tx = MTX.fromRaw(data);
   tx.view = await this.mempool.getSpentView(tx);
 
+  const map = new Map();
+  const keys = [];
+
   if (secrets) {
     const valid = new Validator([secrets]);
     for (let i = 0; i < secrets.length; i++) {
@@ -1823,33 +1831,32 @@ RPC.prototype.signRawTransaction = async function signRawTransaction(args, help)
       const valid = new Validator([prev]);
       const hash = valid.hash('txid');
       const index = valid.u32('index');
-      let script = valid.buf('scriptPubKey');
+      const scriptRaw = valid.buf('scriptPubKey');
       const value = valid.btc('amount');
-      let redeem = valid.buf('redeemScript');
+      const redeemRaw = valid.buf('redeemScript');
 
-      if (!hash || index == null || !script || value == null)
+      if (!hash || index == null || !scriptRaw || value == null)
         throw new RPCError(errs.INVALID_PARAMETER, 'Invalid UTXO.');
 
-      script = Script.fromRaw(script);
+      const outpoint = new Outpoint(hash, index);
 
-      const coin = new Output();
-      coin.script = script;
-      coin.value = value;
+      const script = Script.fromRaw(scriptRaw);
+      const coin = Output.fromScript(script, value);
 
-      tx.view.addOutput(hash, index, coin);
+      tx.view.addOutput(outpoint, coin);
 
-      if (keys.length === 0 || !redeem)
+      if (keys.length === 0 || !redeemRaw)
         continue;
 
       if (!script.isScripthash() && !script.isWitnessScripthash())
         continue;
 
-      if (!redeem) {
+      if (!redeemRaw) {
         throw new RPCError(errs.INVALID_PARAMETER,
           'P2SH requires redeem script.');
       }
 
-      redeem = Script.fromRaw(redeem);
+      const redeem = Script.fromRaw(redeemRaw);
 
       for (const op of redeem.code) {
         if (!op.data)
@@ -1867,14 +1874,16 @@ RPC.prototype.signRawTransaction = async function signRawTransaction(args, help)
     }
   }
 
+  let type = Script.hashType.ALL;
   if (sighash) {
     const parts = sighash.split('|');
-    let type = Script.hashType[parts[0]];
 
-    if (type == null)
+    if (parts.length < 1 || parts.length > 2)
       throw new RPCError(errs.INVALID_PARAMETER, 'Invalid sighash type.');
 
-    if (parts.length > 2)
+    type = Script.hashType[parts[0]];
+
+    if (type == null)
       throw new RPCError(errs.INVALID_PARAMETER, 'Invalid sighash type.');
 
     if (parts.length === 2) {
@@ -1897,14 +1906,14 @@ RPC.prototype.signRawTransaction = async function signRawTransaction(args, help)
  */
 
 RPC.prototype.createMultisig = async function createMultisig(args, help) {
+  if (help || args.length < 2 || args.length > 2)
+    throw new RPCError(errs.MISC_ERROR, 'createmultisig nrequired ["key",...]');
+
   const valid = new Validator([args]);
   const keys = valid.array(1, []);
   const m = valid.u32(0, 0);
   const n = keys.length;
 
-  if (help || args.length < 2 || args.length > 2)
-    throw new RPCError(errs.MISC_ERROR, 'createmultisig nrequired ["key",...]');
-
   if (m < 1 || n < m || n > 16)
     throw new RPCError(errs.INVALID_PARAMETER, 'Invalid m and n values.');
 
@@ -1936,12 +1945,12 @@ RPC.prototype.createMultisig = async function createMultisig(args, help) {
 };
 
 RPC.prototype.createWitnessAddress = async function createWitnessAddress(args, help) {
-  const valid = new Validator([args]);
-  const raw = valid.buf(0);
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'createwitnessaddress "script"');
 
+  const valid = new Validator([args]);
+  const raw = valid.buf(0);
+
   if (!raw)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid script hex.');
 
@@ -1956,13 +1965,13 @@ RPC.prototype.createWitnessAddress = async function createWitnessAddress(args, h
 };
 
 RPC.prototype.validateAddress = async function validateAddress(args, help) {
-  const valid = new Validator([args]);
-  const str = valid.str(0, '');
-  let addr;
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'validateaddress "bitcoinaddress"');
 
+  const valid = new Validator([args]);
+  const str = valid.str(0, '');
+
+  let addr;
   try {
     addr = Address.fromString(str, this.network);
   } catch (e) {
@@ -1983,16 +1992,16 @@ RPC.prototype.validateAddress = async function validateAddress(args, help) {
 };
 
 RPC.prototype.verifyMessage = async function verifyMessage(args, help) {
-  const valid = new Validator([args]);
-  const b58 = valid.str(0, '');
-  const sig = valid.buf(1, null, 'base64');
-  const str = valid.str(2);
-
   if (help || args.length !== 3) {
     throw new RPCError(errs.MISC_ERROR,
       'verifymessage "bitcoinaddress" "signature" "message"');
   }
 
+  const valid = new Validator([args]);
+  const b58 = valid.str(0, '');
+  const sig = valid.buf(1, null, 'base64');
+  const str = valid.str(2);
+
   if (!sig || !str)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid parameters.');
 
@@ -2009,15 +2018,15 @@ RPC.prototype.verifyMessage = async function verifyMessage(args, help) {
 };
 
 RPC.prototype.signMessageWithPrivkey = async function signMessageWithPrivkey(args, help) {
-  const valid = new Validator([args]);
-  const wif = valid.str(0, '');
-  const str = valid.str(1, '');
-
   if (help || args.length !== 2) {
     throw new RPCError(errs.MISC_ERROR,
       'signmessagewithprivkey "privkey" "message"');
   }
 
+  const valid = new Validator([args]);
+  const wif = valid.str(0, '');
+  const str = valid.str(1, '');
+
   const key = parseSecret(wif, this.network);
   const msg = Buffer.from(MAGIC_STRING + str, 'utf8');
   const hash = digest.hash256(msg);
@@ -2027,18 +2036,15 @@ RPC.prototype.signMessageWithPrivkey = async function signMessageWithPrivkey(arg
 };
 
 RPC.prototype.estimateFee = async function estimateFee(args, help) {
-  const valid = new Validator([args]);
-  let blocks = valid.u32(0, 1);
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'estimatefee nblocks');
 
+  const valid = new Validator([args]);
+  const blocks = valid.u32(0, 1);
+
   if (!this.fees)
     throw new RPCError(errs.MISC_ERROR, 'Fee estimation not available.');
 
-  if (blocks < 1)
-    blocks = 1;
-
   const fee = this.fees.estimateFee(blocks, false);
 
   if (fee === 0)
@@ -2048,34 +2054,28 @@ RPC.prototype.estimateFee = async function estimateFee(args, help) {
 };
 
 RPC.prototype.estimatePriority = async function estimatePriority(args, help) {
-  const valid = new Validator([args]);
-  let blocks = valid.u32(0, 1);
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'estimatepriority nblocks');
 
+  const valid = new Validator([args]);
+  const blocks = valid.u32(0, 1);
+
   if (!this.fees)
     throw new RPCError(errs.MISC_ERROR, 'Priority estimation not available.');
 
-  if (blocks < 1)
-    blocks = 1;
-
   return this.fees.estimatePriority(blocks, false);
 };
 
 RPC.prototype.estimateSmartFee = async function estimateSmartFee(args, help) {
-  const valid = new Validator([args]);
-  let blocks = valid.u32(0, 1);
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'estimatesmartfee nblocks');
 
+  const valid = new Validator([args]);
+  const blocks = valid.u32(0, 1);
+
   if (!this.fees)
     throw new RPCError(errs.MISC_ERROR, 'Fee estimation not available.');
 
-  if (blocks < 1)
-    blocks = 1;
-
   let fee = this.fees.estimateFee(blocks, true);
 
   if (fee === 0)
@@ -2090,18 +2090,15 @@ RPC.prototype.estimateSmartFee = async function estimateSmartFee(args, help) {
 };
 
 RPC.prototype.estimateSmartPriority = async function estimateSmartPriority(args, help) {
-  const valid = new Validator([args]);
-  let blocks = valid.u32(0, 1);
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'estimatesmartpriority nblocks');
 
+  const valid = new Validator([args]);
+  const blocks = valid.u32(0, 1);
+
   if (!this.fees)
     throw new RPCError(errs.MISC_ERROR, 'Priority estimation not available.');
 
-  if (blocks < 1)
-    blocks = 1;
-
   const pri = this.fees.estimatePriority(blocks, true);
 
   return {
@@ -2111,12 +2108,12 @@ RPC.prototype.estimateSmartPriority = async function estimateSmartPriority(args,
 };
 
 RPC.prototype.invalidateBlock = async function invalidateBlock(args, help) {
-  const valid = new Validator([args]);
-  const hash = valid.hash(0);
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'invalidateblock "hash"');
 
+  const valid = new Validator([args]);
+  const hash = valid.hash(0);
+
   if (!hash)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid block hash.');
 
@@ -2126,12 +2123,12 @@ RPC.prototype.invalidateBlock = async function invalidateBlock(args, help) {
 };
 
 RPC.prototype.reconsiderBlock = async function reconsiderBlock(args, help) {
-  const valid = new Validator([args]);
-  const hash = valid.hash(0);
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'reconsiderblock "hash"');
 
+  const valid = new Validator([args]);
+  const hash = valid.hash(0);
+
   if (!hash)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid block hash.');
 
@@ -2141,12 +2138,12 @@ RPC.prototype.reconsiderBlock = async function reconsiderBlock(args, help) {
 };
 
 RPC.prototype.setMockTime = async function setMockTime(args, help) {
-  const valid = new Validator([args]);
-  const time = valid.u32(0);
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'setmocktime timestamp');
 
+  const valid = new Validator([args]);
+  const time = valid.u32(0);
+
   if (time == null)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid timestamp.');
 
@@ -2167,12 +2164,12 @@ RPC.prototype.getMemoryInfo = async function getMemoryInfo(args, help) {
 };
 
 RPC.prototype.setLogLevel = async function setLogLevel(args, help) {
-  const valid = new Validator([args]);
-  const level = valid.str(0, '');
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'setloglevel "level"');
 
+  const valid = new Validator([args]);
+  const level = valid.str(0, '');
+
   this.logger.setLevel(level);
 
   return null;
@@ -2246,10 +2243,10 @@ RPC.prototype.bindChain = function bindChain() {
 };
 
 RPC.prototype.getTemplate = async function getTemplate() {
-  let attempt = this.attempt;
-
   this.bindChain();
 
+  let attempt = this.attempt;
+
   if (attempt) {
     this.miner.updateTime(attempt);
   } else {
@@ -2262,10 +2259,10 @@ RPC.prototype.getTemplate = async function getTemplate() {
 };
 
 RPC.prototype.updateWork = async function updateWork() {
-  let attempt = this.attempt;
-
   this.bindChain();
 
+  let attempt = this.attempt;
+
   if (attempt) {
     if (attempt.address.isNull()) {
       throw new RPCError(errs.MISC_ERROR,
@@ -2346,8 +2343,7 @@ RPC.prototype._addBlock = async function _addBlock(block) {
     }
   }
 
-  let entry = null;
-
+  let entry;
   try {
     entry = await this.chain._add(block);
   } catch (err) {
@@ -2386,7 +2382,7 @@ RPC.prototype.getBIP9Softforks = async function getBIP9Softforks() {
 
   for (const deployment of this.network.deploys) {
     const state = await this.chain.getState(tip, deployment);
-    let status = null;
+    let status;
 
     switch (state) {
       case common.thresholdStates.DEFINED:
@@ -2437,23 +2433,22 @@ RPC.prototype.getHashRate = async function getHashRate(lookup, height) {
 
   let minTime = tip.time;
   let maxTime = minTime;
-  let last = tip;
+  let entry = tip;
 
   for (let i = 0; i < lookup; i++) {
-    const entry = await entry.getPrevious();
+    entry = await entry.getPrevious();
 
     if (!entry)
       throw new RPCError(errs.DATABASE_ERROR, 'Not found.');
 
     minTime = Math.min(entry.time, minTime);
     maxTime = Math.max(entry.time, maxTime);
-    last = entry;
   }
 
   if (minTime === maxTime)
     return 0;
 
-  const workDiff = tip.chainwork.sub(last.chainwork);
+  const workDiff = tip.chainwork.sub(entry.chainwork);
   const timeDiff = maxTime - minTime;
   const ps = +workDiff.toString(10) / timeDiff;
 
@@ -2492,11 +2487,9 @@ RPC.prototype.findFork = async function findFork(entry) {
 
 RPC.prototype.txToJSON = function txToJSON(tx, entry) {
   let height = -1;
-  let conf = 0;
   let time = 0;
   let hash = null;
-  const vin = [];
-  const vout = [];
+  let conf = 0;
 
   if (entry) {
     height = entry.height;
@@ -2505,6 +2498,8 @@ RPC.prototype.txToJSON = function txToJSON(tx, entry) {
     conf = this.chain.height - height + 1;
   }
 
+  const vin = [];
+
   for (const input of tx.inputs) {
     const json = {
       coinbase: undefined,
@@ -2534,6 +2529,8 @@ RPC.prototype.txToJSON = function txToJSON(tx, entry) {
     vin.push(json);
   }
 
+  const vout = [];
+
   for (let i = 0; i < tx.outputs.length; i++) {
     const output = tx.outputs[i];
     vout.push({
@@ -2562,7 +2559,6 @@ RPC.prototype.txToJSON = function txToJSON(tx, entry) {
 
 RPC.prototype.scriptToJSON = function scriptToJSON(script, hex) {
   const type = script.getType();
-  const addr = script.getAddress();
 
   const json = {
     asm: script.toASM(),
@@ -2579,6 +2575,8 @@ RPC.prototype.scriptToJSON = function scriptToJSON(script, hex) {
   if (script.isMultisig())
     json.reqSigs = script.getSmall(0);
 
+  const addr = script.getAddress();
+
   if (addr) {
     const str = addr.toString(this.network);
     json.addresses.push(str);
diff --git a/lib/http/rpcbase.js b/lib/http/rpcbase.js
index f618fa12..987924b5 100644
--- a/lib/http/rpcbase.js
+++ b/lib/http/rpcbase.js
@@ -112,8 +112,6 @@ RPCBase.prototype.call = async function call(body, query) {
   }
 
   for (const cmd of cmds) {
-    let result;
-
     if (!cmd || typeof cmd !== 'object') {
       out.push({
         result: null,
@@ -183,6 +181,7 @@ RPCBase.prototype.call = async function call(body, query) {
         cmd.method = 'getworklp';
     }
 
+    let result;
     try {
       result = await this.execute(cmd);
     } catch (err) {
diff --git a/lib/http/server.js b/lib/http/server.js
index cc47fc06..f8c6b589 100644
--- a/lib/http/server.js
+++ b/lib/http/server.js
@@ -143,12 +143,12 @@ HTTPServer.prototype.initRouter = function initRouter() {
   this.get('/coin/address/:address', async (req, res) => {
     const valid = req.valid();
     const address = valid.str('address');
-    const result = [];
 
     enforce(address, 'Address is required.');
     enforce(!this.chain.options.spv, 'Cannot get coins in SPV mode.');
 
     const coins = await this.node.getCoinsByAddress(address);
+    const result = [];
 
     for (const coin of coins)
       result.push(coin.getJSON(this.network));
@@ -180,12 +180,12 @@ HTTPServer.prototype.initRouter = function initRouter() {
   this.post('/coin/address', async (req, res) => {
     const valid = req.valid();
     const address = valid.array('addresses');
-    const result = [];
 
     enforce(address, 'Address is required.');
     enforce(!this.chain.options.spv, 'Cannot get coins in SPV mode.');
 
     const coins = await this.node.getCoinsByAddress(address);
+    const result = [];
 
     for (const coin of coins)
       result.push(coin.getJSON(this.network));
@@ -217,12 +217,12 @@ HTTPServer.prototype.initRouter = function initRouter() {
   this.get('/tx/address/:address', async (req, res) => {
     const valid = req.valid();
     const address = valid.str('address');
-    const result = [];
 
     enforce(address, 'Address is required.');
     enforce(!this.chain.options.spv, 'Cannot get TX in SPV mode.');
 
     const metas = await this.node.getMetaByAddress(address);
+    const result = [];
 
     for (const meta of metas) {
       const view = await this.node.getMetaView(meta);
@@ -236,12 +236,12 @@ HTTPServer.prototype.initRouter = function initRouter() {
   this.post('/tx/address', async (req, res) => {
     const valid = req.valid();
     const address = valid.array('address');
-    const result = [];
 
     enforce(address, 'Address is required.');
     enforce(!this.chain.options.spv, 'Cannot get TX in SPV mode.');
 
     const metas = await this.node.getMetaByAddress(address);
+    const result = [];
 
     for (const meta of metas) {
       const view = await this.node.getMetaView(meta);
@@ -285,11 +285,10 @@ HTTPServer.prototype.initRouter = function initRouter() {
 
   // Mempool snapshot
   this.get('/mempool', async (req, res) => {
-    const result = [];
-
     enforce(this.mempool, 'No mempool available.');
 
     const hashes = this.mempool.getSnapshot();
+    const result = [];
 
     for (const hash of hashes)
       result.push(util.revHex(hash));
@@ -361,16 +360,21 @@ HTTPServer.prototype.initSockets = function initSockets() {
 
 HTTPServer.prototype.handleSocket = function handleSocket(socket) {
   socket.hook('auth', (args) => {
-    const valid = new Validator([args]);
-    const hash = this.options.apiHash;
-    const key = valid.str(0);
-
     if (socket.auth)
       throw new Error('Already authed.');
 
     if (!this.options.noAuth) {
-      if (!ccmp(hash256(key), hash))
-        throw new Error('Bad key.');
+      const valid = new Validator([args]);
+      const key = valid.str(0, '');
+
+      if (key.length > 255)
+        throw new Error('Invalid API key.');
+
+      const data = Buffer.from(key, 'utf8');
+      const hash = digest.hash256(data);
+
+      if (!ccmp(hash, this.options.apiHash))
+        throw new Error('Invalid API key.');
     }
 
     socket.auth = true;
@@ -593,10 +597,10 @@ HTTPServer.prototype.bindChain = function bindChain() {
  */
 
 HTTPServer.prototype.filterBlock = function filterBlock(socket, block) {
-  const txs = [];
-
   if (!socket.filter)
-    return txs;
+    return [];
+
+  const txs = [];
 
   for (const tx of block.txs) {
     if (this.filterTX(socket, tx))
@@ -615,11 +619,11 @@ HTTPServer.prototype.filterBlock = function filterBlock(socket, block) {
  */
 
 HTTPServer.prototype.filterTX = function filterTX(socket, tx) {
-  let found = false;
-
   if (!socket.filter)
     return false;
 
+  let found = false;
+
   for (let i = 0; i < tx.outputs.length; i++) {
     const output = tx.outputs[i];
     const hash = output.getHash();
@@ -697,7 +701,7 @@ function HTTPOptions(options) {
   this.logger = null;
   this.node = null;
   this.apiKey = base58.encode(random.randomBytes(20));
-  this.apiHash = hash256(this.apiKey);
+  this.apiHash = digest.hash256(Buffer.from(this.apiKey, 'utf8'));
   this.noAuth = false;
 
   this.prefix = null;
@@ -736,10 +740,10 @@ HTTPOptions.prototype.fromOptions = function fromOptions(options) {
   if (options.apiKey != null) {
     assert(typeof options.apiKey === 'string',
       'API key must be a string.');
-    assert(options.apiKey.length <= 200,
-      'API key must be under 200 bytes.');
+    assert(options.apiKey.length <= 255,
+      'API key must be under 256 bytes.');
     this.apiKey = options.apiKey;
-    this.apiHash = hash256(this.apiKey);
+    this.apiHash = digest.hash256(Buffer.from(this.apiKey, 'utf8'));
   }
 
   if (options.noAuth != null) {
@@ -804,16 +808,6 @@ HTTPOptions.fromOptions = function fromOptions(options) {
  * Helpers
  */
 
-function hash256(data) {
-  if (typeof data !== 'string')
-    return Buffer.alloc(0);
-
-  if (data.length > 200)
-    return Buffer.alloc(0);
-
-  return digest.hash256(Buffer.from(data, 'utf8'));
-}
-
 function enforce(value, msg) {
   if (!value) {
     const err = new Error(msg);
diff --git a/lib/mempool/fees.js b/lib/mempool/fees.js
index c5226189..1598c34e 100644
--- a/lib/mempool/fees.js
+++ b/lib/mempool/fees.js
@@ -447,14 +447,16 @@ PolicyEstimator.VERSION = 0;
 PolicyEstimator.prototype.init = function init() {
   const minFee = this.minTrackedFee;
   const minPri = this.minTrackedPri;
+
   const fee = [];
-  const priority = [];
 
   for (let b = minFee; b <= MAX_FEERATE; b *= FEE_SPACING)
     fee.push(b);
 
   fee.push(INF_FEERATE);
 
+  const priority = [];
+
   for (let b = minPri; b <= MAX_PRIORITY; b *= PRI_SPACING)
     priority.push(b);
 
@@ -694,7 +696,7 @@ PolicyEstimator.prototype.estimateFee = function estimateFee(target, smart) {
     'Too many confirmations for estimate.');
 
   if (!smart) {
-    rate = this.feeStats.estimateMedian(
+    const rate = this.feeStats.estimateMedian(
       target, SUFFICIENT_FEETXS, MIN_SUCCESS_PCT,
       true, this.bestHeight);
 
diff --git a/lib/mempool/layout.js b/lib/mempool/layout.js
index 916dae74..3d009a56 100644
--- a/lib/mempool/layout.js
+++ b/lib/mempool/layout.js
@@ -41,7 +41,7 @@ function write(data, str, off) {
   if (Buffer.isBuffer(str))
     return str.copy(data, off);
   assert(typeof str === 'string');
-  data.write(str, off, 'hex');
+  return data.write(str, off, 'hex');
 }
 
 /*
diff --git a/lib/mempool/mempool.js b/lib/mempool/mempool.js
index 45f42ad8..7f82faa1 100644
--- a/lib/mempool/mempool.js
+++ b/lib/mempool/mempool.js
@@ -105,8 +105,6 @@ util.inherits(Mempool, AsyncObject);
  */
 
 Mempool.prototype._open = async function open() {
-  const size = (this.options.maxSize / 1024).toFixed(2);
-
   await this.chain.open();
   await this.cache.open();
 
@@ -143,6 +141,8 @@ Mempool.prototype._open = async function open() {
 
   this.tip = this.chain.tip.hash;
 
+  const size = (this.options.maxSize / 1024).toFixed(2);
+
   this.logger.info('Mempool loaded (maxsize=%dkb).', size);
 };
 
@@ -361,12 +361,13 @@ Mempool.prototype._reset = async function reset() {
 
 Mempool.prototype.limitSize = function limitSize(added) {
   const maxSize = this.options.maxSize;
-  const threshold = maxSize - (maxSize / 10);
-  const expiryTime = this.options.expiryTime;
 
   if (this.size <= maxSize)
     return false;
 
+  const threshold = maxSize - (maxSize / 10);
+  const expiryTime = this.options.expiryTime;
+
   const now = util.now();
   let start = util.hrtime();
   const queue = new Heap(cmpRate);
@@ -431,8 +432,10 @@ Mempool.prototype.limitSize = function limitSize(added) {
 
 Mempool.prototype.getTX = function getTX(hash) {
   const entry = this.map.get(hash);
+
   if (!entry)
-    return;
+    return null;
+
   return entry.tx;
 };
 
@@ -457,13 +460,13 @@ Mempool.prototype.getCoin = function getCoin(hash, index) {
   const entry = this.map.get(hash);
 
   if (!entry)
-    return;
+    return null;
 
   if (this.isSpent(hash, index))
-    return;
+    return null;
 
   if (index >= entry.tx.outputs.length)
-    return;
+    return null;
 
   return Coin.fromTX(entry.tx, index, -1);
 };
@@ -507,7 +510,7 @@ Mempool.prototype.getSpentTX = function getSpentTX(hash, index) {
   const entry = this.spents.get(key);
 
   if (!entry)
-    return;
+    return null;
 
   return entry.tx;
 };
@@ -519,11 +522,11 @@ Mempool.prototype.getSpentTX = function getSpentTX(hash, index) {
  */
 
 Mempool.prototype.getCoinsByAddress = function getCoinsByAddress(addrs) {
-  const out = [];
-
   if (!Array.isArray(addrs))
     addrs = [addrs];
 
+  const out = [];
+
   for (const addr of addrs) {
     const hash = Address.getHash(addr, 'hex');
     const coins = this.coinIndex.get(hash);
@@ -542,11 +545,11 @@ Mempool.prototype.getCoinsByAddress = function getCoinsByAddress(addrs) {
  */
 
 Mempool.prototype.getTXByAddress = function getTXByAddress(addrs) {
-  const out = [];
-
   if (!Array.isArray(addrs))
     addrs = [addrs];
 
+  const out = [];
+
   for (const addr of addrs) {
     const hash = Address.getHash(addr, 'hex');
     const txs = this.txIndex.get(hash);
@@ -565,11 +568,11 @@ Mempool.prototype.getTXByAddress = function getTXByAddress(addrs) {
  */
 
 Mempool.prototype.getMetaByAddress = function getMetaByAddress(addrs) {
-  const out = [];
-
   if (!Array.isArray(addrs))
     addrs = [addrs];
 
+  const out = [];
+
   for (const addr of addrs) {
     const hash = Address.getHash(addr, 'hex');
     const txs = this.txIndex.getMeta(hash);
@@ -591,7 +594,7 @@ Mempool.prototype.getMeta = function getMeta(hash) {
   const entry = this.getEntry(hash);
 
   if (!entry)
-    return;
+    return null;
 
   const meta = TXMeta.fromTX(entry.tx);
   meta.mtime = entry.time;
@@ -685,11 +688,10 @@ Mempool.prototype.addTX = async function addTX(tx, id) {
  */
 
 Mempool.prototype._addTX = async function _addTX(tx, id) {
-  let missing;
-
   if (id == null)
     id = -1;
 
+  let missing;
   try {
     missing = await this.insertTX(tx, id);
   } catch (err) {
@@ -859,7 +861,6 @@ Mempool.prototype.insertTX = async function insertTX(tx, id) {
 Mempool.prototype.verify = async function verify(entry, view) {
   const height = this.chain.height + 1;
   const lockFlags = common.lockFlags.STANDARD_LOCKTIME_FLAGS;
-  let flags = Script.flags.STANDARD_VERIFY_FLAGS;
   const tx = entry.tx;
 
   // Verify sequence locks.
@@ -949,6 +950,7 @@ Mempool.prototype.verify = async function verify(entry, view) {
     throw new VerifyError(tx, 'invalid', reason, score);
 
   // Script verification.
+  let flags = Script.flags.STANDARD_VERIFY_FLAGS;
   try {
     await this.verifyInputs(tx, view, flags);
   } catch (err) {
@@ -1414,8 +1416,6 @@ Mempool.prototype.hasOrphan = function hasOrphan(hash) {
  */
 
 Mempool.prototype.storeOrphan = function storeOrphan(tx, missing, id) {
-  const hash = tx.hash('hex');
-
   if (tx.getWeight() > policy.MAX_TX_WEIGHT) {
     this.logger.debug('Ignoring large orphan: %s', tx.txid());
     if (!tx.hasWitness())
@@ -1436,6 +1436,8 @@ Mempool.prototype.storeOrphan = function storeOrphan(tx, missing, id) {
 
   this.limitOrphans();
 
+  const hash = tx.hash('hex');
+
   for (const prev of missing) {
     if (!this.waiting.has(prev))
       this.waiting.set(prev, new Set());
@@ -1510,13 +1512,14 @@ Mempool.prototype.handleOrphans = async function handleOrphans(parent) {
 Mempool.prototype.resolveOrphans = function resolveOrphans(parent) {
   const hash = parent.hash('hex');
   const set = this.waiting.get(hash);
-  const resolved = [];
 
   if (!set)
-    return resolved;
+    return [];
 
   assert(set.size > 0);
 
+  const resolved = [];
+
   for (const orphanHash of set.keys()) {
     const orphan = this.getOrphan(orphanHash);
 
@@ -1541,11 +1544,11 @@ Mempool.prototype.resolveOrphans = function resolveOrphans(parent) {
 
 Mempool.prototype.removeOrphan = function removeOrphan(hash) {
   const orphan = this.getOrphan(hash);
-  let tx;
 
   if (!orphan)
     return false;
 
+  let tx;
   try {
     tx = orphan.toTX();
   } catch (e) {
@@ -1553,7 +1556,7 @@ Mempool.prototype.removeOrphan = function removeOrphan(hash) {
     this.logger.warning('%s %s',
       'Warning: possible memory corruption.',
       'Orphan failed deserialization.');
-    return;
+    return false;
   }
 
   for (const prev of tx.getPrevout()) {
@@ -1587,8 +1590,8 @@ Mempool.prototype.limitOrphans = function limitOrphans() {
     return false;
 
   let index = random.randomRange(0, this.orphans.size);
-  let hash = null;
 
+  let hash;
   for (hash of this.orphans.keys()) {
     if (index === 0)
       break;
@@ -1690,7 +1693,7 @@ Mempool.prototype.findMissing = function findMissing(tx, view) {
   }
 
   if (missing.length === 0)
-    return;
+    return null;
 
   return missing;
 };
@@ -2115,10 +2118,11 @@ TXIndex.prototype.reset = function reset() {
 
 TXIndex.prototype.get = function get(addr) {
   const items = this.index.get(addr);
-  const out = [];
 
   if (!items)
-    return out;
+    return [];
+
+  const out = [];
 
   for (const entry of items.values())
     out.push(entry.tx);
@@ -2128,10 +2132,11 @@ TXIndex.prototype.get = function get(addr) {
 
 TXIndex.prototype.getMeta = function getMeta(addr) {
   const items = this.index.get(addr);
-  const out = [];
 
   if (!items)
-    return out;
+    return [];
+
+  const out = [];
 
   for (const entry of items.values()) {
     const meta = TXMeta.fromTX(entry.tx);
@@ -2207,10 +2212,11 @@ CoinIndex.prototype.reset = function reset() {
 
 CoinIndex.prototype.get = function get(addr) {
   const items = this.index.get(addr);
-  const out = [];
 
   if (!items)
-    return out;
+    return [];
+
+  const out = [];
 
   for (const coin of items.values())
     out.push(coin.toCoin());
@@ -2332,18 +2338,18 @@ MempoolCache.prototype.getTip = async function getTip() {
   const hash = await this.db.get(layout.R);
 
   if (!hash)
-    return;
+    return null;
 
   return hash.toString('hex');
 };
 
 MempoolCache.prototype.getFees = async function getFees() {
   const data = await this.db.get(layout.F);
-  let fees;
 
   if (!data)
-    return;
+    return null;
 
+  let fees;
   try {
     fees = Fees.fromRaw(data);
   } catch (e) {
diff --git a/lib/mempool/mempoolentry.js b/lib/mempool/mempoolentry.js
index 1416c009..2ca6f637 100644
--- a/lib/mempool/mempoolentry.js
+++ b/lib/mempool/mempoolentry.js
@@ -97,8 +97,8 @@ MempoolEntry.prototype.fromTX = function fromTX(tx, view, height) {
   const size = tx.getSigopsSize(sigops);
   const priority = tx.getPriority(view, height, size);
   const fee = tx.getFee(view);
-  let dependencies = false;
 
+  let dependencies = false;
   for (const {prevout} of tx.inputs) {
     if (view.getHeight(prevout) === -1) {
       dependencies = true;
diff --git a/lib/mining/cpuminer.js b/lib/mining/cpuminer.js
index 9abc0fa0..15cd3a7d 100644
--- a/lib/mining/cpuminer.js
+++ b/lib/mining/cpuminer.js
@@ -128,8 +128,7 @@ CPUMiner.prototype._start = async function start() {
     if (this.stopping)
       break;
 
-    let block = null;
-
+    let block;
     try {
       block = await this.mineAsync(this.job);
     } catch (e) {
@@ -145,8 +144,7 @@ CPUMiner.prototype._start = async function start() {
     if (!block)
       continue;
 
-    let entry = null;
-
+    let entry;
     try {
       entry = await this.chain.add(block);
     } catch (e) {
@@ -295,6 +293,7 @@ CPUMiner.prototype.findNonce = function findNonce(job) {
   const data = job.getHeader();
   const target = job.attempt.target;
   const interval = CPUMiner.INTERVAL;
+
   let min = 0;
   let max = interval;
   let nonce;
@@ -322,16 +321,17 @@ CPUMiner.prototype.findNonce = function findNonce(job) {
  */
 
 CPUMiner.prototype.findNonceAsync = async function findNonceAsync(job) {
+  if (!this.workers)
+    return this.findNonce(job);
+
   const data = job.getHeader();
   const target = job.attempt.target;
   const interval = CPUMiner.INTERVAL;
+
   let min = 0;
   let max = interval;
   let nonce;
 
-  if (!this.workers)
-    return this.findNonce(job);
-
   while (max <= 0xffffffff) {
     nonce = await this.workers.mine(data, target, min, max);
 
@@ -357,10 +357,9 @@ CPUMiner.prototype.findNonceAsync = async function findNonceAsync(job) {
  */
 
 CPUMiner.prototype.mine = function mine(job) {
-  let nonce;
-
   job.start = util.now();
 
+  let nonce;
   for (;;) {
     nonce = this.findNonce(job);
 
@@ -394,7 +393,7 @@ CPUMiner.prototype.mineAsync = async function mineAsync(job) {
       break;
 
     if (job.destroyed)
-      return;
+      return null;
 
     job.updateNonce();
 
diff --git a/lib/mining/miner.js b/lib/mining/miner.js
index 55d2b4b4..496f4f38 100644
--- a/lib/mining/miner.js
+++ b/lib/mining/miner.js
@@ -259,7 +259,7 @@ Miner.prototype.assemble = function assemble(attempt) {
 
   if (!this.mempool) {
     attempt.refresh();
-    return [];
+    return;
   }
 
   assert(this.mempool.tip === this.chain.tip.hash,
diff --git a/lib/net/bip150.js b/lib/net/bip150.js
index 5cab81d0..469b2cd5 100644
--- a/lib/net/bip150.js
+++ b/lib/net/bip150.js
@@ -178,7 +178,7 @@ BIP150.prototype.reply = function reply(data) {
   if (this.isAuthed()) {
     this.auth = true;
     this.emit('auth');
-    return;
+    return null;
   }
 
   assert(this.outbound, 'No challenge received before reply on inbound.');
@@ -321,6 +321,8 @@ BIP150.prototype.findAuthorized = function findAuthorized(hash) {
     if (ccmp(msg, hash))
       return key;
   }
+
+  return null;
 };
 
 /**
@@ -630,12 +632,11 @@ AuthDB.prototype.lookup = async function lookup() {
  */
 
 AuthDB.prototype.populate = async function populate(addr, key) {
-  let hosts;
-
   assert(addr.type === IP.types.DNS, 'Resolved host passed.');
 
   this.logger.info('Resolving authorized hosts from: %s.', addr.host);
 
+  let hosts;
   try {
     hosts = await this.resolve(addr.host);
   } catch (e) {
@@ -665,8 +666,8 @@ AuthDB.prototype.readKnown = async function readKnown() {
     return;
 
   const file = path.join(this.prefix, 'known-peers');
-  let text;
 
+  let text;
   try {
     text = await fs.readFile(file, 'utf8');
   } catch (e) {
@@ -702,8 +703,8 @@ AuthDB.prototype.parseKnown = function parseKnown(text) {
       continue;
 
     const hostname = parts[0].trim().split(',');
-    let host, ip;
 
+    let host, ip;
     if (hostname.length >= 2) {
       host = hostname[0];
       ip = hostname[1];
@@ -742,8 +743,8 @@ AuthDB.prototype.readAuth = async function readAuth() {
     return;
 
   const file = path.join(this.prefix, 'authorized-peers');
-  let text;
 
+  let text;
   try {
     text = await fs.readFile(file, 'utf8');
   } catch (e) {
diff --git a/lib/net/bip152.js b/lib/net/bip152.js
index 090fb613..f2e44d72 100644
--- a/lib/net/bip152.js
+++ b/lib/net/bip152.js
@@ -300,7 +300,7 @@ CompactBlock.prototype.fillMempool = function fillMempool(witness, mempool) {
   if (this.count === this.totalTX)
     return true;
 
-  const have = new Set();
+  const set = new Set();
 
   for (const {tx} of mempool.map.values()) {
     let hash = tx.hash();
@@ -314,7 +314,7 @@ CompactBlock.prototype.fillMempool = function fillMempool(witness, mempool) {
     if (index == null)
       continue;
 
-    if (have.has(index)) {
+    if (set.has(index)) {
       // Siphash collision, just request it.
       this.available[index] = null;
       this.count--;
@@ -322,7 +322,7 @@ CompactBlock.prototype.fillMempool = function fillMempool(witness, mempool) {
     }
 
     this.available[index] = tx;
-    have.add(index);
+    set.add(index);
     this.count++;
 
     // We actually may have a siphash collision
@@ -619,7 +619,6 @@ TXRequest.prototype.fromReader = function fromReader(br) {
   this.hash = br.readHash('hex');
 
   const count = br.readVarint();
-  let offset = 0;
 
   for (let i = 0; i < count; i++) {
     const index = br.readVarint();
@@ -627,6 +626,8 @@ TXRequest.prototype.fromReader = function fromReader(br) {
     this.indexes.push(index);
   }
 
+  let offset = 0;
+
   for (let i = 0; i < count; i++) {
     let index = this.indexes[i];
     index += offset;
diff --git a/lib/net/external.js b/lib/net/external.js
index 37510dbc..b455e5cb 100644
--- a/lib/net/external.js
+++ b/lib/net/external.js
@@ -22,34 +22,24 @@ const external = exports;
  */
 
 external.getIPv4 = async function getIPv4() {
-  let res = null;
-
   try {
-    res = await request({
+    const res = await request({
       method: 'GET',
       uri: 'http://ipv4.icanhazip.com',
       expect: 'txt',
       timeout: 2000
     });
-  } catch (e) {
-    return await external.getIPv42();
-  }
 
-  let ip = null;
-
-  try {
     const str = res.body.trim();
     const raw = IP.toBuffer(str);
 
     if (!IP.isIPv4(raw))
       throw new Error('Could not find IPv4.');
 
-    ip = IP.toString(raw);
+    return IP.toString(raw);
   } catch (e) {
     return await external.getIPv42();
   }
-
-  return ip;
 };
 
 /**
diff --git a/lib/net/hostlist.js b/lib/net/hostlist.js
index a7561b50..15fb9dd2 100644
--- a/lib/net/hostlist.js
+++ b/lib/net/hostlist.js
@@ -403,9 +403,7 @@ HostList.prototype.isBanned = function isBanned(host) {
  */
 
 HostList.prototype.getHost = function getHost() {
-  const now = this.network.now();
   let buckets = null;
-  let factor = 1;
 
   if (this.totalFresh > 0)
     buckets = this.fresh;
@@ -416,7 +414,10 @@ HostList.prototype.getHost = function getHost() {
   }
 
   if (!buckets)
-    return;
+    return null;
+
+  const now = this.network.now();
+  let factor = 1;
 
   for (;;) {
     let index = util.random(0, buckets.length);
@@ -653,7 +654,7 @@ HostList.prototype.remove = function remove(hostname) {
   const entry = this.map.get(hostname);
 
   if (!entry)
-    return;
+    return null;
 
   if (entry.used) {
     let head = entry;
@@ -832,7 +833,7 @@ HostList.prototype.addSeed = function addSeed(host) {
   if (ip.type === IP.types.DNS) {
     // Defer for resolution.
     this.dnsSeeds.push(ip);
-    return;
+    return null;
   }
 
   const addr = NetAddress.fromHost(ip.host, ip.port, this.network);
@@ -854,7 +855,7 @@ HostList.prototype.addNode = function addNode(host) {
   if (ip.type === IP.types.DNS) {
     // Defer for resolution.
     this.dnsNodes.push(ip);
-    return;
+    return null;
   }
 
   const addr = NetAddress.fromHost(ip.host, ip.port, this.network);
diff --git a/lib/net/parser.js b/lib/net/parser.js
index a53c1915..a1801f31 100644
--- a/lib/net/parser.js
+++ b/lib/net/parser.js
@@ -102,8 +102,7 @@ Parser.prototype.parse = function parse(data) {
     return;
   }
 
-  let payload = null;
-
+  let payload;
   try {
     payload = this.parsePayload(this.header.cmd, data);
   } catch (e) {
diff --git a/lib/net/peer.js b/lib/net/peer.js
index 5e70dba7..43a9390c 100644
--- a/lib/net/peer.js
+++ b/lib/net/peer.js
@@ -511,10 +511,12 @@ Peer.prototype._open = async function open() {
 Peer.prototype.initConnect = function initConnect() {
   if (this.connected) {
     assert(!this.outbound);
-    return;
+    return Promise.resolve();
   }
 
   return new Promise((resolve, reject) => {
+    /* eslint no-use-before-define: "off" */
+
     const cleanup = () => {
       if (this.connectTimeout != null) {
         clearTimeout(this.connectTimeout);
@@ -703,8 +705,6 @@ Peer.prototype.finalize = async function finalize() {
  */
 
 Peer.prototype.announceBlock = function announceBlock(blocks) {
-  const inv = [];
-
   if (!this.handshake)
     return;
 
@@ -714,6 +714,8 @@ Peer.prototype.announceBlock = function announceBlock(blocks) {
   if (!Array.isArray(blocks))
     blocks = [blocks];
 
+  const inv = [];
+
   for (const block of blocks) {
     assert(block instanceof Block);
 
@@ -753,8 +755,6 @@ Peer.prototype.announceBlock = function announceBlock(blocks) {
  */
 
 Peer.prototype.announceTX = function announceTX(txs) {
-  const inv = [];
-
   if (!this.handshake)
     return;
 
@@ -769,6 +769,8 @@ Peer.prototype.announceTX = function announceTX(txs) {
   if (!Array.isArray(txs))
     txs = [txs];
 
+  const inv = [];
+
   for (const tx of txs) {
     assert(tx instanceof TX);
 
@@ -830,20 +832,21 @@ Peer.prototype.queueInv = function queueInv(items) {
  */
 
 Peer.prototype.flushInv = function flushInv() {
-  const queue = this.invQueue.slice();
-  const items = [];
-
   if (this.destroyed)
     return;
 
+  const queue = this.invQueue;
+
   if (queue.length === 0)
     return;
 
-  this.invQueue.length = 0;
+  this.invQueue = [];
 
   this.logger.spam('Serving %d inv items to %s.',
     queue.length, this.hostname());
 
+  const items = [];
+
   for (const item of queue) {
     if (!this.invFilter.added(item.hash, 'hex'))
       continue;
@@ -1336,7 +1339,7 @@ Peer.prototype.maybeTimeout = function maybeTimeout() {
 
 Peer.prototype.request = function request(type, timeout) {
   if (this.destroyed)
-    return;
+    return null;
 
   let entry = this.responseMap.get(type);
 
@@ -1361,7 +1364,7 @@ Peer.prototype.response = function response(type, payload) {
   const entry = this.responseMap.get(type);
 
   if (!entry)
-    return;
+    return null;
 
   this.responseMap.delete(type);
 
@@ -1989,12 +1992,12 @@ Peer.prototype.handleAuthPropose = async function handleAuthPropose(packet) {
 
 Peer.prototype.sendGetHeaders = function sendGetHeaders(locator, stop) {
   const packet = new packets.GetHeadersPacket(locator, stop);
-  let hash = null;
-  let end = null;
 
+  let hash = null;
   if (packet.locator.length > 0)
     hash = util.revHex(packet.locator[0]);
 
+  let end = null;
   if (stop)
     end = util.revHex(stop);
 
@@ -2017,12 +2020,12 @@ Peer.prototype.sendGetHeaders = function sendGetHeaders(locator, stop) {
 
 Peer.prototype.sendGetBlocks = function getBlocks(locator, stop) {
   const packet = new packets.GetBlocksPacket(locator, stop);
-  let hash = null;
-  let end = null;
 
+  let hash = null;
   if (packet.locator.length > 0)
     hash = util.revHex(packet.locator[0]);
 
+  let end = null;
   if (stop)
     end = util.revHex(stop);
 
diff --git a/lib/net/pool.js b/lib/net/pool.js
index 43160360..58033f2b 100644
--- a/lib/net/pool.js
+++ b/lib/net/pool.js
@@ -463,15 +463,14 @@ Pool.prototype.discoverGateway = async function discoverGateway() {
 
   // Pointless if we're not listening.
   if (!this.options.listen)
-    return;
+    return false;
 
   // UPNP is always optional, since
   // it's likely to not work anyway.
   if (!this.options.upnp)
-    return;
-
-  let wan = null;
+    return false;
 
+  let wan;
   try {
     this.logger.debug('Discovering internet gateway (upnp).');
     wan = await UPNP.discover();
@@ -481,8 +480,7 @@ Pool.prototype.discoverGateway = async function discoverGateway() {
     return false;
   }
 
-  let host = null;
-
+  let host;
   try {
     host = await wan.getExternalIP();
   } catch (e) {
@@ -523,7 +521,6 @@ Pool.prototype.discoverSeeds = async function discoverSeeds(checkPeers) {
   const size = this.hosts.size();
 
   let total = 0;
-
   for (let peer = this.peers.head(); peer; peer = peer.next) {
     if (!peer.outbound)
       continue;
@@ -569,8 +566,7 @@ Pool.prototype.discoverExternal = async function discoverExternal() {
   if (this.hosts.local.size > 0)
     return;
 
-  let host4 = null;
-
+  let host4;
   try {
     host4 = await external.getIPv4();
   } catch (e) {
@@ -581,8 +577,7 @@ Pool.prototype.discoverExternal = async function discoverExternal() {
   if (host4 && this.hosts.addLocal(host4, port, scores.HTTP))
     this.logger.info('External IPv4 found (http): %s.', host4);
 
-  let host6 = null;
-
+  let host6;
   try {
     host6 = await external.getIPv6();
   } catch (e) {
@@ -767,8 +762,7 @@ Pool.prototype.resync = async function resync(force) {
   if (!this.syncing)
     return;
 
-  let locator = null;
-
+  let locator;
   try {
     locator = await this.chain.getLocator();
   } catch (e) {
@@ -834,8 +828,7 @@ Pool.prototype.sendSync = async function sendSync(peer) {
   peer.syncing = true;
   peer.blockTime = util.ms();
 
-  let locator = null;
-
+  let locator;
   try {
     locator = await this.chain.getLocator();
   } catch (e) {
@@ -1000,13 +993,13 @@ Pool.prototype.getBroadcasted = function getBroadcasted(peer, item) {
   const entry = this.invMap.get(item.hash);
 
   if (!entry)
-    return;
+    return null;
 
   if (type !== entry.type) {
     this.logger.debug(
       'Peer requested item with the wrong type (%s).',
       peer.hostname());
-    return;
+    return null;
   }
 
   this.logger.debug(
@@ -1037,19 +1030,19 @@ Pool.prototype.getItem = async function getItem(peer, item) {
     return entry;
 
   if (this.options.selfish)
-    return;
+    return null;
 
   if (item.isTX()) {
     if (!this.mempool)
-      return;
+      return null;
     return this.mempool.getTX(item.hash);
   }
 
   if (this.chain.options.spv)
-    return;
+    return null;
 
   if (this.chain.options.prune)
-    return;
+    return null;
 
   return await this.chain.db.getBlock(item.hash);
 };
@@ -1683,8 +1676,6 @@ Pool.prototype._handleInv = async function handleInv(peer, packet) {
  */
 
 Pool.prototype.handleBlockInv = async function handleBlockInv(peer, hashes) {
-  const items = [];
-
   assert(hashes.length > 0);
 
   if (!this.syncing)
@@ -1712,7 +1703,8 @@ Pool.prototype.handleBlockInv = async function handleBlockInv(peer, hashes) {
     hashes.length,
     peer.hostname());
 
-  let exists = null;
+  const items = [];
+  let exists;
 
   for (let i = 0; i < hashes.length; i++) {
     const hash = hashes[i];
@@ -1968,8 +1960,6 @@ Pool.prototype.handleNotFound = async function handleNotFound(peer, packet) {
  */
 
 Pool.prototype.handleGetBlocks = async function handleGetBlocks(peer, packet) {
-  const blocks = [];
-
   if (!this.chain.synced)
     return;
 
@@ -1987,6 +1977,8 @@ Pool.prototype.handleGetBlocks = async function handleGetBlocks(peer, packet) {
   if (hash)
     hash = await this.chain.db.getNextHash(hash);
 
+  const blocks = [];
+
   while (hash) {
     blocks.push(new InvItem(invTypes.BLOCK, hash));
 
@@ -2025,8 +2017,7 @@ Pool.prototype.handleGetHeaders = async function handleGetHeaders(peer, packet)
   if (this.chain.options.prune)
     return;
 
-  let hash = null;
-
+  let hash;
   if (packet.locator.length > 0) {
     hash = await this.chain.findLocator(packet.locator);
     if (hash)
@@ -2035,8 +2026,7 @@ Pool.prototype.handleGetHeaders = async function handleGetHeaders(peer, packet)
     hash = packet.stop;
   }
 
-  let entry = null;
-
+  let entry;
   if (hash)
     entry = await this.chain.db.getEntry(hash);
 
@@ -2270,8 +2260,7 @@ Pool.prototype._addBlock = async function addBlock(peer, block, flags) {
 
   peer.blockTime = util.ms();
 
-  let entry = null;
-
+  let entry;
   try {
     entry = await this.chain.add(block, flags, peer.id);
   } catch (err) {
@@ -2535,8 +2524,7 @@ Pool.prototype._handleTX = async function handleTX(peer, packet) {
     return;
   }
 
-  let missing = null;
-
+  let missing;
   try {
     missing = await this.mempool.addTX(tx, peer.id);
   } catch (err) {
@@ -2594,8 +2582,6 @@ Pool.prototype.handleReject = async function handleReject(peer, packet) {
  */
 
 Pool.prototype.handleMempool = async function handleMempool(peer, packet) {
-  const items = [];
-
   if (!this.mempool)
     return;
 
@@ -2613,6 +2599,8 @@ Pool.prototype.handleMempool = async function handleMempool(peer, packet) {
     return;
   }
 
+  const items = [];
+
   for (const hash of this.mempool.map.keys())
     items.push(new InvItem(invTypes.TX, hash));
 
@@ -2775,7 +2763,6 @@ Pool.prototype.handleCmpctBlock = async function handleCmpctBlock(peer, packet)
   const block = packet.block;
   const hash = block.hash('hex');
   const witness = peer.compactWitness;
-  const flags = chainCommon.flags.VERIFY_BODY;
 
   if (!this.syncing)
     return;
@@ -2862,6 +2849,7 @@ Pool.prototype.handleCmpctBlock = async function handleCmpctBlock(peer, packet)
     this.logger.debug(
       'Received full compact block %s (%s).',
       block.rhash(), peer.hostname());
+    const flags = chainCommon.flags.VERIFY_BODY;
     await this.addBlock(peer, block.toBlock(), flags);
     return;
   }
@@ -3080,9 +3068,6 @@ Pool.prototype.addInbound = function addInbound(socket) {
  */
 
 Pool.prototype.getHost = function getHost() {
-  const services = this.options.getRequiredServices();
-  const now = this.network.now();
-
   for (const addr of this.hosts.nodes) {
     if (this.peers.has(addr.hostname))
       continue;
@@ -3090,6 +3075,9 @@ Pool.prototype.getHost = function getHost() {
     return addr;
   }
 
+  const services = this.options.getRequiredServices();
+  const now = this.network.now();
+
   for (let i = 0; i < 100; i++) {
     const entry = this.hosts.getHost();
 
@@ -3121,6 +3109,8 @@ Pool.prototype.getHost = function getHost() {
 
     return entry.addr;
   }
+
+  return null;
 };
 
 /**
@@ -4389,20 +4379,20 @@ function NonceList() {
 }
 
 NonceList.prototype.alloc = function alloc(hostname) {
-  let nonce, key;
-
   for (;;) {
-    nonce = util.nonce();
-    key = nonce.toString('hex');
-    if (!this.map.has(key)) {
-      this.map.set(key, hostname);
-      assert(!this.hosts.has(hostname));
-      this.hosts.set(hostname, key);
-      break;
-    }
-  }
+    const nonce = util.nonce();
+    const key = nonce.toString('hex');
 
-  return nonce;
+    if (this.map.has(key))
+      continue;
+
+    this.map.set(key, hostname);
+
+    assert(!this.hosts.has(hostname));
+    this.hosts.set(hostname, key);
+
+    return nonce;
+  }
 };
 
 NonceList.prototype.has = function has(nonce) {
diff --git a/lib/net/proxysocket.js b/lib/net/proxysocket.js
index c2464721..f6949acd 100644
--- a/lib/net/proxysocket.js
+++ b/lib/net/proxysocket.js
@@ -101,8 +101,6 @@ ProxySocket.prototype._init = function _init() {
 };
 
 ProxySocket.prototype.connect = function connect(port, host) {
-  let nonce = 0;
-
   this.remoteAddress = host;
   this.remotePort = port;
 
@@ -116,14 +114,17 @@ ProxySocket.prototype.connect = function connect(port, host) {
     return;
   }
 
-  if (this.info.pow) {
-    let pow = new BufferWriter();
+  let nonce = 0;
 
-    pow.writeU32(nonce);
-    pow.writeBytes(this.snonce);
-    pow.writeU32(port);
-    pow.writeString(host, 'ascii');
-    pow = pow.render();
+  if (this.info.pow) {
+    const bw = new BufferWriter();
+
+    bw.writeU32(nonce);
+    bw.writeBytes(this.snonce);
+    bw.writeU32(port);
+    bw.writeString(host, 'ascii');
+
+    const pow = bw.render();
 
     util.log(
       'Solving proof of work to create socket (%d, %s) -- please wait.',
diff --git a/lib/net/socks.js b/lib/net/socks.js
index 92d121c1..f6380029 100644
--- a/lib/net/socks.js
+++ b/lib/net/socks.js
@@ -428,8 +428,7 @@ SOCKS.prototype.handleProxy = function handleProxy(data) {
     return;
   }
 
-  let addr = null;
-
+  let addr;
   try {
     addr = parseAddr(data, 3);
   } catch (e) {
@@ -487,8 +486,7 @@ SOCKS.prototype.handleResolve = function handleResolve(data) {
     return;
   }
 
-  let addr = null;
-
+  let addr;
   try {
     addr = parseAddr(data, 3);
   } catch (e) {
@@ -569,8 +567,7 @@ Proxy.prototype.connect = async function connect(port, host) {
     destPort: port
   };
 
-  let socket = null;
-
+  let socket;
   try {
     socket = await SOCKS.proxy(options);
   } catch (e) {
@@ -708,9 +705,7 @@ function parseAddr(data, offset) {
   br.seek(offset);
 
   const type = br.readU8();
-
-  let host = null;
-  let port = 0;
+  let host, port;
 
   switch (type) {
     case 0x01: {
diff --git a/lib/net/upnp.js b/lib/net/upnp.js
index ba30f4ab..806c2671 100644
--- a/lib/net/upnp.js
+++ b/lib/net/upnp.js
@@ -191,8 +191,7 @@ UPNP.prototype.handleMsg = async function handleMsg(msg) {
   if (!this.socket)
     return;
 
-  let headers = null;
-
+  let headers;
   try {
     headers = UPNP.parseHeader(msg);
   } catch (e) {
@@ -271,7 +270,7 @@ UPNP.parseHeader = function parseHeader(str) {
     const index = line.indexOf(':');
 
     if (index === -1) {
-      left = line.toLowerCase();
+      const left = line.toLowerCase();
       headers[left] = '';
       continue;
     }
@@ -615,6 +614,8 @@ XMLElement.prototype.find = function find(name) {
     if (child)
       return child;
   }
+
+  return null;
 };
 
 /*
@@ -649,6 +650,8 @@ function findService(services, name) {
     if (service.serviceType === name)
       return service;
   }
+
+  return null;
 }
 
 function extractServices(services, targets) {
@@ -657,13 +660,15 @@ function extractServices(services, targets) {
     if (service)
       return service;
   }
+
+  return null;
 }
 
 function findIP(el) {
   const child = el.find('NewExternalIPAddress');
 
   if (!child)
-    return;
+    return null;
 
   return IP.normalize(child.text);
 }
@@ -672,7 +677,7 @@ function findError(el) {
   const child = el.find('UPnPError');
 
   if (!child)
-    return;
+    return null;
 
   let code = -1;
   const ccode = child.find('errorCode');
diff --git a/lib/node/config.js b/lib/node/config.js
index 40dcd826..dbf8d9d0 100644
--- a/lib/node/config.js
+++ b/lib/node/config.js
@@ -702,8 +702,7 @@ Config.prototype.parseArg = function parseArg(argv) {
 
   assert(Array.isArray(argv));
 
-  let key = null;
-
+  let key;
   for (let i = 2; i < argv.length; i++) {
     let arg = argv[i];
     let value, alias, equals;
diff --git a/lib/node/fullnode.js b/lib/node/fullnode.js
index 852c5688..96de2d57 100644
--- a/lib/node/fullnode.js
+++ b/lib/node/fullnode.js
@@ -379,16 +379,16 @@ FullNode.prototype.getBlock = function getBlock(hash) {
  * @returns {Promise} - Returns {@link Coin}.
  */
 
-FullNode.prototype.getCoin = function getCoin(hash, index) {
+FullNode.prototype.getCoin = async function getCoin(hash, index) {
   const coin = this.mempool.getCoin(hash, index);
 
   if (coin)
-    return Promise.resolve(coin);
+    return coin;
 
   if (this.mempool.isSpent(hash, index))
-    return Promise.resolve();
+    return null;
 
-  return this.chain.db.getCoin(hash, index);
+  return await this.chain.db.getCoin(hash, index);
 };
 
 /**
@@ -483,8 +483,10 @@ FullNode.prototype.getTXByAddress = async function getTXByAddress(addrs) {
 
 FullNode.prototype.getTX = async function getTX(hash) {
   const mtx = await this.getMeta(hash);
+
   if (!mtx)
-    return;
+    return null;
+
   return mtx.tx;
 };
 
diff --git a/lib/node/logger.js b/lib/node/logger.js
index f9950e20..215b5a28 100644
--- a/lib/node/logger.js
+++ b/lib/node/logger.js
@@ -253,8 +253,6 @@ Logger.prototype._close = async function close() {
  */
 
 Logger.prototype.truncate = async function truncate() {
-  const maxSize = Logger.MAX_FILE_SIZE;
-
   if (!this.filename)
     return;
 
@@ -263,8 +261,7 @@ Logger.prototype.truncate = async function truncate() {
 
   assert(!this.stream);
 
-  let stat = null;
-
+  let stat;
   try {
     stat = await fs.stat(this.filename);
   } catch (e) {
@@ -273,6 +270,8 @@ Logger.prototype.truncate = async function truncate() {
     throw e;
   }
 
+  const maxSize = Logger.MAX_FILE_SIZE;
+
   if (stat.size <= maxSize + (maxSize / 10))
     return;
 
@@ -390,11 +389,11 @@ Logger.prototype.setLevel = function setLevel(name) {
  */
 
 Logger.prototype.error = function error(...args) {
-  const err = args[0];
-
   if (this.level < Logger.levels.ERROR)
     return;
 
+  const err = args[0];
+
   if (err instanceof Error)
     return this.logError(Logger.levels.ERROR, null, err);
 
@@ -408,11 +407,11 @@ Logger.prototype.error = function error(...args) {
  */
 
 Logger.prototype.warning = function warning(...args) {
-  const err = args[0];
-
   if (this.level < Logger.levels.WARNING)
     return;
 
+  const err = args[0];
+
   if (err instanceof Error)
     return this.logError(Logger.levels.WARNING, null, err);
 
@@ -426,11 +425,11 @@ Logger.prototype.warning = function warning(...args) {
  */
 
 Logger.prototype.info = function info(...args) {
-  const err = args[0];
-
   if (this.level < Logger.levels.INFO)
     return;
 
+  const err = args[0];
+
   if (err instanceof Error)
     return this.logError(Logger.levels.INFO, null, err);
 
@@ -444,11 +443,11 @@ Logger.prototype.info = function info(...args) {
  */
 
 Logger.prototype.debug = function debug(...args) {
-  const err = args[0];
-
   if (this.level < Logger.levels.DEBUG)
     return;
 
+  const err = args[0];
+
   if (err instanceof Error)
     return this.logError(Logger.levels.DEBUG, null, err);
 
@@ -462,11 +461,11 @@ Logger.prototype.debug = function debug(...args) {
  */
 
 Logger.prototype.spam = function spam(...args) {
-  const err = args[0];
-
   if (this.level < Logger.levels.SPAM)
     return;
 
+  const err = args[0];
+
   if (err instanceof Error)
     return this.logError(Logger.levels.SPAM, null, err);
 
@@ -518,7 +517,6 @@ Logger.prototype.context = function _context(module) {
 
 Logger.prototype.writeConsole = function writeConsole(level, module, args) {
   const name = Logger.levelsByVal[level];
-  let msg = '';
 
   assert(name, 'Invalid log level.');
 
@@ -526,7 +524,7 @@ Logger.prototype.writeConsole = function writeConsole(level, module, args) {
     return;
 
   if (!process.stdout) {
-    msg += `[${name}] `;
+    let msg = `[${name}] `;
 
     if (module)
       msg += `(${module}) `;
@@ -544,13 +542,15 @@ Logger.prototype.writeConsole = function writeConsole(level, module, args) {
       : console.log(msg);
   }
 
+  let msg;
+
   if (this.colors) {
     const color = Logger.styles[level];
     assert(color);
 
-    msg += `\x1b[${color}m[${name}]\x1b[m `;
+    msg = `\x1b[${color}m[${name}]\x1b[m `;
   } else {
-    msg += `[${name}] `;
+    msg = `[${name}] `;
   }
 
   if (module)
@@ -573,7 +573,6 @@ Logger.prototype.writeConsole = function writeConsole(level, module, args) {
 
 Logger.prototype.writeStream = function writeStream(level, module, args) {
   const name = Logger.prefixByVal[level];
-  let msg = '';
 
   assert(name, 'Invalid log level.');
 
@@ -583,7 +582,7 @@ Logger.prototype.writeStream = function writeStream(level, module, args) {
   if (this.closing)
     return;
 
-  msg += `[${name}:${util.date()}] `;
+  let msg = `[${name}:${util.date()}] `;
 
   if (module)
     msg += `(${module}) `;
@@ -703,11 +702,11 @@ LoggerContext.prototype.setLevel = function setLevel(name) {
  */
 
 LoggerContext.prototype.error = function error(...args) {
-  const err = args[0];
-
   if (this.logger.level < Logger.levels.ERROR)
     return;
 
+  const err = args[0];
+
   if (err instanceof Error)
     return this.logError(Logger.levels.ERROR, err);
 
@@ -721,11 +720,11 @@ LoggerContext.prototype.error = function error(...args) {
  */
 
 LoggerContext.prototype.warning = function warning(...args) {
-  const err = args[0];
-
   if (this.logger.level < Logger.levels.WARNING)
     return;
 
+  const err = args[0];
+
   if (err instanceof Error)
     return this.logError(Logger.levels.WARNING, err);
 
@@ -739,11 +738,11 @@ LoggerContext.prototype.warning = function warning(...args) {
  */
 
 LoggerContext.prototype.info = function info(...args) {
-  const err = args[0];
-
   if (this.logger.level < Logger.levels.INFO)
     return;
 
+  const err = args[0];
+
   if (err instanceof Error)
     return this.logError(Logger.levels.INFO, err);
 
@@ -757,11 +756,11 @@ LoggerContext.prototype.info = function info(...args) {
  */
 
 LoggerContext.prototype.debug = function debug(...args) {
-  const err = args[0];
-
   if (this.logger.level < Logger.levels.DEBUG)
     return;
 
+  const err = args[0];
+
   if (err instanceof Error)
     return this.logError(Logger.levels.DEBUG, err);
 
@@ -775,11 +774,11 @@ LoggerContext.prototype.debug = function debug(...args) {
  */
 
 LoggerContext.prototype.spam = function spam(...args) {
-  const err = args[0];
-
   if (this.logger.level < Logger.levels.SPAM)
     return;
 
+  const err = args[0];
+
   if (err instanceof Error)
     return this.logError(Logger.levels.SPAM, err);
 
@@ -839,12 +838,9 @@ Logger.global = new Logger();
 
 function openStream(filename) {
   return new Promise((resolve, reject) => {
-    const stream = fs.createWriteStream(filename, { flags: 'a' });
+    /* eslint no-use-before-define: "off" */
 
-    const cleanup = () => {
-      stream.removeListener('error', onError);
-      stream.removeListener('open', onOpen);
-    };
+    const stream = fs.createWriteStream(filename, { flags: 'a' });
 
     const onError = (err) => {
       try {
@@ -861,6 +857,11 @@ function openStream(filename) {
       resolve(stream);
     };
 
+    const cleanup = () => {
+      stream.removeListener('error', onError);
+      stream.removeListener('open', onOpen);
+    };
+
     stream.once('error', onError);
     stream.once('open', onOpen);
   });
@@ -868,10 +869,7 @@ function openStream(filename) {
 
 function closeStream(stream) {
   return new Promise((resolve, reject) => {
-    const cleanup = () => {
-      stream.removeListener('error', onError);
-      stream.removeListener('close', onClose);
-    };
+    /* eslint no-use-before-define: "off" */
 
     const onError = (err) => {
       cleanup();
@@ -883,6 +881,11 @@ function closeStream(stream) {
       resolve(stream);
     };
 
+    const cleanup = () => {
+      stream.removeListener('error', onError);
+      stream.removeListener('close', onClose);
+    };
+
     stream.removeAllListeners('error');
     stream.removeAllListeners('close');
     stream.once('error', onError);
diff --git a/lib/node/node.js b/lib/node/node.js
index fe03392a..d27615cb 100644
--- a/lib/node/node.js
+++ b/lib/node/node.js
@@ -352,7 +352,7 @@ Node.prototype.get = function get(name) {
       return this.http;
   }
 
-  return this.plugins[name];
+  return this.plugins[name] || null;
 };
 
 /**
diff --git a/lib/primitives/address.js b/lib/primitives/address.js
index d6487a11..483201c5 100644
--- a/lib/primitives/address.js
+++ b/lib/primitives/address.js
@@ -460,6 +460,8 @@ Address.prototype.fromScript = function fromScript(script) {
     this.version = -1;
     return this;
   }
+
+  return null;
 };
 
 /**
@@ -484,6 +486,8 @@ Address.prototype.fromWitness = function fromWitness(witness) {
     this.version = 0;
     return this;
   }
+
+  return null;
 };
 
 /**
@@ -506,6 +510,8 @@ Address.prototype.fromInputScript = function fromInputScript(script) {
     this.version = -1;
     return this;
   }
+
+  return null;
 };
 
 /**
@@ -824,11 +830,11 @@ Address.prototype.isUnknown = function isUnknown() {
  */
 
 Address.getHash = function getHash(data, enc, network) {
-  let hash;
-
   if (!data)
     throw new Error('Object is not an address.');
 
+  let hash;
+
   if (typeof data === 'string') {
     if (data.length === 40 || data.length === 64)
       return enc === 'hex' ? data : Buffer.from(data, 'hex');
diff --git a/lib/primitives/block.js b/lib/primitives/block.js
index 385bcba0..937aec2a 100644
--- a/lib/primitives/block.js
+++ b/lib/primitives/block.js
@@ -379,7 +379,7 @@ Block.prototype.getCommitmentHash = function getCommitmentHash(enc) {
     return null;
 
   const coinbase = this.txs[0];
-  let hash = null;
+  let hash;
 
   for (let i = coinbase.outputs.length - 1; i >= 0; i--) {
     const output = coinbase.outputs[i];
diff --git a/lib/primitives/input.js b/lib/primitives/input.js
index 6fa4932c..5178bcd7 100644
--- a/lib/primitives/input.js
+++ b/lib/primitives/input.js
@@ -123,7 +123,7 @@ Input.prototype.getType = function getType(coin) {
 
 Input.prototype.getRedeem = function getRedeem(coin) {
   if (this.isCoinbase())
-    return;
+    return null;
 
   if (!coin) {
     if (this.witness.isScripthashInput())
@@ -132,7 +132,7 @@ Input.prototype.getRedeem = function getRedeem(coin) {
     if (this.script.isScripthashInput())
       return this.script.getRedeem();
 
-    return;
+    return null;
   }
 
   let prev = coin.script;
@@ -159,12 +159,12 @@ Input.prototype.getRedeem = function getRedeem(coin) {
 
 Input.prototype.getSubtype = function getSubtype(coin) {
   if (this.isCoinbase())
-    return;
+    return null;
 
   const redeem = this.getRedeem(coin);
 
   if (!redeem)
-    return;
+    return null;
 
   const type = redeem.getType();
 
@@ -181,7 +181,7 @@ Input.prototype.getSubtype = function getSubtype(coin) {
 
 Input.prototype.getAddress = function getAddress(coin) {
   if (this.isCoinbase())
-    return;
+    return null;
 
   if (coin)
     return coin.getAddress();
@@ -202,7 +202,7 @@ Input.prototype.getHash = function getHash(enc) {
   const addr = this.getAddress();
 
   if (!addr)
-    return;
+    return null;
 
   return addr.getHash(enc);
 };
@@ -284,10 +284,9 @@ Input.prototype.toJSON = function toJSON(network, coin) {
  */
 
 Input.prototype.getJSON = function getJSON(network, coin) {
-  let addr;
-
   network = Network.get(network);
 
+  let addr;
   if (!coin) {
     addr = this.getAddress();
     if (addr)
diff --git a/lib/primitives/keyring.js b/lib/primitives/keyring.js
index 49e08a3b..9234e42b 100644
--- a/lib/primitives/keyring.js
+++ b/lib/primitives/keyring.js
@@ -58,13 +58,11 @@ function KeyRing(options, network) {
  */
 
 KeyRing.prototype.fromOptions = function fromOptions(options, network) {
-  let key = toKey(options);
-  const script = options.script;
-  const compressed = options.compressed;
-
   if (!network)
     network = options.network;
 
+  let key = toKey(options);
+
   if (Buffer.isBuffer(key))
     return this.fromKey(key, network);
 
@@ -86,10 +84,13 @@ KeyRing.prototype.fromOptions = function fromOptions(options, network) {
     this.nested = options.nested;
   }
 
-  if (script)
-    return this.fromScript(key, script, compressed, network);
+  const script = options.script;
+  const compress = options.compressed;
 
-  this.fromKey(key, compressed, network);
+  if (script)
+    return this.fromScript(key, script, compress, network);
+
+  return this.fromKey(key, compress, network);
 };
 
 /**
@@ -121,22 +122,22 @@ KeyRing.prototype.refresh = function refresh() {
  * Inject data from private key.
  * @private
  * @param {Buffer} key
- * @param {Boolean?} compressed
+ * @param {Boolean?} compress
  * @param {(NetworkType|Network)?} network
  */
 
-KeyRing.prototype.fromPrivate = function fromPrivate(key, compressed, network) {
+KeyRing.prototype.fromPrivate = function fromPrivate(key, compress, network) {
   assert(Buffer.isBuffer(key), 'Private key must be a buffer.');
   assert(secp256k1.privateKeyVerify(key), 'Not a valid private key.');
 
-  if (typeof compressed !== 'boolean') {
-    network = compressed;
-    compressed = null;
+  if (typeof compress !== 'boolean') {
+    network = compress;
+    compress = null;
   }
 
   this.network = Network.get(network);
   this.privateKey = key;
-  this.publicKey = secp256k1.publicKeyCreate(key, compressed !== false);
+  this.publicKey = secp256k1.publicKeyCreate(key, compress !== false);
 
   return this;
 };
@@ -144,13 +145,13 @@ KeyRing.prototype.fromPrivate = function fromPrivate(key, compressed, network) {
 /**
  * Instantiate keyring from a private key.
  * @param {Buffer} key
- * @param {Boolean?} compressed
+ * @param {Boolean?} compress
  * @param {(NetworkType|Network)?} network
  * @returns {KeyRing}
  */
 
-KeyRing.fromPrivate = function fromPrivate(key, compressed, network) {
-  return new KeyRing().fromPrivate(key, compressed, network);
+KeyRing.fromPrivate = function fromPrivate(key, compress, network) {
+  return new KeyRing().fromPrivate(key, compress, network);
 };
 
 /**
@@ -171,29 +172,31 @@ KeyRing.prototype.fromPublic = function fromPublic(key, network) {
 /**
  * Generate a keyring.
  * @private
+ * @param {Boolean?} compress
  * @param {(Network|NetworkType)?} network
  * @returns {KeyRing}
  */
 
-KeyRing.prototype.generate = function generate(compressed, network) {
-  if (typeof compressed !== 'boolean') {
-    network = compressed;
-    compressed = null;
+KeyRing.prototype.generate = function generate(compress, network) {
+  if (typeof compress !== 'boolean') {
+    network = compress;
+    compress = null;
   }
 
   const key = secp256k1.generatePrivateKey();
 
-  return this.fromKey(key, compressed, network);
+  return this.fromKey(key, compress, network);
 };
 
 /**
  * Generate a keyring.
+ * @param {Boolean?} compress
  * @param {(Network|NetworkType)?} network
  * @returns {KeyRing}
  */
 
-KeyRing.generate = function generate(compressed, network) {
-  return new KeyRing().generate(compressed, network);
+KeyRing.generate = function generate(compress, network) {
+  return new KeyRing().generate(compress, network);
 };
 
 /**
@@ -211,19 +214,20 @@ KeyRing.fromPublic = function fromPublic(key, network) {
  * Inject data from public key.
  * @private
  * @param {Buffer} privateKey
+ * @param {Boolean?} compress
  * @param {(NetworkType|Network)?} network
  */
 
-KeyRing.prototype.fromKey = function fromKey(key, compressed, network) {
+KeyRing.prototype.fromKey = function fromKey(key, compress, network) {
   assert(Buffer.isBuffer(key), 'Key must be a buffer.');
 
-  if (typeof compressed !== 'boolean') {
-    network = compressed;
-    compressed = null;
+  if (typeof compress !== 'boolean') {
+    network = compress;
+    compress = null;
   }
 
   if (key.length === 32)
-    return this.fromPrivate(key, compressed !== false, network);
+    return this.fromPrivate(key, compress !== false, network);
 
   return this.fromPublic(key, network);
 };
@@ -231,12 +235,13 @@ KeyRing.prototype.fromKey = function fromKey(key, compressed, network) {
 /**
  * Instantiate keyring from a public key.
  * @param {Buffer} publicKey
+ * @param {Boolean?} compress
  * @param {(NetworkType|Network)?} network
  * @returns {KeyRing}
  */
 
-KeyRing.fromKey = function fromKey(key, compressed, network) {
-  return new KeyRing().fromKey(key, compressed, network);
+KeyRing.fromKey = function fromKey(key, compress, network) {
+  return new KeyRing().fromKey(key, compress, network);
 };
 
 /**
@@ -244,18 +249,19 @@ KeyRing.fromKey = function fromKey(key, compressed, network) {
  * @private
  * @param {Buffer} key
  * @param {Script} script
+ * @param {Boolean?} compress
  * @param {(NetworkType|Network)?} network
  */
 
-KeyRing.prototype.fromScript = function fromScript(key, script, compressed, network) {
+KeyRing.prototype.fromScript = function fromScript(key, script, compress, network) {
   assert(script instanceof Script, 'Non-script passed into KeyRing.');
 
-  if (typeof compressed !== 'boolean') {
-    network = compressed;
-    compressed = null;
+  if (typeof compress !== 'boolean') {
+    network = compress;
+    compress = null;
   }
 
-  this.fromKey(key, compressed, network);
+  this.fromKey(key, compress, network);
   this.script = script;
 
   return this;
@@ -265,12 +271,13 @@ KeyRing.prototype.fromScript = function fromScript(key, script, compressed, netw
  * Instantiate keyring from script.
  * @param {Buffer} key
  * @param {Script} script
+ * @param {Boolean?} compress
  * @param {(NetworkType|Network)?} network
  * @returns {KeyRing}
  */
 
-KeyRing.fromScript = function fromScript(key, script, compressed, network) {
-  return new KeyRing().fromScript(key, script, compressed, network);
+KeyRing.fromScript = function fromScript(key, script, compress, network) {
+  return new KeyRing().fromScript(key, script, compress, network);
 };
 
 /**
@@ -336,16 +343,16 @@ KeyRing.prototype.fromSecret = function fromSecret(data, network) {
 
   const key = br.readBytes(32);
 
-  let compressed = false;
+  let compress = false;
 
   if (br.left() > 4) {
     assert(br.readU8() === 1, 'Bad compression flag.');
-    compressed = true;
+    compress = true;
   }
 
   br.verifyChecksum();
 
-  return this.fromPrivate(key, compressed, network);
+  return this.fromPrivate(key, compress, network);
 };
 
 /**
@@ -367,7 +374,7 @@ KeyRing.fromSecret = function fromSecret(data, network) {
 
 KeyRing.prototype.getPrivateKey = function getPrivateKey(enc) {
   if (!this.privateKey)
-    return;
+    return null;
 
   if (enc === 'base58')
     return this.toSecret();
@@ -410,7 +417,7 @@ KeyRing.prototype.getScript = function getScript() {
 
 KeyRing.prototype.getProgram = function getProgram() {
   if (!this.witness)
-    return;
+    return null;
 
   if (!this._program) {
     let program;
@@ -436,7 +443,7 @@ KeyRing.prototype.getProgram = function getProgram() {
 
 KeyRing.prototype.getNestedHash = function getNestedHash(enc) {
   if (!this.witness)
-    return;
+    return null;
 
   if (!this._nestedHash)
     this._nestedHash = this.getProgram().hash160();
@@ -454,7 +461,7 @@ KeyRing.prototype.getNestedHash = function getNestedHash(enc) {
 
 KeyRing.prototype.getNestedAddress = function getNestedAddress(enc) {
   if (!this.witness)
-    return;
+    return null;
 
   if (!this._nestedAddress) {
     const hash = this.getNestedHash();
@@ -491,7 +498,7 @@ KeyRing.prototype.getScriptHash = function getScriptHash(enc) {
 
 KeyRing.prototype.getScriptHash160 = function getScriptHash256(enc) {
   if (!this.script)
-    return;
+    return null;
 
   if (!this._scriptHash160)
     this._scriptHash160 = this.script.hash160();
@@ -509,7 +516,7 @@ KeyRing.prototype.getScriptHash160 = function getScriptHash256(enc) {
 
 KeyRing.prototype.getScriptHash256 = function getScriptHash256(enc) {
   if (!this.script)
-    return;
+    return null;
 
   if (!this._scriptHash256)
     this._scriptHash256 = this.script.sha256();
@@ -527,7 +534,7 @@ KeyRing.prototype.getScriptHash256 = function getScriptHash256(enc) {
 
 KeyRing.prototype.getScriptAddress = function getScriptAddress(enc) {
   if (!this.script)
-    return;
+    return null;
 
   if (!this._scriptAddress) {
     let addr;
@@ -602,8 +609,10 @@ KeyRing.prototype.getKeyAddress = function getKeyAddress(enc) {
 KeyRing.prototype.getHash = function getHash(enc) {
   if (this.nested)
     return this.getNestedHash(enc);
+
   if (this.script)
     return this.getScriptHash(enc);
+
   return this.getKeyHash(enc);
 };
 
@@ -616,8 +625,10 @@ KeyRing.prototype.getHash = function getHash(enc) {
 KeyRing.prototype.getAddress = function getAddress(enc) {
   if (this.nested)
     return this.getNestedAddress(enc);
+
   if (this.script)
     return this.getScriptAddress(enc);
+
   return this.getKeyAddress(enc);
 };
 
@@ -885,9 +896,9 @@ KeyRing.prototype.fromReader = function fromReader(br, network) {
   const key = br.readVarBytes();
 
   if (key.length === 32) {
-    const compressed = br.readU8() === 1;
+    const compress = br.readU8() === 1;
     this.privateKey = key;
-    this.publicKey = secp256k1.publicKeyCreate(key, compressed);
+    this.publicKey = secp256k1.publicKeyCreate(key, compress);
   } else {
     this.publicKey = key;
     assert(secp256k1.publicKeyVerify(key), 'Invalid public key.');
diff --git a/lib/primitives/memblock.js b/lib/primitives/memblock.js
index fc913a14..c72f0e67 100644
--- a/lib/primitives/memblock.js
+++ b/lib/primitives/memblock.js
@@ -109,25 +109,24 @@ MemBlock.prototype.getCoinbaseHeight = function getCoinbaseHeight() {
 
 MemBlock.prototype.parseCoinbaseHeight = function parseCoinbaseHeight() {
   const br = new BufferReader(this._raw, true);
-  let count;
 
   br.seek(80);
 
-  count = br.readVarint();
+  const txCount = br.readVarint();
 
-  if (count === 0)
+  if (txCount === 0)
     return -1;
 
   br.seek(4);
 
-  count = br.readVarint();
+  let inCount = br.readVarint();
 
-  if (count === 0) {
+  if (inCount === 0) {
     if (br.readU8() !== 0)
-      count = br.readVarint();
+      inCount = br.readVarint();
   }
 
-  if (count === 0)
+  if (inCount === 0)
     return -1;
 
   br.seek(36);
diff --git a/lib/primitives/merkleblock.js b/lib/primitives/merkleblock.js
index f397dcc9..07fcca76 100644
--- a/lib/primitives/merkleblock.js
+++ b/lib/primitives/merkleblock.js
@@ -228,7 +228,7 @@ MerkleBlock.prototype.extractTree = function extractTree() {
     }
 
     const left = traverse(height - 1, pos * 2);
-    let right = null;
+    let right;
 
     if (pos * 2 + 1 < width(height - 1)) {
       right = traverse(height - 1, pos * 2 + 1);
@@ -563,7 +563,7 @@ MerkleBlock.fromMatches = function fromMatches(block, matches) {
       return leaves[pos];
 
     const left = hash(height - 1, pos * 2, leaves);
-    let right = null;
+    let right;
 
     if (pos * 2 + 1 < width(height - 1))
       right = hash(height - 1, pos * 2 + 1, leaves);
diff --git a/lib/primitives/mtx.js b/lib/primitives/mtx.js
index f4a23d62..c145215e 100644
--- a/lib/primitives/mtx.js
+++ b/lib/primitives/mtx.js
@@ -733,22 +733,12 @@ MTX.prototype.signVector = function signVector(prev, vector, sig, ring) {
 
   // Multisig
   if (prev.isMultisig()) {
-    const keys = [];
-
-    // Grab `m` value (number of sigs required).
-    const m = prev.getSmall(0);
+    if (vector.getSmall(0) !== 0)
+      throw new Error('Input has not been templated.');
 
     // Grab `n` value (number of keys).
     const n = prev.getSmall(prev.length - 2);
 
-    // Grab the redeem script's keys to figure
-    // out where our key should go.
-    for (let i = 1; i < prev.length - 2; i++)
-      keys.push(prev.get(i));
-
-    if (vector.getSmall(0) !== 0)
-      throw new Error('Input has not been templated.');
-
     // Too many signature slots. Abort.
     if (vector.length - 1 > n)
       return false;
@@ -760,6 +750,9 @@ MTX.prototype.signVector = function signVector(prev, vector, sig, ring) {
         total++;
     }
 
+    // Grab `m` value (number of sigs required).
+    const m = prev.getSmall(0);
+
     // Signatures are already finalized.
     if (total === m && vector.length - 1 === m)
       return true;
@@ -769,6 +762,12 @@ MTX.prototype.signVector = function signVector(prev, vector, sig, ring) {
     while (vector.length - 1 < n)
       vector.push(opcodes.OP_0);
 
+    // Grab the redeem script's keys to figure
+    // out where our key should go.
+    const keys = [];
+    for (let i = 1; i < prev.length - 2; i++)
+      keys.push(prev.get(i));
+
     // Find the key index so we can place
     // the signature in the same index.
     let keyIndex = util.indexOf(keys, ring.publicKey);
@@ -919,17 +918,17 @@ MTX.prototype.isVectorSigned = function isVectorSigned(prev, vector) {
     // Grab `m` value (number of required sigs).
     const m = prev.getSmall(0);
 
+    // Ensure we have the correct number
+    // of required signatures.
+    if (vector.length - 1 !== m)
+      return false;
+
     // Ensure all members are signatures.
     for (let i = 1; i < vector.length; i++) {
       if (!Script.isSignature(vector.get(i)))
         return false;
     }
 
-    // Ensure we have the correct number
-    // of required signatures.
-    if (vector.length - 1 !== m)
-      return false;
-
     return true;
   }
 
@@ -1839,8 +1838,10 @@ function sortRandom(a, b) {
 function sortValue(a, b) {
   if (a.height === -1 && b.height !== -1)
     return 1;
+
   if (a.height !== -1 && b.height === -1)
     return -1;
+
   return b.value - a.value;
 }
 
diff --git a/lib/primitives/output.js b/lib/primitives/output.js
index 74cfeba1..1c76949f 100644
--- a/lib/primitives/output.js
+++ b/lib/primitives/output.js
@@ -144,8 +144,10 @@ Output.prototype.getAddress = function getAddress() {
 
 Output.prototype.getHash = function getHash(enc) {
   const addr = this.getAddress();
+
   if (!addr)
-    return;
+    return null;
+
   return addr.getHash(enc);
 };
 
@@ -204,12 +206,11 @@ Output.prototype.getJSON = function getJSON(network) {
 
 Output.prototype.getDustThreshold = function getDustThreshold(rate) {
   const scale = consensus.WITNESS_SCALE_FACTOR;
-  let size;
 
   if (this.script.isUnspendable())
     return 0;
 
-  size = this.getSize();
+  let size = this.getSize();
 
   if (this.script.isProgram()) {
     // 75% segwit discount applied to script size.
diff --git a/lib/primitives/tx.js b/lib/primitives/tx.js
index 19c67779..7e7fca5d 100644
--- a/lib/primitives/tx.js
+++ b/lib/primitives/tx.js
@@ -303,7 +303,6 @@ TX.prototype.frame = function frame() {
   }
 
   let raw;
-
   if (this.hasWitness())
     raw = this.frameWitness();
   else
@@ -1116,14 +1115,13 @@ TX.prototype.getAddresses = function getAddresses(view) {
  */
 
 TX.prototype.getInputHashes = function getInputHashes(view, enc) {
-  const hashes = [];
-
   if (enc === 'hex') {
     const [, table] = this._getInputAddresses(view);
     return Object.keys(table);
   }
 
   const addrs = this.getInputAddresses(view);
+  const hashes = [];
 
   for (const addr of addrs)
     hashes.push(addr.getHash());
@@ -1137,14 +1135,13 @@ TX.prototype.getInputHashes = function getInputHashes(view, enc) {
  */
 
 TX.prototype.getOutputHashes = function getOutputHashes(enc) {
-  const hashes = [];
-
   if (enc === 'hex') {
     const [, table] = this._getOutputAddresses();
     return Object.keys(table);
   }
 
   const addrs = this.getOutputAddresses();
+  const hashes = [];
 
   for (const addr of addrs)
     hashes.push(addr.getHash());
@@ -1159,14 +1156,13 @@ TX.prototype.getOutputHashes = function getOutputHashes(enc) {
  */
 
 TX.prototype.getHashes = function getHashes(view, enc) {
-  const hashes = [];
-
   if (enc === 'hex') {
     const [, table] = this._getAddresses(view);
     return Object.keys(table);
   }
 
   const addrs = this.getAddresses(view);
+  const hashes = [];
 
   for (const addr of addrs)
     hashes.push(addr.getHash());
@@ -1407,9 +1403,6 @@ TX.prototype.isSane = function isSane() {
  */
 
 TX.prototype.checkSanity = function checkSanity() {
-  const prevout = new Set();
-  let total = 0;
-
   if (this.inputs.length === 0)
     return [false, 'bad-txns-vin-empty', 100];
 
@@ -1419,6 +1412,8 @@ TX.prototype.checkSanity = function checkSanity() {
   if (this.getBaseSize() > consensus.MAX_BLOCK_SIZE)
     return [false, 'bad-txns-oversize', 100];
 
+  let total = 0;
+
   for (const output of this.outputs) {
     if (output.value < 0)
       return [false, 'bad-txns-vout-negative', 100];
@@ -1432,10 +1427,14 @@ TX.prototype.checkSanity = function checkSanity() {
       return [false, 'bad-txns-txouttotal-toolarge', 100];
   }
 
+  const prevout = new Set();
+
   for (const input of this.inputs) {
     const key = input.prevout.toKey();
+
     if (prevout.has(key))
       return [false, 'bad-txns-inputs-duplicate', 100];
+
     prevout.add(key);
   }
 
@@ -1479,8 +1478,6 @@ TX.prototype.isStandard = function isStandard() {
  */
 
 TX.prototype.checkStandard = function checkStandard() {
-  let nulldata = 0;
-
   if (this.version < 1 || this.version > policy.MAX_TX_VERSION)
     return [false, 'version', 0];
 
@@ -1495,6 +1492,8 @@ TX.prototype.checkStandard = function checkStandard() {
       return [false, 'scriptsig-not-pushonly', 0];
   }
 
+  let nulldata = 0;
+
   for (const output of this.outputs) {
     if (!output.script.isStandard())
       return [false, 'scriptpubkey', 0];
@@ -1706,10 +1705,10 @@ TX.prototype.verifyInputs = function verifyInputs(view, height) {
  */
 
 TX.prototype.checkInputs = function checkInputs(view, height) {
-  let total = 0;
-
   assert(typeof height === 'number');
 
+  let total = 0;
+
   for (const {prevout} of this.inputs) {
     let coin = view.getEntry(prevout);
 
@@ -1781,16 +1780,16 @@ TX.prototype.getModifiedSize = function getModifiedSize(size) {
  */
 
 TX.prototype.getPriority = function getPriority(view, height, size) {
-  let sum = 0;
-
   assert(typeof height === 'number', 'Must pass in height.');
 
   if (this.isCoinbase())
-    return sum;
+    return 0;
 
   if (size == null)
     size = this.getVirtualSize();
 
+  let sum = 0;
+
   for (const {prevout} of this.inputs) {
     const coin = view.getOutput(prevout);
 
@@ -1818,10 +1817,10 @@ TX.prototype.getPriority = function getPriority(view, height, size) {
  */
 
 TX.prototype.getChainValue = function getChainValue(view) {
-  let value = 0;
-
   if (this.isCoinbase())
-    return value;
+    return 0;
+
+  let value = 0;
 
   for (const {prevout} of this.inputs) {
     const coin = view.getOutput(prevout);
@@ -1829,9 +1828,9 @@ TX.prototype.getChainValue = function getChainValue(view) {
     if (!coin)
       continue;
 
-    const coinHeight = view.getHeight(prevout);
+    const height = view.getHeight(prevout);
 
-    if (coinHeight === -1)
+    if (height === -1)
       continue;
 
     value += coin.value;
@@ -1917,11 +1916,11 @@ TX.prototype.getRate = function getRate(view, size) {
  */
 
 TX.prototype.getPrevout = function getPrevout() {
-  const prevout = Object.create(null);
-
   if (this.isCoinbase())
     return [];
 
+  const prevout = Object.create(null);
+
   for (const input of this.inputs)
     prevout[input.prevout.hash] = true;
 
diff --git a/lib/protocol/network.js b/lib/protocol/network.js
index 7330299e..fd973947 100644
--- a/lib/protocol/network.js
+++ b/lib/protocol/network.js
@@ -116,8 +116,10 @@ Network.prototype._init = function _init() {
 
 Network.prototype.byBit = function byBit(bit) {
   const index = util.binarySearch(this.deploys, bit, cmpBit);
+
   if (index === -1)
     return null;
+
   return this.deploys[index];
 };
 
diff --git a/lib/protocol/policy.js b/lib/protocol/policy.js
index 8d9ffecc..8a3652c3 100644
--- a/lib/protocol/policy.js
+++ b/lib/protocol/policy.js
@@ -217,8 +217,6 @@ exports.BLOCK_PRIORITY_THRESHOLD = exports.FREE_THRESHOLD;
  */
 
 exports.getMinFee = function getMinFee(size, rate) {
-  let fee;
-
   if (rate == null)
     rate = exports.MIN_RELAY;
 
@@ -228,7 +226,7 @@ exports.getMinFee = function getMinFee(size, rate) {
   if (size === 0)
     return 0;
 
-  fee = Math.floor(rate * size / 1000);
+  let fee = Math.floor(rate * size / 1000);
 
   if (fee === 0 && rate > 0)
     fee = rate;
@@ -246,8 +244,6 @@ exports.getMinFee = function getMinFee(size, rate) {
  */
 
 exports.getRoundFee = function getRoundFee(size, rate) {
-  let fee;
-
   if (rate == null)
     rate = exports.MIN_RELAY;
 
@@ -257,7 +253,7 @@ exports.getRoundFee = function getRoundFee(size, rate) {
   if (size === 0)
     return 0;
 
-  fee = rate * Math.ceil(size / 1000);
+  let fee = rate * Math.ceil(size / 1000);
 
   if (fee === 0 && rate > 0)
     fee = rate;
diff --git a/lib/protocol/timedata.js b/lib/protocol/timedata.js
index 2dfe1b5a..8d8a30e7 100644
--- a/lib/protocol/timedata.js
+++ b/lib/protocol/timedata.js
@@ -49,14 +49,14 @@ util.inherits(TimeData, EventEmitter);
  */
 
 TimeData.prototype.add = function add(id, time) {
-  const sample = time - util.now();
-
   if (this.samples.length >= this.limit)
     return;
 
   if (this.known.has(id))
     return;
 
+  const sample = time - util.now();
+
   this.known.set(id, sample);
 
   util.binaryInsert(this.samples, sample, compare);
diff --git a/lib/script/common.js b/lib/script/common.js
index 4a51265b..227f0dae 100644
--- a/lib/script/common.js
+++ b/lib/script/common.js
@@ -555,50 +555,49 @@ exports.formatCode = function formatCode(code) {
   const out = [];
 
   for (const op of code) {
-    const data = op.data;
-    let value = op.value;
+    if (op.data) {
+      // Direct push
+      if (!exports.opcodesByVal[op.value]) {
+        let size = op.value.toString(16);
+        if (size.length < 2)
+          size = '0' + size;
+        out.push(`0x${size} 0x${op.data.toString('hex')}`);
+        continue;
+      }
 
-    if (data) {
-      let size = data.length.toString(16);
+      // Pushdatas
+      const symbol = exports.opcodesByVal[op.value];
+
+      let size = op.data.length.toString(16);
 
       while (size.length % 2 !== 0)
         size = '0' + size;
 
-      if (!exports.opcodesByVal[value]) {
-        value = value.toString(16);
-        if (value.length < 2)
-          value = '0' + value;
-        value = `0x${value} 0x${data.toString('hex')}`;
-        out.push(value);
-        continue;
-      }
+      out.push(`${symbol} 0x${size} 0x${op.data.toString('hex')}`);
 
-      value = exports.opcodesByVal[value];
-      value = `${value} 0x${size} 0x${data.toString('hex')}`;
-      out.push(value);
       continue;
     }
 
-    assert(typeof value === 'number');
-
-    if (exports.opcodesByVal[value]) {
-      value = exports.opcodesByVal[value];
-      out.push(value);
+    // Opcodes
+    if (exports.opcodesByVal[op.value]) {
+      const symbol = exports.opcodesByVal[op.value];
+      out.push(symbol);
       continue;
     }
 
-    if (value === -1) {
+    // Bad push
+    if (op.value === -1) {
       out.push('OP_INVALIDOPCODE');
       break;
     }
 
-    value = value.toString(16);
+    // Unknown opcodes
+    let symbol = op.value.toString(16);
 
-    if (value.length < 2)
-      value = '0' + value;
+    if (symbol.length < 2)
+      symbol = '0' + symbol;
 
-    value = `0x${value}`;
-    out.push(value);
+    out.push(`0x${symbol}`);
   }
 
   return out.join(' ');
@@ -646,29 +645,28 @@ exports.formatItem = function formatItem(data, decode) {
  */
 
 exports.formatASM = function formatASM(code, decode) {
+  if (code.length > 0) {
+    if (code[0].value === exports.opcodes.OP_RETURN)
+      decode = false;
+  }
+
   const out = [];
 
-  if (code.length > 0 && code[0].value === exports.opcodes.OP_RETURN)
-    decode = false;
-
   for (const op of code) {
-    let data = op.data;
-    let value = op.value;
-
-    if (value === -1) {
+    if (op.value === -1) {
       out.push('[error]');
       break;
     }
 
-    if (data) {
-      data = exports.formatItem(data, decode);
+    if (op.data) {
+      const data = exports.formatItem(op.data, decode);
       out.push(data);
       continue;
     }
 
-    value = exports.opcodesByVal[value] || 'OP_UNKNOWN';
+    const symbol = exports.opcodesByVal[op.value] || 'OP_UNKNOWN';
 
-    out.push(value);
+    out.push(symbol);
   }
 
   return out.join(' ');
diff --git a/lib/script/opcode.js b/lib/script/opcode.js
index 49481f30..8eae5dc5 100644
--- a/lib/script/opcode.js
+++ b/lib/script/opcode.js
@@ -186,7 +186,6 @@ Opcode.prototype.getSize = function getSize() {
 
 Opcode.prototype.fromReader = function fromReader(br) {
   const op = br.readU8();
-  let size;
 
   if (op >= 0x01 && op <= 0x4b) {
     if (br.left() < op) {
@@ -199,6 +198,8 @@ Opcode.prototype.fromReader = function fromReader(br) {
     return this;
   }
 
+  let size;
+
   switch (op) {
     case opcodes.OP_PUSHDATA1:
       if (br.left() < 1) {
diff --git a/lib/script/script.js b/lib/script/script.js
index c82d5b2b..616b9fd2 100644
--- a/lib/script/script.js
+++ b/lib/script/script.js
@@ -411,11 +411,11 @@ Script.fromJSON = function fromJSON(json) {
  */
 
 Script.prototype.getSubscript = function getSubscript(lastSep) {
-  const code = [];
-
   if (lastSep === 0)
     return this.clone();
 
+  const code = [];
+
   for (let i = lastSep; i < this.code.length; i++) {
     const op = this.code[i];
 
@@ -483,25 +483,26 @@ Script.prototype.removeSeparators = function removeSeparators() {
  */
 
 Script.prototype.execute = function execute(stack, flags, tx, index, value, version) {
-  const state = [];
-  const alt = [];
-  let lastSep = 0;
-  let opCount = 0;
-  let negate = 0;
-  let minimal = false;
-
   if (flags == null)
     flags = Script.flags.STANDARD_VERIFY_FLAGS;
 
   if (version == null)
     version = 0;
 
-  if (flags & Script.flags.VERIFY_MINIMALDATA)
-    minimal = true;
-
   if (this.getSize() > consensus.MAX_SCRIPT_SIZE)
     throw new ScriptError('SCRIPT_SIZE');
 
+  const state = [];
+  const alt = [];
+
+  let lastSep = 0;
+  let opCount = 0;
+  let negate = 0;
+  let minimal = false;
+
+  if (flags & Script.flags.VERIFY_MINIMALDATA)
+    minimal = true;
+
   for (let ip = 0; ip < this.code.length; ip++) {
     const op = this.code[ip];
 
@@ -1667,15 +1668,15 @@ Script.fromCommitment = function fromCommitment(hash, flags) {
 
 Script.prototype.getRedeem = function getRedeem() {
   if (this.code.length === 0)
-    return;
+    return null;
 
   if (!this.isPushOnly())
-    return;
+    return null;
 
   const redeem = this.code[this.code.length - 1];
 
   if (!redeem.data)
-    return;
+    return null;
 
   return Script.fromRaw(redeem.data);
 };
@@ -1987,7 +1988,7 @@ Script.prototype.isCommitment = function isCommitment() {
 
 Script.prototype.getCommitmentHash = function getCommitmentHash() {
   if (!this.isCommitment())
-    return;
+    return null;
 
   return this.raw.slice(6, 38);
 };
@@ -2021,7 +2022,7 @@ Script.prototype.isProgram = function isProgram() {
 
 Script.prototype.toProgram = function toProgram() {
   if (!this.isProgram())
-    return;
+    return null;
 
   const version = common.getSmall(this.raw[0]);
   const data = this.raw.slice(2);
@@ -2671,12 +2672,11 @@ Script.prototype.fromString = function fromString(code) {
   if (code.length === 0)
     return this;
 
-  code = code.split(/\s+/);
-
+  const items = code.split(/\s+/);
   const bw = new BufferWriter();
 
-  for (let op of code) {
-    let symbol = op;
+  for (const item of items) {
+    let symbol = item;
 
     if (!util.isUpperCase(symbol))
       symbol = symbol.toUpperCase();
@@ -2684,29 +2684,37 @@ Script.prototype.fromString = function fromString(code) {
     if (!util.startsWith(symbol, 'OP_'))
       symbol = `OP_${symbol}`;
 
-    if (opcodes[symbol] == null) {
-      if (op[0] === '\'') {
-        assert(op[op.length - 1] === '\'', 'Unknown opcode.');
-        op = op.slice(1, -1);
-        op = Opcode.fromString(op);
+    const value = opcodes[symbol];
+
+    if (value == null) {
+      if (item[0] === '\'') {
+        assert(item[item.length - 1] === '\'', 'Unknown opcode.');
+        const str = item.slice(1, -1);
+        const op = Opcode.fromString(str);
         bw.writeBytes(op.toRaw());
         continue;
       }
-      if (/^-?\d+$/.test(op)) {
-        op = new BN(op, 10);
-        op = Opcode.fromNumber(op);
+
+      if (/^-?\d+$/.test(item)) {
+        const num = new BN(item, 10);
+        const op = Opcode.fromNumber(num);
         bw.writeBytes(op.toRaw());
         continue;
       }
-      assert(op.indexOf('0x') === 0, 'Unknown opcode.');
-      op = op.substring(2);
-      assert(util.isHex(op), 'Unknown opcode.');
-      op = Buffer.from(op, 'hex');
-      bw.writeBytes(op);
+
+      assert(item.indexOf('0x') === 0, 'Unknown opcode.');
+
+      const str = item.substring(2);
+      const data = Buffer.from(str, 'hex');
+
+      assert(data.length === str.length / 2, 'Unknown opcode.');
+
+      bw.writeBytes(data);
+
       continue;
     }
 
-    bw.writeU8(opcodes[symbol]);
+    bw.writeU8(value);
   }
 
   return this.fromRaw(bw.render());
@@ -2738,8 +2746,6 @@ Script.fromString = function fromString(code) {
  */
 
 Script.verify = function verify(input, witness, output, tx, i, value, flags) {
-  let hadWitness = false;
-
   if (flags == null)
     flags = Script.flags.STANDARD_VERIFY_FLAGS;
 
@@ -2766,6 +2772,8 @@ Script.verify = function verify(input, witness, output, tx, i, value, flags) {
   if (stack.length === 0 || !Script.bool(stack.top(-1)))
     throw new ScriptError('EVAL_FALSE');
 
+  let hadWitness = false;
+
   if ((flags & Script.flags.VERIFY_WITNESS) && output.isProgram()) {
     hadWitness = true;
 
@@ -2852,12 +2860,13 @@ Script.verify = function verify(input, witness, output, tx, i, value, flags) {
 
 Script.verifyProgram = function verifyProgram(witness, output, flags, tx, i, value) {
   const program = output.toProgram();
-  const stack = witness.toStack();
-  let redeem;
 
   assert(program, 'verifyProgram called on non-witness-program.');
   assert((flags & Script.flags.VERIFY_WITNESS) !== 0);
 
+  const stack = witness.toStack();
+  let redeem;
+
   if (program.version === 0) {
     if (program.data.length === 32) {
       if (stack.length === 0)
@@ -2923,11 +2932,6 @@ Script.verifyProgram = function verifyProgram(witness, output, flags, tx, i, val
  */
 
 Script.verifyMast = function verifyMast(program, stack, output, flags, tx, i, value) {
-  let mastRoot = new BufferWriter();
-  let scriptRoot = new BufferWriter();
-  let scripts = new BufferWriter();
-  let version = 0;
-
   assert(program.version === 1);
   assert((flags & Script.flags.VERIFY_MAST) !== 0);
 
@@ -2943,11 +2947,14 @@ Script.verifyMast = function verifyMast(program, stack, output, flags, tx, i, va
     throw new ScriptError('INVALID_MAST_STACK');
 
   let ops = subscripts;
+  let scriptRoot = new BufferWriter();
   scriptRoot.writeU8(subscripts);
 
   if (metadata[metadata.length - 1] === 0x00)
     throw new ScriptError('INVALID_MAST_STACK');
 
+  let version = 0;
+
   for (let j = 1; j < metadata.length; j++)
     version |= metadata[i] << 8 * (j - 1);
 
@@ -2959,6 +2966,7 @@ Script.verifyMast = function verifyMast(program, stack, output, flags, tx, i, va
       throw new ScriptError('DISCOURAGE_UPGRADABLE_WITNESS_PROGRAM');
   }
 
+  let mastRoot = new BufferWriter();
   mastRoot.writeU32(version);
 
   const pathdata = stack.top(-2);
@@ -3004,6 +3012,7 @@ Script.verifyMast = function verifyMast(program, stack, output, flags, tx, i, va
       throw new ScriptError('INVALID_MAST_STACK');
   }
 
+  let scripts = new BufferWriter();
   scripts.writeBytes(output.raw);
 
   for (let j = 0; j < subscripts; j++) {
diff --git a/lib/script/scriptnum.js b/lib/script/scriptnum.js
index 32cdcef8..89b71fc2 100644
--- a/lib/script/scriptnum.js
+++ b/lib/script/scriptnum.js
@@ -162,12 +162,11 @@ ScriptNum.prototype.toJSON = function toJSON() {
 };
 
 ScriptNum.prototype.fromString = function fromString(str, base) {
-  let nonzero = 0;
-  let negative = false;
-
   if (!base)
     base = 10;
 
+  let negative = false;
+
   if (str[0] === '-') {
     assert(str.length > 1, 'Non-numeric string passed.');
     str = str.substring(1);
@@ -179,6 +178,7 @@ ScriptNum.prototype.fromString = function fromString(str, base) {
   this.value = 0;
 
   if (base === 10 || base === 'dec') {
+    let nonzero = 0;
     for (let i = 0; i < str.length; i++) {
       let ch = str[i];
 
@@ -204,6 +204,7 @@ ScriptNum.prototype.fromString = function fromString(str, base) {
   }
 
   if (base === 16 || base === 'hex') {
+    let nonzero = 0;
     for (let i = 0; i < str.length; i++) {
       let ch = str[i];
 
@@ -320,20 +321,20 @@ ScriptNum.fromRaw = function fromRaw(data, minimal, limit) {
 
 ScriptNum.prototype.toRaw = function toRaw() {
   let value = this.value;
-  let negative = false;
-  let offset, size;
 
   // Zeroes are always empty arrays.
   if (value === 0)
     return EMPTY_ARRAY;
 
   // Need to append sign bit.
+  let negative = false;
   if (value < 0) {
     negative = true;
     value = -value;
   }
 
   // Gauge buffer size.
+  let offset, size;
   if (value <= 0xff) {
     offset = (value & 0x80) ? 1 : 0;
     size = 1;
diff --git a/lib/script/stack.js b/lib/script/stack.js
index 0cfddacf..753353de 100644
--- a/lib/script/stack.js
+++ b/lib/script/stack.js
@@ -183,7 +183,7 @@ Stack.prototype.remove = function remove(i) {
     i = this.items.length + i;
 
   if (i >= this.items.length)
-    return;
+    return undefined;
 
   return this.items.splice(i, 1)[0];
 };
diff --git a/lib/script/witness.js b/lib/script/witness.js
index 7af3aa64..6e4defa3 100644
--- a/lib/script/witness.js
+++ b/lib/script/witness.js
@@ -78,13 +78,11 @@ Witness.prototype.__defineSetter__('length', function(length) {
 Witness.prototype.fromOptions = function fromOptions(options) {
   assert(options, 'Witness data is required.');
 
-  let items = options.items;
+  if (Array.isArray(options))
+    return this.fromArray(options);
 
-  if (!items)
-    items = options;
-
-  if (items)
-    this.fromArray(items);
+  if (options.items)
+    return this.fromArray(options.items);
 
   return this;
 };
@@ -294,12 +292,12 @@ Witness.prototype.test = function test(filter) {
 
 Witness.prototype.getRedeem = function getRedeem() {
   if (this.items.length === 0)
-    return;
+    return null;
 
   const redeem = this.items[this.items.length - 1];
 
   if (!redeem)
-    return;
+    return null;
 
   return Script.fromRaw(redeem);
 };
@@ -496,8 +494,10 @@ Witness.prototype.getSmall = function getSmall(i) {
 
 Witness.prototype.getNumber = function getNumber(i) {
   const item = this.items[i];
+
   if (!item || item.length > 5)
-    return;
+    return null;
+
   return common.num(item, false, 5);
 };
 
@@ -509,8 +509,10 @@ Witness.prototype.getNumber = function getNumber(i) {
 
 Witness.prototype.getString = function getString(i) {
   const item = this.items[i];
+
   if (!item)
-    return;
+    return null;
+
   return item.toString('utf8');
 };
 
diff --git a/lib/utils/asn1.js b/lib/utils/asn1.js
index 26841774..8dae485b 100644
--- a/lib/utils/asn1.js
+++ b/lib/utils/asn1.js
@@ -123,8 +123,10 @@ ASN1.readSeq = function readSeq(br) {
 
 ASN1.implicit = function implicit(br, type) {
   const tag = ASN1.readTag(br);
+
   if (tag.type !== type)
     throw new Error(`Unexpected tag: ${tag.type}.`);
+
   return tag;
 };
 
@@ -138,10 +140,12 @@ ASN1.implicit = function implicit(br, type) {
 ASN1.explicit = function explicit(br, type) {
   const offset = br.offset;
   const tag = ASN1.readTag(br);
+
   if (tag.type !== type) {
     br.offset = offset;
     return false;
   }
+
   return true;
 };
 
@@ -158,15 +162,15 @@ ASN1.seq = function seq(br) {
 /**
  * Read implicit int.
  * @param {BufferReader} br
- * @param {Boolean?} readNum
+ * @param {Boolean?} cast
  * @returns {Buffer|Number}
  */
 
-ASN1.readInt = function readInt(br, readNum) {
+ASN1.readInt = function readInt(br, cast) {
   const tag = ASN1.implicit(br, 0x02);
   const num = br.readBytes(tag.size);
 
-  if (readNum)
+  if (cast)
     return num.readUIntBE(0, num.length);
 
   return num;
@@ -183,6 +187,7 @@ ASN1.readInt = function readInt(br, readNum) {
 ASN1.readExplicitInt = function readExplicitInt(br, type, readNum) {
   if (!ASN1.explicit(br, type))
     return -1;
+
   return ASN1.readInt(br, readNum);
 };
 
@@ -210,7 +215,7 @@ ASN1.readString = function readString(br) {
   switch (tag.type) {
     case 0x03: { // bitstr
       const str = br.readBytes(tag.size);
-      return ASN1.alignBitstr(str);
+      return ASN1.alignBitstr(str).toString('utf8');
     }
     // Note:
     // Fuck all these.
diff --git a/lib/utils/asyncemitter.js b/lib/utils/asyncemitter.js
index 78e99a9c..32d0654c 100644
--- a/lib/utils/asyncemitter.js
+++ b/lib/utils/asyncemitter.js
@@ -183,7 +183,7 @@ AsyncEmitter.prototype.listeners = function listeners(type) {
   const listeners = this._events[type];
 
   if (!listeners)
-    return result;
+    return [];
 
   const result = [];
 
@@ -236,7 +236,7 @@ AsyncEmitter.prototype.emit = function emit(type) {
     return;
   }
 
-  let args = null;
+  let args;
 
   for (let i = 0; i < listeners.length; i++) {
     const listener = listeners[i];
@@ -299,7 +299,7 @@ AsyncEmitter.prototype.fire = async function fire(type) {
     return;
   }
 
-  let args = null;
+  let args;
 
   for (let i = 0; i < listeners.length; i++) {
     const listener = listeners[i];
diff --git a/lib/utils/asyncobject.js b/lib/utils/asyncobject.js
index 86089291..eb11befb 100644
--- a/lib/utils/asyncobject.js
+++ b/lib/utils/asyncobject.js
@@ -197,7 +197,7 @@ AsyncObject.prototype.fireHook = async function fireHook(type) {
   if (!listeners || listeners.length === 0)
     return;
 
-  let args = null;
+  let args;
 
   for (const handler of listeners) {
     switch (arguments.length) {
diff --git a/lib/utils/base32.js b/lib/utils/base32.js
index 8d344523..a70f4f92 100644
--- a/lib/utils/base32.js
+++ b/lib/utils/base32.js
@@ -27,10 +27,9 @@ exports.encode = function encode(data) {
   let str = '';
   let mode = 0;
   let left = 0;
-  let i, ch;
 
-  for (i = 0; i < data.length; i++) {
-    ch = data[i];
+  for (let i = 0; i < data.length; i++) {
+    const ch = data[i];
     switch (mode) {
       case 0:
         str += base32[ch >>> 3];
@@ -64,7 +63,7 @@ exports.encode = function encode(data) {
 
   if (mode > 0) {
     str += base32[left];
-    for (i = 0; i < padding[mode]; i++)
+    for (let i = 0; i < padding[mode]; i++)
       str += '=';
   }
 
@@ -82,10 +81,10 @@ exports.decode = function decode(str) {
   let mode = 0;
   let left = 0;
   let j = 0;
-  let i, ch;
+  let i;
 
   for (i = 0; i < str.length; i++) {
-    ch = unbase32[str[i]];
+    const ch = unbase32[str[i]];
 
     if (ch == null)
       break;
diff --git a/lib/utils/bech32.js b/lib/utils/bech32.js
index 82c87799..b4d08df6 100644
--- a/lib/utils/bech32.js
+++ b/lib/utils/bech32.js
@@ -74,7 +74,6 @@ function polymod(pre) {
  */
 
 function serialize(hrp, data) {
-  let str = '';
   let chk = 1;
   let i;
 
@@ -92,6 +91,8 @@ function serialize(hrp, data) {
 
   chk = polymod(chk);
 
+  let str = '';
+
   for (let i = 0; i < hrp.length; i++) {
     const ch = hrp.charCodeAt(i);
     chk = polymod(chk) ^ (ch & 0x1f);
diff --git a/lib/utils/bloom.js b/lib/utils/bloom.js
index 936d7d33..3d84d83b 100644
--- a/lib/utils/bloom.js
+++ b/lib/utils/bloom.js
@@ -262,8 +262,8 @@ Bloom.fromRate = function fromRate(items, rate, update) {
   assert(typeof rate === 'number', '`rate` must be a number.');
   assert(rate >= 0 && rate <= 1, '`rate` must be between 0.0 and 1.0.');
 
-  let size = (-1 / LN2SQUARED * items * Math.log(rate)) | 0;
-  size = Math.max(8, size);
+  const bits = (-1 / LN2SQUARED * items * Math.log(rate)) | 0;
+  const size = Math.max(8, bits);
 
   if (update !== -1) {
     assert(size <= Bloom.MAX_BLOOM_FILTER_SIZE * 8,
diff --git a/lib/utils/co.js b/lib/utils/co.js
index 9fad1b29..b1d44ea5 100644
--- a/lib/utils/co.js
+++ b/lib/utils/co.js
@@ -21,6 +21,8 @@ const assert = require('assert');
 
 function exec(gen) {
   return new Promise((resolve, reject) => {
+    /* eslint no-use-before-define: "off" */
+
     const step = (value, rejection) => {
       let next;
 
diff --git a/lib/utils/encoding.js b/lib/utils/encoding.js
index 245b096e..d56d7e06 100644
--- a/lib/utils/encoding.js
+++ b/lib/utils/encoding.js
@@ -899,12 +899,12 @@ encoding.readVarint2BN = function readVarint2BN(data, off) {
  */
 
 encoding.writeVarint2BN = function writeVarint2BN(dst, num, off) {
-  const tmp = [];
-  let len = 0;
-
   if (num.bitLength() <= 53)
     return encoding.writeVarint2(dst, num.toNumber());
 
+  const tmp = [];
+  let len = 0;
+
   for (;;) {
     tmp[len] = (num.words[0] & 0x7f) | (len ? 0x80 : 0x00);
     if (num.cmpn(0x7f) <= 0)
@@ -929,13 +929,13 @@ encoding.writeVarint2BN = function writeVarint2BN(dst, num, off) {
  */
 
 encoding.sizeVarint2BN = function sizeVarint2BN(num) {
-  let size = 0;
-
   if (num.bitLength() <= 53)
     return encoding.sizeVarint(num.toNumber());
 
   num = num.clone();
 
+  let size = 0;
+
   for (;;) {
     size++;
     if (num.cmpn(0x7f) <= 0)
diff --git a/lib/utils/fs.js b/lib/utils/fs.js
index bc0c02c8..28f71067 100644
--- a/lib/utils/fs.js
+++ b/lib/utils/fs.js
@@ -85,11 +85,11 @@ exports.writeFile = co.promisify(fs.writeFile);
 exports.writeFileSync = fs.writeFileSync;
 
 exports.mkdirpSync = function mkdirpSync(dir, mode) {
-  let [path, parts] = getParts(dir);
-
   if (mode == null)
     mode = 0o750;
 
+  let [path, parts] = getParts(dir);
+
   for (const part of parts) {
     path += part;
 
@@ -109,11 +109,11 @@ exports.mkdirpSync = function mkdirpSync(dir, mode) {
 };
 
 exports.mkdirp = async function mkdirp(dir, mode) {
-  let [path, parts] = getParts(dir);
-
   if (mode == null)
     mode = 0o750;
 
+  let [path, parts] = getParts(dir);
+
   for (const part of parts) {
     path += part;
 
@@ -138,6 +138,7 @@ function getParts(path) {
   path = path.replace(/\/+\.?$/, '');
 
   const parts = path.split(/\/+/);
+
   let root = '';
 
   if (process.platform === 'win32') {
diff --git a/lib/utils/gcs.js b/lib/utils/gcs.js
index bb1f0f71..29e7efaa 100644
--- a/lib/utils/gcs.js
+++ b/lib/utils/gcs.js
@@ -63,12 +63,11 @@ GCSFilter.prototype.match = function match(key, data) {
 };
 
 GCSFilter.prototype.matchAny = function matchAny(key, items) {
+  assert(items.length > 0);
+
   const br = new BitReader(this.data);
   const last1 = new Int64(0);
   const values = [];
-  let i, last2;
-
-  assert(items.length > 0);
 
   for (const item of items) {
     const hash = siphash(item, key).imod(this.m);
@@ -77,8 +76,8 @@ GCSFilter.prototype.matchAny = function matchAny(key, items) {
 
   values.sort(compare);
 
-  last2 = values[0];
-  i = 1;
+  let last2 = values[0];
+  let i = 1;
 
   for (;;) {
     const cmp = last1.cmp(last2);
@@ -160,10 +159,6 @@ GCSFilter.prototype.toRaw = function toRaw() {
 };
 
 GCSFilter.prototype.fromItems = function fromItems(P, key, items) {
-  const bw = new BitWriter();
-  let last = new Int64(0);
-  const values = [];
-
   assert(typeof P === 'number' && isFinite(P));
   assert(P >= 0 && P <= 32);
 
@@ -178,6 +173,8 @@ GCSFilter.prototype.fromItems = function fromItems(P, key, items) {
   this.p = P;
   this.m = Int64(this.n).ishln(this.p);
 
+  const values = [];
+
   for (const item of items) {
     assert(Buffer.isBuffer(item));
     const hash = siphash(item, key).imod(this.m);
@@ -186,6 +183,9 @@ GCSFilter.prototype.fromItems = function fromItems(P, key, items) {
 
   values.sort(compare);
 
+  const bw = new BitWriter();
+  let last = new Int64(0);
+
   for (const hash of values) {
     const rem = hash.sub(last).imaskn(this.p);
     const value = hash.sub(last).isub(rem).ishrn(this.p);
@@ -439,8 +439,6 @@ BitReader.prototype.readBit = function readBit() {
 };
 
 BitReader.prototype.readByte = function readByte() {
-  let ch;
-
   if (this.pos >= this.stream.length)
     throw new Error('EOF');
 
@@ -454,12 +452,12 @@ BitReader.prototype.readByte = function readByte() {
   }
 
   if (this.remain === 8) {
-    ch = this.stream[this.pos];
+    const ch = this.stream[this.pos];
     this.pos += 1;
     return ch;
   }
 
-  ch = this.stream[this.pos] & ((1 << this.remain) - 1);
+  let ch = this.stream[this.pos] & ((1 << this.remain) - 1);
   ch <<= 8 - this.remain;
 
   this.pos += 1;
@@ -473,11 +471,11 @@ BitReader.prototype.readByte = function readByte() {
 };
 
 BitReader.prototype.readBits = function readBits(count) {
-  let num = 0;
-
   assert(count >= 0);
   assert(count <= 32);
 
+  let num = 0;
+
   while (count >= 8) {
     num <<= 8;
     num |= this.readByte();
@@ -494,11 +492,11 @@ BitReader.prototype.readBits = function readBits(count) {
 };
 
 BitReader.prototype.readBits64 = function readBits(count) {
-  const num = new Int64();
-
   assert(count >= 0);
   assert(count <= 64);
 
+  const num = new Int64();
+
   if (count > 32) {
     num.hi = this.readBits(count - 32);
     num.lo = this.readBits(32);
diff --git a/lib/utils/heap.js b/lib/utils/heap.js
index a09e9f3e..17eef4cd 100644
--- a/lib/utils/heap.js
+++ b/lib/utils/heap.js
@@ -80,7 +80,7 @@ Heap.prototype.insert = function insert(item) {
 
 Heap.prototype.shift = function shift() {
   if (this.items.length === 0)
-    return;
+    return null;
 
   const n = this.items.length - 1;
 
@@ -98,12 +98,12 @@ Heap.prototype.shift = function shift() {
 
 Heap.prototype.remove = function remove(i) {
   if (this.items.length === 0)
-    return;
+    return null;
 
   const n = this.items.length - 1;
 
   if (i < 0 || i > n)
-    return;
+    return null;
 
   if (n !== i) {
     this.swap(i, n);
diff --git a/lib/utils/ip.js b/lib/utils/ip.js
index 50384343..18937391 100644
--- a/lib/utils/ip.js
+++ b/lib/utils/ip.js
@@ -269,10 +269,10 @@ IP.isMapped = function isMapped(raw) {
  */
 
 IP.toBuffer = function toBuffer(str) {
-  const raw = Buffer.allocUnsafe(16);
-
   assert(typeof str === 'string');
 
+  const raw = Buffer.allocUnsafe(16);
+
   if (IP.isV4String(str)) {
     raw.fill(0);
     raw[10] = 0xff;
@@ -329,8 +329,6 @@ IP.parseV4 = function parseV4(str, raw, offset) {
 IP.parseV6 = function parseV6(str, raw, offset) {
   const parts = str.split(':');
   let missing = 8 - parts.length;
-  const start = offset;
-  let colon = false;
 
   assert(parts.length >= 2, 'Not an IPv6 address.');
 
@@ -339,6 +337,9 @@ IP.parseV6 = function parseV6(str, raw, offset) {
       missing--;
   }
 
+  const start = offset;
+  let colon = false;
+
   for (let i = 0; i < parts.length; i++) {
     let word = parts[i];
 
@@ -855,13 +856,13 @@ IP.getReachability = function getReachability(src, dest) {
   const IPV6_STRONG = 5;
   const PRIVATE = 6;
 
+  if (!IP.isRoutable(src))
+    return UNREACHABLE;
+
   const srcNet = IP.getNetwork(src);
   const destNet = IP.getNetwork(dest);
   const types = IP.types;
 
-  if (!IP.isRoutable(src))
-    return UNREACHABLE;
-
   switch (destNet) {
     case types.IPV4:
       switch (srcNet) {
@@ -958,16 +959,7 @@ IP.hasPrefix = function hasPrefix(raw, prefix) {
 IP.isEqual = function isEqual(a, b) {
   assert(a.length === 16);
   assert(b.length === 16);
-
-  if (a.compare)
-    return a.compare(b) === 0;
-
-  for (let i = 0; i < a.length; i++) {
-    if (a[i] !== b[i])
-      return false;
-  }
-
-  return true;
+  return a.equals(b);
 };
 
 /**
@@ -994,7 +986,6 @@ IP.getInterfaces = function _getInterfaces(name, family) {
         continue;
 
       let raw;
-
       try {
         raw = IP.toBuffer(details.address);
       } catch (e) {
diff --git a/lib/utils/list.js b/lib/utils/list.js
index 03815eef..75844e17 100644
--- a/lib/utils/list.js
+++ b/lib/utils/list.js
@@ -55,7 +55,7 @@ List.prototype.shift = function shift() {
   const item = this.head;
 
   if (!item)
-    return;
+    return null;
 
   this.remove(item);
 
@@ -91,7 +91,7 @@ List.prototype.pop = function pop() {
   const item = this.tail;
 
   if (!item)
-    return;
+    return null;
 
   this.remove(item);
 
diff --git a/lib/utils/lock.js b/lib/utils/lock.js
index 3e341cb1..8b0e7fa7 100644
--- a/lib/utils/lock.js
+++ b/lib/utils/lock.js
@@ -174,10 +174,10 @@ Lock.prototype.destroy = function destroy() {
 
   this.destroyed = true;
 
-  const jobs = this.jobs.slice();
+  const jobs = this.jobs;
 
   this.busy = false;
-  this.jobs.length = 0;
+  this.jobs = [];
   this.map.clear();
   this.current = null;
 
diff --git a/lib/utils/lru.js b/lib/utils/lru.js
index 43f5dd51..4c0b2ef0 100644
--- a/lib/utils/lru.js
+++ b/lib/utils/lru.js
@@ -62,7 +62,6 @@ LRU.prototype._compact = function _compact() {
     return;
 
   let item, next;
-
   for (item = this.head; item; item = next) {
     if (this.size <= this.capacity)
       break;
@@ -150,14 +149,14 @@ LRU.prototype.set = function set(key, value) {
 
 LRU.prototype.get = function get(key) {
   if (this.capacity === 0)
-    return;
+    return null;
 
   key = key + '';
 
   const item = this.map.get(key);
 
   if (!item)
-    return;
+    return null;
 
   this._removeList(item);
   this._appendList(item);
@@ -185,7 +184,7 @@ LRU.prototype.has = function get(key) {
 
 LRU.prototype.remove = function remove(key) {
   if (this.capacity === 0)
-    return;
+    return false;
 
   key = key + '';
 
diff --git a/lib/utils/mappedlock.js b/lib/utils/mappedlock.js
index b15fd63e..a9d7fe97 100644
--- a/lib/utils/mappedlock.js
+++ b/lib/utils/mappedlock.js
@@ -132,10 +132,10 @@ MappedLock.prototype.unlock = function unlock(key) {
  */
 
 MappedLock.prototype.destroy = function destroy() {
-  const map = this.jobs;
-
   assert(!this.destroyed, 'Lock is already destroyed.');
 
+  const map = this.jobs;
+
   this.destroyed = true;
 
   this.jobs = new Map();
diff --git a/lib/utils/murmur3.js b/lib/utils/murmur3.js
index 0bb4c56c..57bda5db 100644
--- a/lib/utils/murmur3.js
+++ b/lib/utils/murmur3.js
@@ -72,14 +72,14 @@ function mul32(a, b) {
   const blo = b & 0xffff;
   const ahi = a >>> 16;
   const bhi = b >>> 16;
-  let r, lo, hi;
 
-  lo = alo * blo;
-  hi = (ahi * blo + bhi * alo) & 0xffff;
+  let lo = alo * blo;
+  let hi = (ahi * blo + bhi * alo) & 0xffff;
 
   hi += lo >>> 16;
   lo &= 0xffff;
-  r = (hi << 16) | lo;
+
+  let r = (hi << 16) | lo;
 
   if (r < 0)
     r += 0x100000000;
diff --git a/lib/utils/pem.js b/lib/utils/pem.js
index 12338f58..72218529 100644
--- a/lib/utils/pem.js
+++ b/lib/utils/pem.js
@@ -22,41 +22,56 @@ const PEM = exports;
  */
 
 PEM.parse = function parse(pem) {
-  let buf = '';
   const chunks = [];
-  let s, tag, type;
+  let chunk = '';
+  let tag;
 
   while (pem.length) {
-    if (s = /^-----BEGIN ([^\-]+)-----/.exec(pem)) {
-      pem = pem.substring(s[0].length);
-      tag = s[1];
+    let m;
+
+    if (m = /^-----BEGIN ([^\-]+)-----/.exec(pem)) {
+      pem = pem.substring(m[0].length);
+      tag = m[1];
       continue;
     }
-    if (s = /^-----END ([^\-]+)-----/.exec(pem)) {
-      pem = pem.substring(s[0].length);
-      assert(tag === s[1], 'Tag mismatch.');
-      buf = Buffer.from(buf, 'base64');
-      type = tag.split(' ')[0].toLowerCase();
-      chunks.push({ tag: tag, type: type, data: buf });
-      buf = '';
+
+    if (m = /^-----END ([^\-]+)-----/.exec(pem)) {
+      pem = pem.substring(m[0].length);
+
+      assert(tag === m[1], 'Tag mismatch.');
+
+      const type = tag.split(' ')[0].toLowerCase();
+      const data = Buffer.from(chunk, 'base64');
+
+      chunks.push({
+        tag: tag,
+        type: type,
+        data: data
+      });
+
+      chunk = '';
       tag = null;
+
       continue;
     }
-    if (s = /^[a-zA-Z0-9\+=\/]+/.exec(pem)) {
-      pem = pem.substring(s[0].length);
-      buf += s[0];
+
+    if (m = /^[a-zA-Z0-9\+=\/]+/.exec(pem)) {
+      pem = pem.substring(m[0].length);
+      chunk += m[0];
       continue;
     }
-    if (s = /^\s+/.exec(pem)) {
-      pem = pem.substring(s[0].length);
+
+    if (m = /^\s+/.exec(pem)) {
+      pem = pem.substring(m[0].length);
       continue;
     }
+
     throw new Error('PEM parse error.');
   }
 
   assert(chunks.length !== 0, 'PEM parse error.');
   assert(!tag, 'Un-ended tag.');
-  assert(buf.length === 0, 'Trailing data.');
+  assert(chunk.length === 0, 'Trailing data.');
 
   return chunks;
 };
@@ -72,13 +87,16 @@ PEM.decode = function decode(pem) {
   const chunks = PEM.parse(pem);
   const body = chunks[0];
   const extra = chunks[1];
-  let params, alg;
+
+  let params = null;
 
   if (extra) {
     if (extra.tag.indexOf('PARAMETERS') !== -1)
       params = extra.data;
   }
 
+  let alg = null;
+
   switch (body.type) {
     case 'dsa':
       alg = 'dsa';
@@ -121,6 +139,6 @@ PEM.encode = function encode(der, type, suffix) {
 
   return ''
     + `-----BEGIN ${type}-----\n`
-    + `${pem}`
+    + pem
     + `-----END ${type}-----\n`;
 };
diff --git a/lib/utils/protoreader.js b/lib/utils/protoreader.js
index 6dd66bf2..8a34f128 100644
--- a/lib/utils/protoreader.js
+++ b/lib/utils/protoreader.js
@@ -46,41 +46,56 @@ ProtoReader.prototype.readVarint = function _readVarint() {
 
 ProtoReader.prototype.readFieldValue = function readFieldValue(tag, opt) {
   const field = this.readField(tag, opt);
+
   if (!field)
     return -1;
+
   assert(field.value != null);
+
   return field.value;
 };
 
 ProtoReader.prototype.readFieldU64 = function readFieldU64(tag, opt) {
   const field = this.readField(tag, opt);
+
   if (!field)
     return -1;
+
   assert(field.type === wireType.VARINT || field.type === wireType.FIXED64);
+
   return field.value;
 };
 
 ProtoReader.prototype.readFieldU32 = function readFieldU32(tag, opt) {
   const field = this.readField(tag, opt);
+
   if (!field)
     return -1;
+
   assert(field.type === wireType.VARINT || field.type === wireType.FIXED32);
+
   return field.value;
 };
 
 ProtoReader.prototype.readFieldBytes = function readFieldBytes(tag, opt) {
   const field = this.readField(tag, opt);
+
   if (!field)
     return null;
+
   assert(field.data);
+
   return field.data;
 };
 
 ProtoReader.prototype.readFieldString = function readFieldString(tag, opt, enc) {
   const field = this.readField(tag, opt);
+
   if (!field)
     return null;
+
   assert(field.data);
+
   return field.data.toString(enc || 'utf8');
 };
 
diff --git a/lib/utils/protowriter.js b/lib/utils/protowriter.js
index 974b983d..b7894921 100644
--- a/lib/utils/protowriter.js
+++ b/lib/utils/protowriter.js
@@ -44,44 +44,50 @@ util.inherits(ProtoWriter, BufferWriter);
 
 ProtoWriter.prototype.writeVarint = function _writeVarint(num) {
   const size = sizeVarint(num);
-  let value;
 
   // Avoid an extra allocation until
   // we make bufferwriter more hackable.
   // More insanity here...
   switch (size) {
-    case 6:
-      value = slipVarint(num);
+    case 6: {
+      const value = slipVarint(num);
       this.writeU32BE(value / 0x10000 | 0);
       this.writeU16BE(value & 0xffff);
       break;
-    case 5:
-      value = slipVarint(num);
+    }
+    case 5: {
+      const value = slipVarint(num);
       this.writeU32BE(value / 0x100 | 0);
       this.writeU8(value & 0xff);
       break;
-    case 4:
-      value = slipVarint(num);
+    }
+    case 4: {
+      const value = slipVarint(num);
       this.writeU32BE(value);
       break;
-    case 3:
-      value = slipVarint(num);
+    }
+    case 3: {
+      const value = slipVarint(num);
       this.writeU16BE(value >> 8);
       this.writeU8(value & 0xff);
       break;
-    case 2:
-      value = slipVarint(num);
+    }
+    case 2: {
+      const value = slipVarint(num);
       this.writeU16BE(value);
       break;
-    case 1:
-      value = slipVarint(num);
+    }
+    case 1: {
+      const value = slipVarint(num);
       this.writeU8(value);
       break;
-    default:
-      value = Buffer.allocUnsafe(size);
+    }
+    default: {
+      const value = Buffer.allocUnsafe(size);
       writeVarint(value, num, 0);
       this.writeBytes(value);
       break;
+    }
   }
 };
 
@@ -119,13 +125,11 @@ ProtoWriter.prototype.writeFieldString = function writeFieldString(tag, data, en
  */
 
 function writeVarint(data, num, off) {
-  let ch;
-
   assert(util.isSafeInteger(num), 'Number exceeds 2^53-1.');
 
   do {
     assert(off < data.length);
-    ch = num & 0x7f;
+    let ch = num & 0x7f;
     num -= num % 0x80;
     num /= 0x80;
     if (num !== 0)
@@ -138,15 +142,14 @@ function writeVarint(data, num, off) {
 };
 
 function slipVarint(num) {
+  assert(util.isSafeInteger(num), 'Number exceeds 2^53-1.');
+
   let data = 0;
   let size = 0;
-  let ch;
-
-  assert(util.isSafeInteger(num), 'Number exceeds 2^53-1.');
 
   do {
     assert(size < 7);
-    ch = num & 0x7f;
+    let ch = num & 0x7f;
     num -= num % 0x80;
     num /= 0x80;
     if (num !== 0)
@@ -160,10 +163,10 @@ function slipVarint(num) {
 }
 
 function sizeVarint(num) {
-  let size = 0;
-
   assert(util.isSafeInteger(num), 'Number exceeds 2^53-1.');
 
+  let size = 0;
+
   do {
     num -= num % 0x80;
     num /= 0x80;
diff --git a/lib/utils/rbt.js b/lib/utils/rbt.js
index 6b16cd39..17454395 100644
--- a/lib/utils/rbt.js
+++ b/lib/utils/rbt.js
@@ -58,6 +58,8 @@ RBT.prototype.search = function search(key) {
     else
       current = current.right;
   }
+
+  return null;
 };
 
 /**
@@ -118,13 +120,11 @@ RBT.prototype.insert = function insert(key, value) {
  */
 
 RBT.prototype.insertFixup = function insertFixup(x) {
-  let y;
-
   x.color = RED;
 
   while (x !== this.root && x.parent.color === RED) {
     if (x.parent === x.parent.parent.left) {
-      y = x.parent.parent.right;
+      const y = x.parent.parent.right;
       if (!y.isNull() && y.color === RED) {
         x.parent.color = BLACK;
         y.color = BLACK;
@@ -140,7 +140,7 @@ RBT.prototype.insertFixup = function insertFixup(x) {
         this.rotr(x.parent.parent);
       }
     } else {
-      y = x.parent.parent.left;
+      const y = x.parent.parent.left;
       if (!y.isNull() && y.color === RED) {
         x.parent.color = BLACK;
         y.color = BLACK;
@@ -183,6 +183,8 @@ RBT.prototype.remove = function remove(key) {
     else
       current = current.right;
   }
+
+  return null;
 };
 
 /**
@@ -225,11 +227,9 @@ RBT.prototype.removeNode = function removeNode(z) {
  */
 
 RBT.prototype.removeFixup = function removeFixup(x) {
-  let w;
-
   while (x !== this.root && x.color === BLACK) {
     if (x === x.parent.left) {
-      w = x.parent.right;
+      let w = x.parent.right;
 
       if (w.color === RED) {
         w.color = BLACK;
@@ -255,7 +255,7 @@ RBT.prototype.removeFixup = function removeFixup(x) {
         x = this.root;
       }
     } else {
-      w = x.parent.left;
+      let w = x.parent.left;
 
       if (w.color === RED) {
         w.color = BLACK;
@@ -294,6 +294,7 @@ RBT.prototype.removeFixup = function removeFixup(x) {
 
 RBT.prototype.rotl = function rotl(x) {
   const y = x.right;
+
   x.right = y.left;
 
   if (!y.left.isNull())
@@ -322,6 +323,7 @@ RBT.prototype.rotl = function rotl(x) {
 
 RBT.prototype.rotr = function rotr(x) {
   const y = x.left;
+
   x.left = y.right;
 
   if (!y.right.isNull())
@@ -352,8 +354,10 @@ RBT.prototype.rotr = function rotr(x) {
 RBT.prototype.min = function min(z) {
   if (z.isNull())
     return z;
+
   while (!z.left.isNull())
     z = z.left;
+
   return z;
 };
 
@@ -367,8 +371,10 @@ RBT.prototype.min = function min(z) {
 RBT.prototype.max = function max(z) {
   if (z.isNull())
     return z;
+
   while (!z.right.isNull())
     z = z.right;
+
   return z;
 };
 
@@ -380,18 +386,21 @@ RBT.prototype.max = function max(z) {
  */
 
 RBT.prototype.successor = function successor(x) {
-  let y;
   if (!x.right.isNull()) {
     x = x.right;
+
     while (!x.left.isNull())
       x = x.left;
+
     return x;
   }
-  y = x.parent;
+
+  let y = x.parent;
   while (!y.isNull() && x === y.right) {
     x = y;
     y = y.parent;
   }
+
   return y;
 };
 
@@ -403,18 +412,21 @@ RBT.prototype.successor = function successor(x) {
  */
 
 RBT.prototype.predecessor = function predecessor(x) {
-  let y;
   if (!x.left.isNull()) {
     x = x.left;
+
     while (!x.right.isNull())
       x = x.right;
+
     return x;
   }
-  y = x.parent;
+
+  let y = x.parent;
   while (!y.isNull() && x === y.left) {
     x = y;
     y = y.parent;
   }
+
   return y;
 };
 
@@ -425,14 +437,18 @@ RBT.prototype.predecessor = function predecessor(x) {
  */
 
 RBT.prototype.clone = function clone() {
-  let current = this.root;
+  if (this.root.isNull())
+    return SENTINEL;
+
   const stack = [];
+
+  let current = this.root;
   let left = true;
-  let parent, copy, snapshot;
+  let parent, snapshot;
 
   for (;;) {
     if (!current.isNull()) {
-      copy = current.clone();
+      const copy = current.clone();
 
       if (parent)
         copy.parent = parent;
@@ -465,6 +481,8 @@ RBT.prototype.clone = function clone() {
     current = current.right;
   }
 
+  assert(snapshot);
+
   return snapshot;
 };
 
@@ -475,12 +493,10 @@ RBT.prototype.clone = function clone() {
  */
 
 RBT.prototype.snapshot = function snapshot() {
-  let node = SENTINEL;
-
   if (this.root.isNull())
-    return node;
+    return SENTINEL;
 
-  node = this.root.clone();
+  const node = this.root.clone();
 
   copyLeft(node, node.left);
   copyRight(node, node.right);
@@ -607,11 +623,11 @@ Iterator.prototype.seek = function seek(key) {
  */
 
 Iterator.prototype.seekMin = function seekMin(key) {
+  assert(key != null, 'No key passed to seek.');
+
   let root = this.current;
   let current = SENTINEL;
 
-  assert(key != null, 'No key passed to seek.');
-
   while (!root.isNull()) {
     const cmp = this.tree.compare(root.key, key);
 
@@ -639,11 +655,11 @@ Iterator.prototype.seekMin = function seekMin(key) {
  */
 
 Iterator.prototype.seekMax = function seekMax(key) {
+  assert(key != null, 'No key passed to seek.');
+
   let root = this.current;
   let current = SENTINEL;
 
-  assert(key != null, 'No key passed to seek.');
-
   while (!root.isNull()) {
     const cmp = this.tree.compare(root.key, key);
 
diff --git a/lib/utils/rollingfilter.js b/lib/utils/rollingfilter.js
index d79f545e..42b08b01 100644
--- a/lib/utils/rollingfilter.js
+++ b/lib/utils/rollingfilter.js
@@ -60,6 +60,7 @@ RollingFilter.prototype.fromRate = function fromRate(items, rate) {
   const limit = (items + 1) / 2 | 0;
 
   const max = limit * 3;
+
   let size = -1 * n * max / Math.log(1.0 - Math.exp(logRate / n));
   size = Math.ceil(size);
 
@@ -161,19 +162,16 @@ RollingFilter.prototype.add = function add(val, enc) {
     const hash = this.hash(val, i);
     const bits = hash & 0x3f;
     const pos = (hash >>> 6) % this.items;
-    let pos1 = (pos & ~1) * 8;
-    let pos2 = (pos | 1) * 8;
+    const pos1 = (pos & ~1) * 8;
+    const pos2 = (pos | 1) * 8;
     const bit = bits % 8;
     const oct = (bits - bit) / 8;
 
-    pos1 += oct;
-    pos2 += oct;
+    this.filter[pos1 + oct] &= ~(1 << bit);
+    this.filter[pos1 + oct] |= (this.generation & 1) << bit;
 
-    this.filter[pos1] &= ~(1 << bit);
-    this.filter[pos1] |= (this.generation & 1) << bit;
-
-    this.filter[pos2] &= ~(1 << bit);
-    this.filter[pos2] |= (this.generation >>> 1) << bit;
+    this.filter[pos2 + oct] &= ~(1 << bit);
+    this.filter[pos2 + oct] |= (this.generation >>> 1) << bit;
   }
 };
 
@@ -193,20 +191,17 @@ RollingFilter.prototype.test = function test(val, enc) {
 
   for (let i = 0; i < this.n; i++) {
     const hash = this.hash(val, i);
-    let bits = hash & 0x3f;
+    const bits = hash & 0x3f;
     const pos = (hash >>> 6) % this.items;
-    let pos1 = (pos & ~1) * 8;
-    let pos2 = (pos | 1) * 8;
+    const pos1 = (pos & ~1) * 8;
+    const pos2 = (pos | 1) * 8;
     const bit = bits % 8;
     const oct = (bits - bit) / 8;
 
-    pos1 += oct;
-    pos2 += oct;
+    const bit1 = (this.filter[pos1 + oct] >>> bit) & 1;
+    const bit2 = (this.filter[pos2 + oct] >>> bit) & 1;
 
-    bits = (this.filter[pos1] >>> bit) & 1;
-    bits |= (this.filter[pos2] >>> bit) & 1;
-
-    if (bits === 0)
+    if ((bit1 | bit2) === 0)
       return false;
   }
 
diff --git a/lib/utils/util.js b/lib/utils/util.js
index ef725bff..11c45c67 100644
--- a/lib/utils/util.js
+++ b/lib/utils/util.js
@@ -38,12 +38,12 @@ const inspectOptions = {
 
 util.hrtime = function hrtime(time) {
   if (!process.hrtime) {
-    let now = util.ms();
+    const now = util.ms();
 
     if (time) {
-      time = time[0] * 1000 + time[1] / 1e6;
-      now -= time;
-      return now;
+      const [hi, lo] = time;
+      const start = hi * 1000 + lo / 1e6;
+      return now - start;
     }
 
     const ms = now % 1000;
@@ -53,8 +53,8 @@ util.hrtime = function hrtime(time) {
   }
 
   if (time) {
-    const elapsed = process.hrtime(time);
-    return elapsed[0] * 1000 + elapsed[1] / 1e6;
+    const [hi, lo] = process.hrtime(time);
+    return hi * 1000 + lo / 1e6;
   }
 
   return process.hrtime();
@@ -519,7 +519,9 @@ util.indexOf = function indexOf(items, data) {
 
   for (let i = 0; i < items.length; i++) {
     const item = items[i];
+
     assert(Buffer.isBuffer(item));
+
     if (item.equals(data))
       return i;
   }
@@ -537,7 +539,9 @@ util.indexOf = function indexOf(items, data) {
 util.pad8 = function pad8(num) {
   assert(typeof num === 'number');
   assert(num >= 0);
+
   num = num + '';
+
   switch (num.length) {
     case 1:
       return '00' + num;
@@ -546,6 +550,7 @@ util.pad8 = function pad8(num) {
     case 3:
       return num;
   }
+
   assert(false);
 };
 
@@ -559,7 +564,9 @@ util.pad8 = function pad8(num) {
 util.pad32 = function pad32(num) {
   assert(typeof num === 'number');
   assert(num >= 0);
+
   num = num + '';
+
   switch (num.length) {
     case 1:
       return '000000000' + num;
@@ -581,9 +588,9 @@ util.pad32 = function pad32(num) {
       return '0' + num;
     case 10:
       return num;
-    default:
-      assert(false);
   }
+
+  assert(false);
 };
 
 /**
@@ -596,15 +603,17 @@ util.pad32 = function pad32(num) {
 util.hex8 = function hex8(num) {
   assert(typeof num === 'number');
   assert(num >= 0);
+
   num = num.toString(16);
+
   switch (num.length) {
     case 1:
       return '0' + num;
     case 2:
       return num;
-    default:
-      assert(false);
   }
+
+  assert(false);
 };
 
 /**
@@ -617,7 +626,9 @@ util.hex8 = function hex8(num) {
 util.hex32 = function hex32(num) {
   assert(typeof num === 'number');
   assert(num >= 0);
+
   num = num.toString(16);
+
   switch (num.length) {
     case 1:
       return '0000000' + num;
@@ -635,9 +646,9 @@ util.hex32 = function hex32(num) {
       return '0' + num;
     case 8:
       return num;
-    default:
-      assert(false);
   }
+
+  assert(false);
 };
 
 /**
diff --git a/lib/utils/validator.js b/lib/utils/validator.js
index caeee155..4407c249 100644
--- a/lib/utils/validator.js
+++ b/lib/utils/validator.js
@@ -439,8 +439,9 @@ Validator.prototype.bool = function bool(key, fallback) {
   if (value === null)
     return fallback;
 
-  // bitcoin core mixes semantics of truthiness amoung rpc methods
-  // most "verbose" parameters are bools, but getrawtransaction is 1/0
+  // Bitcoin Core mixes semantics of truthiness
+  // amoung rpc methods most "verbose" parameters
+  // are bools, but getrawtransaction is 1/0.
   if (value === 1)
     return true;
 
diff --git a/lib/wallet/account.js b/lib/wallet/account.js
index b43e4439..82b54fab 100644
--- a/lib/wallet/account.js
+++ b/lib/wallet/account.js
@@ -344,9 +344,8 @@ Account.prototype.spliceKey = function spliceKey(key) {
 
 Account.prototype.addSharedKey = async function addSharedKey(key) {
   const result = this.pushKey(key);
-  const exists = await this._hasDuplicate();
 
-  if (exists) {
+  if (await this.hasDuplicate()) {
     this.spliceKey(key);
     throw new Error('Cannot add a key from another account.');
   }
@@ -363,7 +362,7 @@ Account.prototype.addSharedKey = async function addSharedKey(key) {
  * @returns {Promise}
  */
 
-Account.prototype._hasDuplicate = function _hasDuplicate() {
+Account.prototype.hasDuplicate = function hasDuplicate() {
   if (this.keys.length !== this.n - 1)
     return false;
 
@@ -511,15 +510,13 @@ Account.prototype.derivePath = function derivePath(path, master) {
       if (path.encrypted) {
         data = master.decipher(data, path.hash);
         if (!data)
-          return;
+          return null;
       }
 
-      const ring = WalletKey.fromImport(this, data);
-
-      return ring;
+      return WalletKey.fromImport(this, data);
     }
     case Path.types.ADDRESS: {
-      return;
+      return null;
     }
     default: {
       assert(false, 'Bad key type.');
@@ -538,8 +535,8 @@ Account.prototype.deriveKey = function deriveKey(branch, index, master) {
   assert(typeof branch === 'number');
 
   const keys = [];
-  let key;
 
+  let key;
   if (master && master.key && !this.watchOnly) {
     key = master.key.deriveBIP44(this.accountIndex);
     key = key.derive(branch).derive(index);
@@ -555,9 +552,9 @@ Account.prototype.deriveKey = function deriveKey(branch, index, master) {
     case Account.types.MULTISIG:
       keys.push(key.publicKey);
 
-      for (let shared of this.keys) {
-        shared = shared.derive(branch).derive(index);
-        keys.push(shared.publicKey);
+      for (const shared of this.keys) {
+        const key = shared.derive(branch).derive(index);
+        keys.push(key.publicKey);
       }
 
       ring.script = Script.fromMultisig(this.m, this.n, keys);
@@ -800,7 +797,7 @@ Account.prototype.getAddress = function getAddress(enc) {
 
 Account.prototype.getReceive = function getReceive(enc) {
   if (!this.receive)
-    return;
+    return null;
   return this.receive.getAddress(enc);
 };
 
@@ -812,7 +809,8 @@ Account.prototype.getReceive = function getReceive(enc) {
 
 Account.prototype.getChange = function getChange(enc) {
   if (!this.change)
-    return;
+    return null;
+
   return this.change.getAddress(enc);
 };
 
@@ -824,7 +822,8 @@ Account.prototype.getChange = function getChange(enc) {
 
 Account.prototype.getNested = function getNested(enc) {
   if (!this.nested)
-    return;
+    return null;
+
   return this.nested.getAddress(enc);
 };
 
@@ -1004,8 +1003,8 @@ Account.isAccount = function isAccount(obj) {
  * Helpers
  */
 
-function cmp(key1, key2) {
-  return key1.compare(key2);
+function cmp(a, b) {
+  return a.compare(b);
 }
 
 /*
diff --git a/lib/wallet/common.js b/lib/wallet/common.js
index 8527bd9b..5f45ed65 100644
--- a/lib/wallet/common.js
+++ b/lib/wallet/common.js
@@ -82,21 +82,21 @@ common.sortCoins = function sortCoins(coins) {
 
 common.sortDeps = function sortDeps(txs) {
   const map = new Map();
-  const depMap = new Map();
-  const depCount = new Map();
-  const result = [];
-  const top = [];
 
   for (const tx of txs) {
     const hash = tx.hash('hex');
     map.set(hash, tx);
   }
 
-  for (const [hash, tx] of map) {
-    let hasDeps = false;
+  const depMap = new Map();
+  const depCount = new Map();
+  const top = [];
 
+  for (const [hash, tx] of map) {
     depCount.set(hash, 0);
 
+    let hasDeps = false;
+
     for (const input of tx.inputs) {
       const prev = input.prevout.hash;
 
@@ -119,6 +119,8 @@ common.sortDeps = function sortDeps(txs) {
     top.push(tx);
   }
 
+  const result = [];
+
   for (const tx of top) {
     const hash = tx.hash('hex');
     const deps = depMap.get(hash);
diff --git a/lib/wallet/http.js b/lib/wallet/http.js
index 91a282ce..8cd70419 100644
--- a/lib/wallet/http.js
+++ b/lib/wallet/http.js
@@ -134,8 +134,7 @@ HTTPServer.prototype.initRouter = function initRouter() {
       return;
     }
 
-    let wallet = null;
-
+    let wallet;
     try {
       wallet = await this.walletdb.auth(id, token);
     } catch (err) {
@@ -315,8 +314,11 @@ HTTPServer.prototype.initRouter = function initRouter() {
     const valid = req.valid();
     const old = valid.str('old');
     const new_ = valid.str('new');
+
     enforce(old || new_, 'Passphrase is required.');
+
     await req.wallet.setPassphrase(old, new_);
+
     res.send(200, { success: true });
   });
 
@@ -325,8 +327,11 @@ HTTPServer.prototype.initRouter = function initRouter() {
     const valid = req.valid();
     const passphrase = valid.str('passphrase');
     const timeout = valid.u32('timeout');
+
     enforce(passphrase, 'Passphrase is required.');
+
     await req.wallet.unlock(passphrase, timeout);
+
     res.send(200, { success: true });
   });
 
@@ -392,11 +397,11 @@ HTTPServer.prototype.initRouter = function initRouter() {
 
     for (const output of outputs) {
       const valid = new Validator([output]);
-      let script = null;
 
+      let script;
       if (valid.has('script')) {
-        script = valid.buf('script');
-        script = Script.fromRaw(script);
+        const raw = valid.buf('script');
+        script = Script.fromRaw(raw);
       }
 
       options.outputs.push({
@@ -431,11 +436,11 @@ HTTPServer.prototype.initRouter = function initRouter() {
 
     for (const output of outputs) {
       const valid = new Validator([output]);
-      let script = null;
 
+      let script;
       if (valid.has('script')) {
-        script = valid.buf('script');
-        script = Script.fromRaw(script);
+        const raw = valid.buf('script');
+        script = Script.fromRaw(raw);
       }
 
       options.outputs.push({
@@ -448,6 +453,7 @@ HTTPServer.prototype.initRouter = function initRouter() {
     const tx = await req.wallet.createTX(options);
 
     await req.wallet.sign(tx, passphrase);
+
     res.send(200, tx.getJSON(this.network));
   });
 
@@ -471,8 +477,11 @@ HTTPServer.prototype.initRouter = function initRouter() {
     const valid = req.valid();
     const acct = valid.str('account');
     const age = valid.u32('age');
+
     enforce(age, 'Age is required.');
+
     await req.wallet.zap(acct, age);
+
     res.send(200, { success: true });
   });
 
@@ -480,8 +489,11 @@ HTTPServer.prototype.initRouter = function initRouter() {
   this.del('/:id/tx/:hash', async (req, res) => {
     const valid = req.valid();
     const hash = valid.hash('hash');
+
     enforce(hash, 'Hash is required.');
+
     await req.wallet.abandon(hash);
+
     res.send(200, { success: true });
   });
 
@@ -513,8 +525,11 @@ HTTPServer.prototype.initRouter = function initRouter() {
     const valid = req.valid();
     const acct = valid.str('account');
     const key = valid.str('accountKey');
+
     enforce(key, 'Key is required.');
+
     await req.wallet.addSharedKey(acct, key);
+
     res.send(200, { success: true });
   });
 
@@ -523,8 +538,11 @@ HTTPServer.prototype.initRouter = function initRouter() {
     const valid = req.valid();
     const acct = valid.str('account');
     const key = valid.str('accountKey');
+
     enforce(key, 'Key is required.');
+
     await req.wallet.removeSharedKey(acct, key);
+
     res.send(200, { success: true });
   });
 
@@ -568,6 +586,7 @@ HTTPServer.prototype.initRouter = function initRouter() {
     const valid = req.valid();
     const acct = valid.str('account');
     const address = await req.wallet.createReceive(acct);
+
     res.send(200, address.toJSON());
   });
 
@@ -576,6 +595,7 @@ HTTPServer.prototype.initRouter = function initRouter() {
     const valid = req.valid();
     const acct = valid.str('account');
     const address = await req.wallet.createChange(acct);
+
     res.send(200, address.toJSON());
   });
 
@@ -584,6 +604,7 @@ HTTPServer.prototype.initRouter = function initRouter() {
     const valid = req.valid();
     const acct = valid.str('account');
     const address = await req.wallet.createNested(acct);
+
     res.send(200, address.toJSON());
   });
 
@@ -787,48 +808,36 @@ HTTPServer.prototype.initSockets = function initSockets() {
 
   this.walletdb.on('tx', (id, tx, details) => {
     const json = details.toJSON();
-    const channel = 'w:' + id;
-    this.to(channel, 'wallet tx', json);
-    this.to('!all', 'wallet tx', id, json);
+    this.to(`w:${id}`, 'wallet tx', json);
   });
 
   this.walletdb.on('confirmed', (id, tx, details) => {
     const json = details.toJSON();
-    const channel = 'w:' + id;
-    this.to(channel, 'wallet confirmed', json);
-    this.to('!all', 'wallet confirmed', id, json);
+    this.to(`w:${id}`, 'wallet confirmed', json);
   });
 
   this.walletdb.on('unconfirmed', (id, tx, details) => {
     const json = details.toJSON();
-    const channel = 'w:' + id;
-    this.to(channel, 'wallet unconfirmed', json);
-    this.to('!all', 'wallet unconfirmed', id, json);
+    this.to(`w:${id}`, 'wallet unconfirmed', json);
   });
 
   this.walletdb.on('conflict', (id, tx, details) => {
     const json = details.toJSON();
-    const channel = 'w:' + id;
-    this.to(channel, 'wallet conflict', json);
-    this.to('!all', 'wallet conflict', id, json);
+    this.to(`w:${id}`, 'wallet conflict', json);
   });
 
   this.walletdb.on('balance', (id, balance) => {
     const json = balance.toJSON();
-    const channel = 'w:' + id;
-    this.to(channel, 'wallet balance', json);
-    this.to('!all', 'wallet balance', id, json);
+    this.to(`w:${id}`, 'wallet balance', json);
   });
 
   this.walletdb.on('address', (id, receive) => {
-    const channel = 'w:' + id;
     const json = [];
 
     for (const addr of receive)
       json.push(addr.toJSON());
 
-    this.to(channel, 'wallet address', json);
-    this.to('!all', 'wallet address', id, json);
+    this.to(`w:${id}`, 'wallet address', json);
   });
 };
 
@@ -840,16 +849,21 @@ HTTPServer.prototype.initSockets = function initSockets() {
 
 HTTPServer.prototype.handleSocket = function handleSocket(socket) {
   socket.hook('wallet auth', (args) => {
-    const valid = new Validator([args]);
-    const key = valid.str(0);
-
     if (socket.auth)
       throw new Error('Already authed.');
 
     if (!this.options.noAuth) {
-      const hash = hash256(key);
+      const valid = new Validator([args]);
+      const key = valid.str(0);
+
+      if (key.length > 255)
+        throw new Error('Invalid API key.');
+
+      const data = Buffer.from(key, 'utf8');
+      const hash = digest.hash256(data);
+
       if (!ccmp(hash, this.options.apiHash))
-        throw new Error('Bad key.');
+        throw new Error('Invalid API key.');
     }
 
     socket.auth = true;
@@ -873,21 +887,19 @@ HTTPServer.prototype.handleAuth = function handleAuth(socket) {
     const valid = new Validator([args]);
     const id = valid.str(0, '');
     const token = valid.buf(1);
-    const channel = 'w:' + id;
 
     if (!id)
       throw new Error('Invalid parameter.');
 
     if (!this.options.walletAuth) {
-      socket.join(channel);
+      socket.join(`w:${id}`);
       return null;
     }
 
     if (!token)
       throw new Error('Invalid parameter.');
 
-    let wallet = null;
-
+    let wallet;
     try {
       wallet = await this.walletdb.auth(id, token);
     } catch (e) {
@@ -900,7 +912,7 @@ HTTPServer.prototype.handleAuth = function handleAuth(socket) {
 
     this.logger.info('Successful wallet auth for %s.', id);
 
-    socket.join(channel);
+    socket.join(`w:${id}`);
 
     return null;
   });
@@ -908,12 +920,11 @@ HTTPServer.prototype.handleAuth = function handleAuth(socket) {
   socket.hook('wallet leave', (args) => {
     const valid = new Validator([args]);
     const id = valid.str(0, '');
-    const channel = 'w:' + id;
 
     if (!id)
       throw new Error('Invalid parameter.');
 
-    socket.leave(channel);
+    socket.leave(`w:${id}`);
 
     return null;
   });
@@ -934,7 +945,7 @@ function HTTPOptions(options) {
   this.logger = null;
   this.walletdb = null;
   this.apiKey = base58.encode(random.randomBytes(20));
-  this.apiHash = hash256(this.apiKey);
+  this.apiHash = digest.hash256(Buffer.from(this.apiKey, 'utf8'));
   this.serviceHash = this.apiHash;
   this.noAuth = false;
   this.walletAuth = false;
@@ -977,7 +988,7 @@ HTTPOptions.prototype.fromOptions = function fromOptions(options) {
     assert(options.apiKey.length <= 200,
       'API key must be under 200 bytes.');
     this.apiKey = options.apiKey;
-    this.apiHash = hash256(this.apiKey);
+    this.apiHash = digest.hash256(Buffer.from(this.apiKey, 'utf8'));
   }
 
   if (options.noAuth != null) {
@@ -1047,16 +1058,6 @@ HTTPOptions.fromOptions = function fromOptions(options) {
  * Helpers
  */
 
-function hash256(data) {
-  if (typeof data !== 'string')
-    return Buffer.alloc(0);
-
-  if (data.length > 200)
-    return Buffer.alloc(0);
-
-  return digest.hash256(Buffer.from(data, 'utf8'));
-}
-
 function enforce(value, msg) {
   if (!value) {
     const err = new Error(msg);
diff --git a/lib/wallet/masterkey.js b/lib/wallet/masterkey.js
index fce5cfaf..e17d4a92 100644
--- a/lib/wallet/masterkey.js
+++ b/lib/wallet/masterkey.js
@@ -278,7 +278,7 @@ MasterKey.prototype.derive = async function derive(passwd) {
 
 MasterKey.prototype.encipher = function encipher(data, iv) {
   if (!this.aesKey)
-    return;
+    return null;
 
   if (typeof iv === 'string')
     iv = Buffer.from(iv, 'hex');
@@ -295,7 +295,7 @@ MasterKey.prototype.encipher = function encipher(data, iv) {
 
 MasterKey.prototype.decipher = function decipher(data, iv) {
   if (!this.aesKey)
-    return;
+    return null;
 
   if (typeof iv === 'string')
     iv = Buffer.from(iv, 'hex');
@@ -395,7 +395,7 @@ MasterKey.prototype._decrypt = async function decrypt(passphrase, clean) {
 
   if (!clean) {
     cleanse(key);
-    return;
+    return null;
   }
 
   return key;
@@ -446,7 +446,7 @@ MasterKey.prototype._encrypt = async function encrypt(passphrase, clean) {
 
   if (!clean) {
     cleanse(key);
-    return;
+    return null;
   }
 
   return key;
diff --git a/lib/wallet/nodeclient.js b/lib/wallet/nodeclient.js
index ec32d94d..08063c67 100644
--- a/lib/wallet/nodeclient.js
+++ b/lib/wallet/nodeclient.js
@@ -106,10 +106,10 @@ NodeClient.prototype.getEntry = async function getEntry(hash) {
   const entry = await this.node.chain.db.getEntry(hash);
 
   if (!entry)
-    return;
+    return null;
 
   if (!(await entry.isMainChain()))
-    return;
+    return null;
 
   return entry;
 };
@@ -164,10 +164,11 @@ NodeClient.prototype.resetFilter = function resetFilter() {
  * @returns {Promise}
  */
 
-NodeClient.prototype.estimateFee = function estimateFee(blocks) {
+NodeClient.prototype.estimateFee = async function estimateFee(blocks) {
   if (!this.node.fees)
-    return Promise.resolve(this.network.feeRate);
-  return Promise.resolve(this.node.fees.estimateFee(blocks));
+    return this.network.feeRate;
+
+  return this.node.fees.estimateFee(blocks);
 };
 
 /**
diff --git a/lib/wallet/records.js b/lib/wallet/records.js
index 94ca0dcd..2b78c808 100644
--- a/lib/wallet/records.js
+++ b/lib/wallet/records.js
@@ -321,7 +321,7 @@ BlockMapRecord.prototype.add = function add(hash, wid) {
 
   if (!tx) {
     tx = new TXMapRecord(hash);
-    this.txs.set(tx.hash, tx);
+    this.txs.set(hash, tx);
   }
 
   return tx.add(wid);
@@ -600,7 +600,8 @@ TXRecord.prototype.unsetBlock = function unsetBlock() {
 
 TXRecord.prototype.getBlock = function getBlock() {
   if (this.height === -1)
-    return;
+    return null;
+
   return new BlockMeta(this.block, this.height, this.time);
 };
 
diff --git a/lib/wallet/rpc.js b/lib/wallet/rpc.js
index a67255a4..2ece9778 100644
--- a/lib/wallet/rpc.js
+++ b/lib/wallet/rpc.js
@@ -132,16 +132,16 @@ RPC.prototype.stop = async function stop(args, help) {
 };
 
 RPC.prototype.fundRawTransaction = async function fundRawTransaction(args, help) {
-  const valid = new Validator([args]);
-  const data = valid.buf(0);
-  const options = valid.obj(1);
-  const wallet = this.wallet;
-
   if (help || args.length < 1 || args.length > 2) {
     throw new RPCError(errs.MISC_ERROR,
       'fundrawtransaction "hexstring" ( options )');
   }
 
+  const wallet = this.wallet;
+  const valid = new Validator([args]);
+  const data = valid.buf(0);
+  const options = valid.obj(1);
+
   if (!data)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid hex string.');
 
@@ -153,13 +153,15 @@ RPC.prototype.fundRawTransaction = async function fundRawTransaction(args, help)
   }
 
   let rate = this.feeRate;
-  let change = null;
-
+  let change;
   if (options) {
     const valid = new Validator([options]);
 
-    change = valid.str('changeAddress');
-    rate = valid.btc('feeRate');
+    if (valid.has('feeRate'))
+      rate = valid.btc('feeRate');
+
+    if (valid.has('changeAddress'))
+      change = valid.str('changeAddress');
 
     if (change)
       change = parseAddress(change, this.network);
@@ -182,13 +184,12 @@ RPC.prototype.fundRawTransaction = async function fundRawTransaction(args, help)
  */
 
 RPC.prototype.resendWalletTransactions = async function resendWalletTransactions(args, help) {
-  const wallet = this.wallet;
-  const hashes = [];
-
   if (help || args.length !== 0)
     throw new RPCError(errs.MISC_ERROR, 'resendwallettransactions');
 
+  const wallet = this.wallet;
   const txs = await wallet.resend();
+  const hashes = [];
 
   for (const tx of txs)
     hashes.push(tx.txid());
@@ -215,25 +216,25 @@ RPC.prototype.addWitnessAddress = async function addWitnessAddress(args, help) {
 };
 
 RPC.prototype.backupWallet = async function backupWallet(args, help) {
-  const valid = new Validator([args]);
-  const dest = valid.str(0);
-
   if (help || args.length !== 1 || !dest)
     throw new RPCError(errs.MISC_ERROR, 'backupwallet "destination"');
 
+  const valid = new Validator([args]);
+  const dest = valid.str(0);
+
   await this.wdb.backup(dest);
 
   return null;
 };
 
 RPC.prototype.dumpPrivKey = async function dumpPrivKey(args, help) {
+  if (help || args.length !== 1)
+    throw new RPCError(errs.MISC_ERROR, 'dumpprivkey "bitcoinaddress"');
+
   const wallet = this.wallet;
   const valid = new Validator([args]);
   const addr = valid.str(0, '');
 
-  if (help || args.length !== 1)
-    throw new RPCError(errs.MISC_ERROR, 'dumpprivkey "bitcoinaddress"');
-
   const hash = parseHash(addr, this.network);
   const ring = await wallet.getPrivateKey(hash);
 
@@ -244,18 +245,18 @@ RPC.prototype.dumpPrivKey = async function dumpPrivKey(args, help) {
 };
 
 RPC.prototype.dumpWallet = async function dumpWallet(args, help) {
+  if (help || args.length !== 1)
+    throw new RPCError(errs.MISC_ERROR, 'dumpwallet "filename"');
+
   const wallet = this.wallet;
   const valid = new Validator([args]);
   const file = valid.str(0);
-  const time = util.date();
-
-  if (help || args.length !== 1)
-    throw new RPCError(errs.MISC_ERROR, 'dumpwallet "filename"');
 
   if (!file)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid parameter.');
 
   const tip = await this.wdb.getTip();
+  const time = util.date();
 
   const out = [
     util.fmt('# Wallet Dump created by Bcoin %s', pkg.version),
@@ -302,12 +303,13 @@ RPC.prototype.dumpWallet = async function dumpWallet(args, help) {
 
 RPC.prototype.encryptWallet = async function encryptWallet(args, help) {
   const wallet = this.wallet;
-  const valid = new Validator([args]);
-  const passphrase = valid.str(0, '');
 
   if (!wallet.master.encrypted && (help || args.length !== 1))
     throw new RPCError(errs.MISC_ERROR, 'encryptwallet "passphrase"');
 
+  const valid = new Validator([args]);
+  const passphrase = valid.str(0, '');
+
   if (wallet.master.encrypted) {
     throw new RPCError(errs.WALLET_WRONG_ENC_STATE,
       'Already running with an encrypted wallet.');
@@ -326,13 +328,13 @@ RPC.prototype.encryptWallet = async function encryptWallet(args, help) {
 };
 
 RPC.prototype.getAccountAddress = async function getAccountAddress(args, help) {
-  const valid = new Validator([args]);
-  const wallet = this.wallet;
-  let name = valid.str(0, '');
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'getaccountaddress "account"');
 
+  const wallet = this.wallet;
+  const valid = new Validator([args]);
+  let name = valid.str(0, '');
+
   if (!name)
     name = 'default';
 
@@ -345,13 +347,13 @@ RPC.prototype.getAccountAddress = async function getAccountAddress(args, help) {
 };
 
 RPC.prototype.getAccount = async function getAccount(args, help) {
+  if (help || args.length !== 1)
+    throw new RPCError(errs.MISC_ERROR, 'getaccount "bitcoinaddress"');
+
   const wallet = this.wallet;
   const valid = new Validator([args]);
   const addr = valid.str(0, '');
 
-  if (help || args.length !== 1)
-    throw new RPCError(errs.MISC_ERROR, 'getaccount "bitcoinaddress"');
-
   const hash = parseHash(addr, this.network);
   const path = await wallet.getPath(hash);
 
@@ -362,14 +364,14 @@ RPC.prototype.getAccount = async function getAccount(args, help) {
 };
 
 RPC.prototype.getAddressesByAccount = async function getAddressesByAccount(args, help) {
+  if (help || args.length !== 1)
+    throw new RPCError(errs.MISC_ERROR, 'getaddressesbyaccount "account"');
+
   const wallet = this.wallet;
   const valid = new Validator([args]);
   let name = valid.str(0, '');
   const addrs = [];
 
-  if (help || args.length !== 1)
-    throw new RPCError(errs.MISC_ERROR, 'getaddressesbyaccount "account"');
-
   if (name === '')
     name = 'default';
 
@@ -384,17 +386,17 @@ RPC.prototype.getAddressesByAccount = async function getAddressesByAccount(args,
 };
 
 RPC.prototype.getBalance = async function getBalance(args, help) {
+  if (help || args.length > 3) {
+    throw new RPCError(errs.MISC_ERROR,
+      'getbalance ( "account" minconf includeWatchonly )');
+  }
+
   const wallet = this.wallet;
   const valid = new Validator([args]);
   let name = valid.str(0);
   const minconf = valid.u32(1, 0);
   const watchOnly = valid.bool(2, false);
 
-  if (help || args.length > 3) {
-    throw new RPCError(errs.MISC_ERROR,
-      'getbalance ( "account" minconf includeWatchonly )');
-  }
-
   if (name === '')
     name = 'default';
 
@@ -405,8 +407,8 @@ RPC.prototype.getBalance = async function getBalance(args, help) {
     return 0;
 
   const balance = await wallet.getBalance(name);
-  let value;
 
+  let value;
   if (minconf > 0)
     value = balance.confirmed;
   else
@@ -416,13 +418,13 @@ RPC.prototype.getBalance = async function getBalance(args, help) {
 };
 
 RPC.prototype.getNewAddress = async function getNewAddress(args, help) {
+  if (help || args.length > 1)
+    throw new RPCError(errs.MISC_ERROR, 'getnewaddress ( "account" )');
+
   const wallet = this.wallet;
   const valid = new Validator([args]);
   let name = valid.str(0);
 
-  if (help || args.length > 1)
-    throw new RPCError(errs.MISC_ERROR, 'getnewaddress ( "account" )');
-
   if (name === '')
     name = 'default';
 
@@ -432,41 +434,41 @@ RPC.prototype.getNewAddress = async function getNewAddress(args, help) {
 };
 
 RPC.prototype.getRawChangeAddress = async function getRawChangeAddress(args, help) {
-  const wallet = this.wallet;
-
   if (help || args.length > 1)
     throw new RPCError(errs.MISC_ERROR, 'getrawchangeaddress');
 
+  const wallet = this.wallet;
   const addr = await wallet.createChange();
 
   return addr.getAddress('string');
 };
 
 RPC.prototype.getReceivedByAccount = async function getReceivedByAccount(args, help) {
-  const wallet = this.wallet;
-  const valid = new Validator([args]);
-  let name = valid.str(0);
-  const minconf = valid.u32(0, 0);
-  const height = this.wdb.state.height;
-  const filter = new Set();
-  let total = 0;
-  let lastConf = -1;
-
   if (help || args.length < 1 || args.length > 2) {
     throw new RPCError(errs.MISC_ERROR,
       'getreceivedbyaccount "account" ( minconf )');
   }
 
+  const wallet = this.wallet;
+  const valid = new Validator([args]);
+  let name = valid.str(0);
+  const minconf = valid.u32(1, 0);
+  const height = this.wdb.state.height;
+
   if (name === '')
     name = 'default';
 
   const paths = await wallet.getPaths(name);
+  const filter = new Set();
 
   for (const path of paths)
     filter.add(path.hash);
 
   const txs = await wallet.getHistory(name);
 
+  let total = 0;
+  let lastConf = -1;
+
   for (const wtx of txs) {
     const conf = wtx.getDepth(height);
 
@@ -487,21 +489,22 @@ RPC.prototype.getReceivedByAccount = async function getReceivedByAccount(args, h
 };
 
 RPC.prototype.getReceivedByAddress = async function getReceivedByAddress(args, help) {
-  const wallet = this.wallet;
-  const valid = new Validator([args]);
-  const addr = valid.str(0, '');
-  const minconf = valid.u32(1, 0);
-  const height = this.wdb.state.height;
-  let total = 0;
-
   if (help || args.length < 1 || args.length > 2) {
     throw new RPCError(errs.MISC_ERROR,
       'getreceivedbyaddress "bitcoinaddress" ( minconf )');
   }
 
+  const wallet = this.wallet;
+  const valid = new Validator([args]);
+  const addr = valid.str(0, '');
+  const minconf = valid.u32(1, 0);
+  const height = this.wdb.state.height;
+
   const hash = parseHash(addr, this.network);
   const txs = await wallet.getHistory();
 
+  let total = 0;
+
   for (const wtx of txs) {
     if (wtx.getDepth(height) < minconf)
       continue;
@@ -518,14 +521,11 @@ RPC.prototype.getReceivedByAddress = async function getReceivedByAddress(args, h
 RPC.prototype._toWalletTX = async function _toWalletTX(wtx) {
   const wallet = this.wallet;
   const details = await wallet.toDetails(wtx);
-  const det = [];
-  let sent = 0;
-  let received = 0;
-  let receive = true;
 
   if (!details)
     throw new RPCError(errs.WALLET_ERROR, 'TX not found.');
 
+  let receive = true;
   for (const member of details.inputs) {
     if (member.path) {
       receive = false;
@@ -533,6 +533,10 @@ RPC.prototype._toWalletTX = async function _toWalletTX(wtx) {
     }
   }
 
+  const det = [];
+  let sent = 0;
+  let received = 0;
+
   for (let i = 0; i < details.outputs.length; i++) {
     const member = details.outputs[i];
 
@@ -588,16 +592,16 @@ RPC.prototype._toWalletTX = async function _toWalletTX(wtx) {
 };
 
 RPC.prototype.getTransaction = async function getTransaction(args, help) {
-  const wallet = this.wallet;
-  const valid = new Validator([args]);
-  const hash = valid.hash(0);
-  const watchOnly = valid.bool(1, false);
-
   if (help || args.length < 1 || args.length > 2) {
     throw new RPCError(errs.MISC_ERROR,
       'gettransaction "txid" ( includeWatchonly )');
   }
 
+  const wallet = this.wallet;
+  const valid = new Validator([args]);
+  const hash = valid.hash(0);
+  const watchOnly = valid.bool(1, false);
+
   if (!hash)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid parameter');
 
@@ -610,13 +614,13 @@ RPC.prototype.getTransaction = async function getTransaction(args, help) {
 };
 
 RPC.prototype.abandonTransaction = async function abandonTransaction(args, help) {
+  if (help || args.length !== 1)
+    throw new RPCError(errs.MISC_ERROR, 'abandontransaction "txid"');
+
   const wallet = this.wallet;
   const valid = new Validator([args]);
   const hash = valid.hash(0);
 
-  if (help || args.length !== 1)
-    throw new RPCError(errs.MISC_ERROR, 'abandontransaction "txid"');
-
   if (!hash)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid parameter.');
 
@@ -629,22 +633,20 @@ RPC.prototype.abandonTransaction = async function abandonTransaction(args, help)
 };
 
 RPC.prototype.getUnconfirmedBalance = async function getUnconfirmedBalance(args, help) {
-  const wallet = this.wallet;
-
   if (help || args.length > 0)
     throw new RPCError(errs.MISC_ERROR, 'getunconfirmedbalance');
 
+  const wallet = this.wallet;
   const balance = await wallet.getBalance();
 
   return Amount.btc(balance.unconfirmed, true);
 };
 
 RPC.prototype.getWalletInfo = async function getWalletInfo(args, help) {
-  const wallet = this.wallet;
-
   if (help || args.length !== 0)
     throw new RPCError(errs.MISC_ERROR, 'getwalletinfo');
 
+  const wallet = this.wallet;
   const balance = await wallet.getBalance();
 
   return {
@@ -663,16 +665,16 @@ RPC.prototype.getWalletInfo = async function getWalletInfo(args, help) {
 };
 
 RPC.prototype.importPrivKey = async function importPrivKey(args, help) {
-  const wallet = this.wallet;
-  const valid = new Validator([args]);
-  const secret = valid.str(0);
-  const rescan = valid.bool(2, false);
-
   if (help || args.length < 1 || args.length > 3) {
     throw new RPCError(errs.MISC_ERROR,
       'importprivkey "bitcoinprivkey" ( "label" rescan )');
   }
 
+  const wallet = this.wallet;
+  const valid = new Validator([args]);
+  const secret = valid.str(0);
+  const rescan = valid.bool(2, false);
+
   const key = parseSecret(secret, this.network);
 
   await wallet.importKey(0, key);
@@ -684,21 +686,20 @@ RPC.prototype.importPrivKey = async function importPrivKey(args, help) {
 };
 
 RPC.prototype.importWallet = async function importWallet(args, help) {
+  if (help || args.length !== 1)
+    throw new RPCError(errs.MISC_ERROR, 'importwallet "filename" ( rescan )');
+
   const wallet = this.wallet;
   const valid = new Validator([args]);
   const file = valid.str(0);
   const rescan = valid.bool(1, false);
-  const keys = [];
-
-  if (help || args.length !== 1)
-    throw new RPCError(errs.MISC_ERROR, 'importwallet "filename" ( rescan )');
 
   if (fs.unsupported)
     throw new RPCError(errs.INTERNAL_ERROR, 'FS not available.');
 
   const data = await fs.readFile(file, 'utf8');
-
   const lines = data.split(/\n+/);
+  const keys = [];
 
   for (let line of lines) {
     line = line.trim();
@@ -729,17 +730,17 @@ RPC.prototype.importWallet = async function importWallet(args, help) {
 };
 
 RPC.prototype.importAddress = async function importAddress(args, help) {
+  if (help || args.length < 1 || args.length > 4) {
+    throw new RPCError(errs.MISC_ERROR,
+      'importaddress "address" ( "label" rescan p2sh )');
+  }
+
   const wallet = this.wallet;
   const valid = new Validator([args]);
   let addr = valid.str(0, '');
   const rescan = valid.bool(2, false);
   const p2sh = valid.bool(3, false);
 
-  if (help || args.length < 1 || args.length > 4) {
-    throw new RPCError(errs.MISC_ERROR,
-      'importaddress "address" ( "label" rescan p2sh )');
-  }
-
   if (p2sh) {
     let script = valid.buf(0);
 
@@ -763,16 +764,16 @@ RPC.prototype.importAddress = async function importAddress(args, help) {
 };
 
 RPC.prototype.importPubkey = async function importPubkey(args, help) {
-  const wallet = this.wallet;
-  const valid = new Validator([args]);
-  const data = valid.buf(0);
-  const rescan = valid.bool(2, false);
-
   if (help || args.length < 1 || args.length > 4) {
     throw new RPCError(errs.MISC_ERROR,
       'importpubkey "pubkey" ( "label" rescan )');
   }
 
+  const wallet = this.wallet;
+  const valid = new Validator([args]);
+  const data = valid.buf(0);
+  const rescan = valid.bool(2, false);
+
   if (!data)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid parameter.');
 
@@ -793,18 +794,18 @@ RPC.prototype.keyPoolRefill = async function keyPoolRefill(args, help) {
 };
 
 RPC.prototype.listAccounts = async function listAccounts(args, help) {
-  const wallet = this.wallet;
-  const valid = new Validator([args]);
-  const minconf = valid.u32(0, 0);
-  const watchOnly = valid.bool(1, false);
-  const map = {};
-
   if (help || args.length > 2) {
     throw new RPCError(errs.MISC_ERROR,
       'listaccounts ( minconf includeWatchonly)');
   }
 
+  const wallet = this.wallet;
+  const valid = new Validator([args]);
+  const minconf = valid.u32(0, 0);
+  const watchOnly = valid.bool(1, false);
+
   const accounts = await wallet.getAccounts();
+  const map = {};
 
   for (const account of accounts) {
     const balance = await wallet.getBalance(account);
@@ -829,13 +830,12 @@ RPC.prototype.listAddressGroupings = async function listAddressGroupings(args, h
 };
 
 RPC.prototype.listLockUnspent = async function listLockUnspent(args, help) {
-  const wallet = this.wallet;
-  const out = [];
-
   if (help || args.length > 0)
     throw new RPCError(errs.MISC_ERROR, 'listlockunspent');
 
+  const wallet = this.wallet;
   const outpoints = wallet.getLocked();
+  const out = [];
 
   for (const outpoint of outpoints) {
     out.push({
@@ -848,30 +848,30 @@ RPC.prototype.listLockUnspent = async function listLockUnspent(args, help) {
 };
 
 RPC.prototype.listReceivedByAccount = async function listReceivedByAccount(args, help) {
-  const valid = new Validator([args]);
-  const minconf = valid.u32(0, 0);
-  const includeEmpty = valid.bool(1, false);
-  const watchOnly = valid.bool(2, false);
-
   if (help || args.length > 3) {
     throw new RPCError(errs.MISC_ERROR,
       'listreceivedbyaccount ( minconf includeempty includeWatchonly )');
   }
 
-  return await this._listReceived(minconf, includeEmpty, watchOnly, true);
-};
-
-RPC.prototype.listReceivedByAddress = async function listReceivedByAddress(args, help) {
   const valid = new Validator([args]);
   const minconf = valid.u32(0, 0);
   const includeEmpty = valid.bool(1, false);
   const watchOnly = valid.bool(2, false);
 
+  return await this._listReceived(minconf, includeEmpty, watchOnly, true);
+};
+
+RPC.prototype.listReceivedByAddress = async function listReceivedByAddress(args, help) {
   if (help || args.length > 3) {
     throw new RPCError(errs.MISC_ERROR,
       'listreceivedbyaddress ( minconf includeempty includeWatchonly )');
   }
 
+  const valid = new Validator([args]);
+  const minconf = valid.u32(0, 0);
+  const includeEmpty = valid.bool(1, false);
+  const watchOnly = valid.bool(2, false);
+
   return await this._listReceived(minconf, includeEmpty, watchOnly, false);
 };
 
@@ -879,10 +879,8 @@ RPC.prototype._listReceived = async function _listReceived(minconf, empty, watch
   const wallet = this.wallet;
   const paths = await wallet.getPaths();
   const height = this.wdb.state.height;
-  const map = new Map();
-  let out = [];
-  const result = [];
 
+  const map = new Map();
   for (const path of paths) {
     const addr = path.toAddress();
     map.set(path.hash, {
@@ -921,6 +919,7 @@ RPC.prototype._listReceived = async function _listReceived(minconf, empty, watch
     }
   }
 
+  let out = [];
   for (const entry of map.values())
     out.push(entry);
 
@@ -943,6 +942,7 @@ RPC.prototype._listReceived = async function _listReceived(minconf, empty, watch
       out.push(entry);
   }
 
+  const result = [];
   for (const entry of out) {
     if (!empty && entry.amount === 0)
       continue;
@@ -964,9 +964,6 @@ RPC.prototype.listSinceBlock = async function listSinceBlock(args, help) {
   const block = valid.hash(0);
   const minconf = valid.u32(1, 0);
   const watchOnly = valid.bool(2, false);
-  let height = -1;
-  const out = [];
-  let highest;
 
   if (help) {
     throw new RPCError(errs.MISC_ERROR,
@@ -974,8 +971,9 @@ RPC.prototype.listSinceBlock = async function listSinceBlock(args, help) {
   }
 
   if (wallet.watchOnly !== watchOnly)
-    return out;
+    return [];
 
+  let height = -1;
   if (block) {
     const entry = await this.client.getEntry(block);
     if (entry)
@@ -987,6 +985,8 @@ RPC.prototype.listSinceBlock = async function listSinceBlock(args, help) {
 
   const txs = await wallet.getHistory();
 
+  const out = [];
+  let highest;
   for (const wtx of txs) {
     if (wtx.height < height)
       continue;
@@ -1013,14 +1013,11 @@ RPC.prototype.listSinceBlock = async function listSinceBlock(args, help) {
 RPC.prototype._toListTX = async function _toListTX(wtx) {
   const wallet = this.wallet;
   const details = await wallet.toDetails(wtx);
-  let sent = 0;
-  let received = 0;
-  let receive = true;
-  let sendMember, recMember, sendIndex, recIndex;
 
   if (!details)
     throw new RPCError(errs.WALLET_ERROR, 'TX not found.');
 
+  let receive = true;
   for (const member of details.inputs) {
     if (member.path) {
       receive = false;
@@ -1028,6 +1025,9 @@ RPC.prototype._toListTX = async function _toListTX(wtx) {
     }
   }
 
+  let sent = 0;
+  let received = 0;
+  let sendMember, recMember, sendIndex, recIndex;
   for (let i = 0; i < details.outputs.length; i++) {
     const member = details.outputs[i];
 
@@ -1046,7 +1046,6 @@ RPC.prototype._toListTX = async function _toListTX(wtx) {
   }
 
   let member, index;
-
   if (receive) {
     member = recMember;
     index = recIndex;
@@ -1084,22 +1083,20 @@ RPC.prototype._toListTX = async function _toListTX(wtx) {
 };
 
 RPC.prototype.listTransactions = async function listTransactions(args, help) {
+  if (help || args.length > 4) {
+    throw new RPCError(errs.MISC_ERROR,
+      'listtransactions ( "account" count from includeWatchonly)');
+  }
+
   const wallet = this.wallet;
   const valid = new Validator([args]);
   let name = valid.str(0);
   const count = valid.u32(1, 10);
   const from = valid.u32(2, 0);
   const watchOnly = valid.bool(3, false);
-  let end = from + count;
-  const out = [];
-
-  if (help || args.length > 4) {
-    throw new RPCError(errs.MISC_ERROR,
-      'listtransactions ( "account" count from includeWatchonly)');
-  }
 
   if (wallet.watchOnly !== watchOnly)
-    return out;
+    return [];
 
   if (name === '')
     name = 'default';
@@ -1108,9 +1105,11 @@ RPC.prototype.listTransactions = async function listTransactions(args, help) {
 
   common.sortTX(txs);
 
-  end = Math.min(end, txs.length);
+  const end = from + count;
+  const to = Math.min(end, txs.length);
+  const out = [];
 
-  for (let i = from; i < end; i++) {
+  for (let i = from; i < to; i++) {
     const wtx = txs[i];
     const json = await this._toListTX(wtx);
     out.push(json);
@@ -1120,19 +1119,19 @@ RPC.prototype.listTransactions = async function listTransactions(args, help) {
 };
 
 RPC.prototype.listUnspent = async function listUnspent(args, help) {
+  if (help || args.length > 3) {
+    throw new RPCError(errs.MISC_ERROR,
+      'listunspent ( minconf maxconf  ["address",...] )');
+  }
+
   const wallet = this.wallet;
   const valid = new Validator([args]);
   const minDepth = valid.u32(0, 1);
   const maxDepth = valid.u32(1, 9999999);
   const addrs = valid.array(2);
   const height = this.wdb.state.height;
-  const map = new Set();
-  const out = [];
 
-  if (help || args.length > 3) {
-    throw new RPCError(errs.MISC_ERROR,
-      'listunspent ( minconf maxconf  ["address",...] )');
-  }
+  const map = new Set();
 
   if (addrs) {
     const valid = new Validator([addrs]);
@@ -1151,6 +1150,8 @@ RPC.prototype.listUnspent = async function listUnspent(args, help) {
 
   common.sortCoins(coins);
 
+  const out = [];
+
   for (const coin of coins) {
     const depth = coin.getDepth(height);
 
@@ -1191,16 +1192,16 @@ RPC.prototype.listUnspent = async function listUnspent(args, help) {
 };
 
 RPC.prototype.lockUnspent = async function lockUnspent(args, help) {
-  const wallet = this.wallet;
-  const valid = new Validator([args]);
-  const unlock = valid.bool(0, false);
-  const outputs = valid.array(1);
-
   if (help || args.length < 1 || args.length > 2) {
     throw new RPCError(errs.MISC_ERROR,
       'lockunspent unlock ([{"txid":"txid","vout":n},...])');
   }
 
+  const wallet = this.wallet;
+  const valid = new Validator([args]);
+  const unlock = valid.bool(0, false);
+  const outputs = valid.array(1);
+
   if (args.length === 1) {
     if (unlock)
       wallet.unlockCoins();
@@ -1218,9 +1219,7 @@ RPC.prototype.lockUnspent = async function lockUnspent(args, help) {
     if (hash == null || index == null)
       throw new RPCError(errs.INVALID_PARAMETER, 'Invalid parameter.');
 
-    const outpoint = new Outpoint();
-    outpoint.hash = hash;
-    outpoint.index = index;
+    const outpoint = new Outpoint(hash, index);
 
     if (unlock) {
       wallet.unlockCoin(outpoint);
@@ -1239,6 +1238,12 @@ RPC.prototype.move = async function move(args, help) {
 };
 
 RPC.prototype.sendFrom = async function sendFrom(args, help) {
+  if (help || args.length < 3 || args.length > 6) {
+    throw new RPCError(errs.MISC_ERROR,
+      'sendfrom "fromaccount" "tobitcoinaddress"'
+      + ' amount ( minconf "comment" "comment-to" )');
+  }
+
   const wallet = this.wallet;
   const valid = new Validator([args]);
   let name = valid.str(0);
@@ -1246,17 +1251,11 @@ RPC.prototype.sendFrom = async function sendFrom(args, help) {
   const value = valid.btc(2);
   const minconf = valid.u32(3, 0);
 
-  if (help || args.length < 3 || args.length > 6) {
-    throw new RPCError(errs.MISC_ERROR,
-      'sendfrom "fromaccount" "tobitcoinaddress"'
-      + ' amount ( minconf "comment" "comment-to" )');
-  }
+  const addr = parseAddress(str, this.network);
 
   if (!addr || value == null)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid parameter.');
 
-  const addr = parseAddress(str, this.network);
-
   if (name === '')
     name = 'default';
 
@@ -1277,20 +1276,18 @@ RPC.prototype.sendFrom = async function sendFrom(args, help) {
 };
 
 RPC.prototype.sendMany = async function sendMany(args, help) {
+  if (help || args.length < 2 || args.length > 5) {
+    throw new RPCError(errs.MISC_ERROR,
+      'sendmany "fromaccount" {"address":amount,...}'
+      + ' ( minconf "comment" ["address",...] )');
+  }
+
   const wallet = this.wallet;
   const valid = new Validator([args]);
   let name = valid.str(0);
   const sendTo = valid.obj(1);
   const minconf = valid.u32(2, 1);
   const subtractFee = valid.bool(4, false);
-  const uniq = new Set();
-  const outputs = [];
-
-  if (help || args.length < 2 || args.length > 5) {
-    throw new RPCError(errs.MISC_ERROR,
-      'sendmany "fromaccount" {"address":amount,...}'
-      + ' ( minconf "comment" ["address",...] )');
-  }
 
   if (name === '')
     name = 'default';
@@ -1299,6 +1296,8 @@ RPC.prototype.sendMany = async function sendMany(args, help) {
     throw new RPCError(errs.TYPE_ERROR, 'Invalid parameter.');
 
   const to = new Validator([sendTo]);
+  const uniq = new Set();
+  const outputs = [];
 
   for (const key of Object.keys(sendTo)) {
     const value = to.btc(key);
@@ -1332,18 +1331,18 @@ RPC.prototype.sendMany = async function sendMany(args, help) {
 };
 
 RPC.prototype.sendToAddress = async function sendToAddress(args, help) {
-  const wallet = this.wallet;
-  const valid = new Validator([args]);
-  const str = valid.str(0);
-  const value = valid.btc(1);
-  const subtractFee = valid.bool(4, false);
-
   if (help || args.length < 2 || args.length > 5) {
     throw new RPCError(errs.MISC_ERROR,
       'sendtoaddress "bitcoinaddress" amount'
       + ' ( "comment" "comment-to" subtractfeefromamount )');
   }
 
+  const wallet = this.wallet;
+  const valid = new Validator([args]);
+  const str = valid.str(0);
+  const value = valid.btc(1);
+  const subtractFee = valid.bool(4, false);
+
   const addr = parseAddress(str, this.network);
 
   if (!addr || value == null)
@@ -1389,16 +1388,16 @@ RPC.prototype.setTXFee = async function setTXFee(args, help) {
 };
 
 RPC.prototype.signMessage = async function signMessage(args, help) {
-  const wallet = this.wallet;
-  const valid = new Validator([args]);
-  const b58 = valid.str(0, '');
-  const str = valid.str(1, '');
-
   if (help || args.length !== 2) {
     throw new RPCError(errs.MISC_ERROR,
       'signmessage "bitcoinaddress" "message"');
   }
 
+  const wallet = this.wallet;
+  const valid = new Validator([args]);
+  const b58 = valid.str(0, '');
+  const str = valid.str(1, '');
+
   const addr = parseHash(b58, this.network);
 
   const ring = await wallet.getKey(addr);
@@ -1433,15 +1432,16 @@ RPC.prototype.walletLock = async function walletLock(args, help) {
 
 RPC.prototype.walletPassphraseChange = async function walletPassphraseChange(args, help) {
   const wallet = this.wallet;
-  const valid = new Validator([args]);
-  const old = valid.str(0, '');
-  const new_ = valid.str(1, '');
 
   if (help || (wallet.master.encrypted && args.length !== 2)) {
     throw new RPCError(errs.MISC_ERROR, 'walletpassphrasechange'
       + ' "oldpassphrase" "newpassphrase"');
   }
 
+  const valid = new Validator([args]);
+  const old = valid.str(0, '');
+  const new_ = valid.str(1, '');
+
   if (!wallet.master.encrypted)
     throw new RPCError(errs.WALLET_WRONG_ENC_STATE, 'Wallet is not encrypted.');
 
@@ -1479,15 +1479,15 @@ RPC.prototype.walletPassphrase = async function walletPassphrase(args, help) {
 };
 
 RPC.prototype.importPrunedFunds = async function importPrunedFunds(args, help) {
-  const valid = new Validator([args]);
-  const txRaw = valid.buf(0);
-  const blockRaw = valid.buf(1);
-
   if (help || args.length < 2 || args.length > 3) {
     throw new RPCError(errs.MISC_ERROR,
       'importprunedfunds "rawtransaction" "txoutproof" ( "label" )');
   }
 
+  const valid = new Validator([args]);
+  const txRaw = valid.buf(0);
+  const blockRaw = valid.buf(1);
+
   if (!txRaw || !blockRaw)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid parameter.');
 
@@ -1519,13 +1519,13 @@ RPC.prototype.importPrunedFunds = async function importPrunedFunds(args, help) {
 };
 
 RPC.prototype.removePrunedFunds = async function removePrunedFunds(args, help) {
+  if (help || args.length !== 1)
+    throw new RPCError(errs.MISC_ERROR, 'removeprunedfunds "txid"');
+
   const wallet = this.wallet;
   const valid = new Validator([args]);
   const hash = valid.hash(0);
 
-  if (help || args.length !== 1)
-    throw new RPCError(errs.MISC_ERROR, 'removeprunedfunds "txid"');
-
   if (!hash)
     throw new RPCError(errs.TYPE_ERROR, 'Invalid parameter.');
 
@@ -1560,12 +1560,12 @@ RPC.prototype.getMemoryInfo = async function getMemoryInfo(args, help) {
 };
 
 RPC.prototype.setLogLevel = async function setLogLevel(args, help) {
-  const valid = new Validator([args]);
-  const level = valid.str(0, '');
-
   if (help || args.length !== 1)
     throw new RPCError(errs.MISC_ERROR, 'setloglevel "level"');
 
+  const valid = new Validator([args]);
+  const level = valid.str(0, '');
+
   this.logger.setLevel(level);
 
   return null;
diff --git a/lib/wallet/server.js b/lib/wallet/server.js
index ae941049..d8bd4001 100644
--- a/lib/wallet/server.js
+++ b/lib/wallet/server.js
@@ -58,27 +58,6 @@ server.create = function create(options) {
     timeout: config.num('workers-timeout')
   });
 
-  workers.on('spawn', (child) => {
-    logger.info('Spawning worker process: %d.', child.id);
-  });
-
-  workers.on('exit', (code, child) => {
-    logger.warning('Worker %d exited: %s.', child.id, code);
-  });
-
-  workers.on('log', (text, child) => {
-    logger.debug('Worker %d says:', child.id);
-    logger.debug(text);
-  });
-
-  workers.on('error', (err, child) => {
-    if (child) {
-      logger.error('Worker %d error: %s', child.id, err.message);
-      return;
-    }
-    wdb.emit('error', err);
-  });
-
   const wdb = new WalletDB({
     network: config.network,
     logger: logger,
@@ -105,5 +84,26 @@ server.create = function create(options) {
 
   wdb.on('error', () => {});
 
+  workers.on('spawn', (child) => {
+    logger.info('Spawning worker process: %d.', child.id);
+  });
+
+  workers.on('exit', (code, child) => {
+    logger.warning('Worker %d exited: %s.', child.id, code);
+  });
+
+  workers.on('log', (text, child) => {
+    logger.debug('Worker %d says:', child.id);
+    logger.debug(text);
+  });
+
+  workers.on('error', (err, child) => {
+    if (child) {
+      logger.error('Worker %d error: %s', child.id, err.message);
+      return;
+    }
+    wdb.emit('error', err);
+  });
+
   return wdb;
 };
diff --git a/lib/wallet/txdb.js b/lib/wallet/txdb.js
index aa936ccd..bbbab793 100644
--- a/lib/wallet/txdb.js
+++ b/lib/wallet/txdb.js
@@ -221,8 +221,10 @@ TXDB.prototype.has = function has(key) {
 TXDB.prototype.range = function range(options) {
   if (options.gte)
     options.gte = this.prefix(options.gte);
+
   if (options.lte)
     options.lte = this.prefix(options.lte);
+
   return this.db.range(options);
 };
 
@@ -235,8 +237,10 @@ TXDB.prototype.range = function range(options) {
 TXDB.prototype.keys = function keys(options) {
   if (options.gte)
     options.gte = this.prefix(options.gte);
+
   if (options.lte)
     options.lte = this.prefix(options.lte);
+
   return this.db.keys(options);
 };
 
@@ -249,8 +253,10 @@ TXDB.prototype.keys = function keys(options) {
 TXDB.prototype.values = function values(options) {
   if (options.gte)
     options.gte = this.prefix(options.gte);
+
   if (options.lte)
     options.lte = this.prefix(options.lte);
+
   return this.db.values(options);
 };
 
@@ -260,13 +266,13 @@ TXDB.prototype.values = function values(options) {
  * @returns {Promise} - Returns {@link Path}.
  */
 
-TXDB.prototype.getPath = function getPath(output) {
+TXDB.prototype.getPath = async function getPath(output) {
   const addr = output.getAddress();
 
   if (!addr)
-    return Promise.resolve();
+    return null;
 
-  return this.wallet.getPath(addr);
+  return await this.wallet.getPath(addr);
 };
 
 /**
@@ -275,13 +281,13 @@ TXDB.prototype.getPath = function getPath(output) {
  * @returns {Promise} - Returns Boolean.
  */
 
-TXDB.prototype.hasPath = function hasPath(output) {
+TXDB.prototype.hasPath = async function hasPath(output) {
   const addr = output.getAddress();
 
   if (!addr)
-    return Promise.resolve(false);
+    return false;
 
-  return this.wallet.hasPath(addr);
+  return await this.wallet.hasPath(addr);
 };
 
 /**
@@ -427,8 +433,7 @@ TXDB.prototype.resolveInput = async function resolveInput(tx, index, height, pat
  */
 
 TXDB.prototype.isDoubleSpend = async function isDoubleSpend(tx) {
-  for (const input of tx.inputs) {
-    const prevout = input.prevout;
+  for (const {prevout} of tx.inputs) {
     const spent = await this.isSpent(prevout.hash, prevout.index);
     if (spent)
       return true;
@@ -448,9 +453,9 @@ TXDB.prototype.isRBF = async function isRBF(tx) {
   if (tx.isRBF())
     return true;
 
-  for (const input of tx.inputs) {
-    const prevout = input.prevout;
-    if (await this.has(layout.r(prevout.hash)))
+  for (const {prevout} of tx.inputs) {
+    const key = layout.r(prevout.hash);
+    if (await this.has(key))
       return true;
   }
 
@@ -468,7 +473,7 @@ TXDB.prototype.getSpent = async function getSpent(hash, index) {
   const data = await this.get(layout.s(hash, index));
 
   if (!data)
-    return;
+    return null;
 
   return Outpoint.fromRaw(data);
 };
@@ -593,7 +598,7 @@ TXDB.prototype.getBlock = async function getBlock(height) {
   const data = await this.get(layout.b(height));
 
   if (!data)
-    return;
+    return null;
 
   return BlockRecord.fromRaw(data);
 };
@@ -710,7 +715,6 @@ TXDB.prototype.add = async function add(tx, block) {
   this.start();
 
   let result;
-
   try {
     result = await this._add(tx, block);
   } catch (e) {
@@ -739,12 +743,12 @@ TXDB.prototype._add = async function add(tx, block) {
   if (existing) {
     // Existing tx is already confirmed. Ignore.
     if (existing.height !== -1)
-      return;
+      return null;
 
     // The incoming tx won't confirm the
     // existing one anyway. Ignore.
     if (!block)
-      return;
+      return null;
 
     // Confirm transaction.
     return await this._confirm(existing, block);
@@ -760,13 +764,13 @@ TXDB.prototype._add = async function add(tx, block) {
       // hash to detect "passive"
       // replace-by-fee.
       this.put(layout.r(hash), null);
-      return;
+      return null;
     }
 
     // Potentially remove double-spenders.
     // Only remove if they're not confirmed.
     if (!(await this.removeConflicts(tx, true)))
-      return;
+      return null;
   } else {
     // Potentially remove double-spenders.
     await this.removeConflicts(tx, false);
@@ -825,7 +829,7 @@ TXDB.prototype.insert = async function insert(wtx, block) {
       if (!block) {
         if (!(await this.verifyInput(tx, i, coin))) {
           this.clear();
-          return;
+          return null;
         }
       }
 
@@ -911,7 +915,7 @@ TXDB.prototype.insert = async function insert(wtx, block) {
   if (!updated) {
     // Clear the spent list inserts.
     this.clear();
-    return;
+    return null;
   }
 
   // Save and index the transaction record.
@@ -976,7 +980,7 @@ TXDB.prototype.confirm = async function confirm(hash, block) {
   const wtx = await this.getTX(hash);
 
   if (!wtx)
-    return;
+    return null;
 
   if (wtx.height !== -1)
     throw new Error('TX is already confirmed.');
@@ -1139,7 +1143,7 @@ TXDB.prototype.remove = async function remove(hash) {
   const wtx = await this.getTX(hash);
 
   if (!wtx)
-    return;
+    return null;
 
   return await this.removeRecursive(wtx);
 };
@@ -1310,7 +1314,6 @@ TXDB.prototype.unconfirm = async function unconfirm(hash) {
   this.start();
 
   let details;
-
   try {
     details = await this._unconfirm(hash);
   } catch (e) {
@@ -1334,10 +1337,10 @@ TXDB.prototype._unconfirm = async function unconfirm(hash) {
   const wtx = await this.getTX(hash);
 
   if (!wtx)
-    return;
+    return null;
 
   if (wtx.height === -1)
-    return;
+    return null;
 
   return await this.disconnect(wtx, wtx.getBlock());
 };
@@ -1546,8 +1549,10 @@ TXDB.prototype.removeConflicts = async function removeConflicts(tx, conf) {
 
 TXDB.prototype.verifyInput = async function verifyInput(tx, index, coin) {
   const flags = Script.flags.MANDATORY_VERIFY_FLAGS;
+
   if (!this.options.verify)
     return true;
+
   return await tx.verifyInputAsync(index, coin, flags);
 };
 
@@ -2034,16 +2039,15 @@ TXDB.prototype.getAccountCredits = async function getAccountCredits(account) {
  */
 
 TXDB.prototype.getSpentCredits = async function getSpentCredits(tx) {
+  if (tx.isCoinbase())
+    return [];
+
+  const hash = tx.hash('hex');
   const credits = [];
 
   for (let i = 0; i < tx.inputs.length; i++)
     credits.push(null);
 
-  if (tx.isCoinbase())
-    return credits;
-
-  const hash = tx.hash('hex');
-
   await this.range({
     gte: layout.d(hash, 0x00000000),
     lte: layout.d(hash, 0xffffffff),
@@ -2108,12 +2112,11 @@ TXDB.prototype.getAccountCoins = async function getAccountCoins(account) {
  */
 
 TXDB.prototype.getSpentCoins = async function getSpentCoins(tx) {
-  const coins = [];
-
   if (tx.isCoinbase())
-    return coins;
+    return [];
 
   const credits = await this.getSpentCredits(tx);
+  const coins = [];
 
   for (const credit of credits) {
     if (!credit) {
@@ -2185,7 +2188,7 @@ TXDB.prototype.getState = async function getState() {
   const data = await this.get(layout.R);
 
   if (!data)
-    return;
+    return null;
 
   return TXDBState.fromRaw(this.wallet.wid, this.wallet.id, data);
 };
@@ -2200,7 +2203,7 @@ TXDB.prototype.getTX = async function getTX(hash) {
   const raw = await this.get(layout.t(hash));
 
   if (!raw)
-    return;
+    return null;
 
   return TXRecord.fromRaw(raw);
 };
@@ -2215,7 +2218,7 @@ TXDB.prototype.getDetails = async function getDetails(hash) {
   const wtx = await this.getTX(hash);
 
   if (!wtx)
-    return;
+    return null;
 
   return await this.toDetails(wtx);
 };
@@ -2297,7 +2300,7 @@ TXDB.prototype.getCoin = async function getCoin(hash, index) {
   const credit = await this.getCredit(hash, index);
 
   if (!credit)
-    return;
+    return null;
 
   return credit.coin;
 };
@@ -2312,19 +2315,19 @@ TXDB.prototype.getCoin = async function getCoin(hash, index) {
 TXDB.prototype.getCredit = async function getCredit(hash, index) {
   const state = this.state;
   const key = Outpoint.toKey(hash, index);
-  let data = this.coinCache.get(key);
+  const cache = this.coinCache.get(key);
 
-  if (data) {
-    const credit = Credit.fromRaw(data);
+  if (cache) {
+    const credit = Credit.fromRaw(cache);
     credit.coin.hash = hash;
     credit.coin.index = index;
     return credit;
   }
 
-  data = await this.get(layout.c(hash, index));
+  const data = await this.get(layout.c(hash, index));
 
   if (!data)
-    return;
+    return null;
 
   const credit = Credit.fromRaw(data);
   credit.coin.hash = hash;
@@ -2347,7 +2350,7 @@ TXDB.prototype.getSpentCoin = async function getSpentCoin(spent, prevout) {
   const data = await this.get(layout.d(spent.hash, spent.index));
 
   if (!data)
-    return;
+    return null;
 
   const coin = Coin.fromRaw(data);
   coin.hash = prevout.hash;
@@ -2397,13 +2400,13 @@ TXDB.prototype.updateSpentCoin = async function updateSpentCoin(tx, index, heigh
  * @returns {Promise} - Returns Boolean.
  */
 
-TXDB.prototype.hasCoin = function hasCoin(hash, index) {
+TXDB.prototype.hasCoin = async function hasCoin(hash, index) {
   const key = Outpoint.toKey(hash, index);
 
   if (this.coinCache.has(key))
-    return Promise.resolve(true);
+    return true;
 
-  return this.has(layout.c(hash, index));
+  return await this.has(layout.c(hash, index));
 };
 
 /**
@@ -2475,16 +2478,17 @@ TXDB.prototype.getAccountBalance = async function getAccountBalance(account) {
  */
 
 TXDB.prototype.zap = async function zap(account, age) {
-  const hashes = [];
-  const now = util.now();
-
   assert(util.isUInt32(age));
 
+  const now = util.now();
+
   const txs = await this.getRange(account, {
     start: 0,
     end: now - age
   });
 
+  const hashes = [];
+
   for (const wtx of txs) {
     if (wtx.height !== -1)
       continue;
diff --git a/lib/wallet/wallet.js b/lib/wallet/wallet.js
index a64856f9..eeee26e4 100644
--- a/lib/wallet/wallet.js
+++ b/lib/wallet/wallet.js
@@ -291,7 +291,6 @@ Wallet.prototype._addSharedKey = async function addSharedKey(acct, key) {
   this.start();
 
   let result;
-
   try {
     result = await account.addSharedKey(key);
   } catch (e) {
@@ -345,7 +344,6 @@ Wallet.prototype._removeSharedKey = async function removeSharedKey(acct, key) {
   this.start();
 
   let result;
-
   try {
     result = await account.removeSharedKey(key);
   } catch (e) {
@@ -611,20 +609,20 @@ Wallet.prototype.getID = function getID() {
 
   const key = this.master.key.derive(44);
 
-  let bw = new StaticWriter(37);
+  const bw = new StaticWriter(37);
   bw.writeBytes(key.publicKey);
   bw.writeU32(this.network.magic);
 
   const hash = digest.hash160(bw.render());
 
-  bw = new StaticWriter(27);
-  bw.writeU8(0x03);
-  bw.writeU8(0xbe);
-  bw.writeU8(0x04);
-  bw.writeBytes(hash);
-  bw.writeChecksum();
+  const b58 = new StaticWriter(27);
+  b58.writeU8(0x03);
+  b58.writeU8(0xbe);
+  b58.writeU8(0x04);
+  b58.writeBytes(hash);
+  b58.writeChecksum();
 
-  return base58.encode(bw.render());
+  return base58.encode(b58.render());
 };
 
 /**
@@ -681,7 +679,6 @@ Wallet.prototype._createAccount = async function createAccount(options, passphra
   await this.unlock(passphrase);
 
   let key;
-
   if (this.watchOnly && options.accountKey) {
     key = options.accountKey;
 
@@ -699,7 +696,7 @@ Wallet.prototype._createAccount = async function createAccount(options, passphra
     key = key.toPublic();
   }
 
-  options = {
+  const opt = {
     wid: this.wid,
     id: this.id,
     name: this.accountDepth === 0 ? 'default' : name,
@@ -716,9 +713,8 @@ Wallet.prototype._createAccount = async function createAccount(options, passphra
   this.start();
 
   let account;
-
   try {
-    account = Account.fromOptions(this.db, options);
+    account = Account.fromOptions(this.db, opt);
     account.wallet = this;
     await account.init();
   } catch (e) {
@@ -802,7 +798,7 @@ Wallet.prototype.getAccount = async function getAccount(acct) {
   const index = await this.getAccountIndex(acct);
 
   if (index === -1)
-    return;
+    return null;
 
   const unlock = await this.readLock.lock(index);
 
@@ -820,15 +816,15 @@ Wallet.prototype.getAccount = async function getAccount(acct) {
  */
 
 Wallet.prototype._getAccount = async function getAccount(index) {
-  let account = this.accountCache.get(index);
+  const cache = this.accountCache.get(index);
 
-  if (account)
-    return account;
+  if (cache)
+    return cache;
 
-  account = await this.db.getAccount(this.wid, index);
+  const account = await this.db.getAccount(this.wid, index);
 
   if (!account)
-    return;
+    return null;
 
   account.wallet = this;
   account.wid = this.wid;
@@ -856,12 +852,12 @@ Wallet.prototype.getAccountIndex = async function getAccountIndex(name) {
   if (typeof name === 'number')
     return name;
 
-  let index = this.indexCache.get(name);
+  const cache = this.indexCache.get(name);
 
-  if (index != null)
-    return index;
+  if (cache != null)
+    return cache;
 
-  index = await this.db.getAccountIndex(this.wid, name);
+  const index = await this.db.getAccountIndex(this.wid, name);
 
   if (index === -1)
     return -1;
@@ -979,7 +975,6 @@ Wallet.prototype._createKey = async function createKey(acct, branch) {
   this.start();
 
   let result;
-
   try {
     result = await account.createKey(branch);
   } catch (e) {
@@ -1060,7 +1055,7 @@ Wallet.prototype.getPath = async function getPath(address) {
   const path = await this.readPath(address);
 
   if (!path)
-    return;
+    return null;
 
   path.name = await this.getAccountName(path.account);
 
@@ -1080,15 +1075,15 @@ Wallet.prototype.getPath = async function getPath(address) {
 
 Wallet.prototype.readPath = async function readPath(address) {
   const hash = Address.getHash(address, 'hex');
-  let path = this.pathCache.get(hash);
+  const cache = this.pathCache.get(hash);
 
-  if (path)
-    return path;
+  if (cache)
+    return cache;
 
-  path = await this.db.getPath(this.wid, hash);
+  const path = await this.db.getPath(this.wid, hash);
 
   if (!path)
-    return;
+    return null;
 
   path.id = this.id;
 
@@ -1147,10 +1142,11 @@ Wallet.prototype.getAccountPaths = async function getAccountPaths(acct) {
   const index = await this.ensureIndex(acct, true);
   const hashes = await this.getAccountHashes(index);
   const name = await this.getAccountName(acct);
-  const result = [];
 
   assert(name);
 
+  const result = [];
+
   for (const hash of hashes) {
     const path = await this.readPath(hash);
 
@@ -1230,9 +1226,8 @@ Wallet.prototype._importKey = async function importKey(acct, ring, passphrase) {
 
   await this.unlock(passphrase);
 
-  ring = WalletKey.fromRing(account, ring);
-
-  const path = ring.toPath();
+  const key = WalletKey.fromRing(account, ring);
+  const path = key.toPath();
 
   if (this.master.encrypted) {
     path.data = this.master.encipher(path.data, path.hash);
@@ -1370,7 +1365,6 @@ Wallet.prototype._fund = async function fund(mtx, options) {
     throw new Error('Cannot fund from watch-only wallet.');
 
   let account;
-
   if (options.account != null) {
     account = await this.getAccount(options.account);
     if (!account)
@@ -1383,12 +1377,10 @@ Wallet.prototype._fund = async function fund(mtx, options) {
     throw new Error('Account is not initialized.');
 
   let rate = options.rate;
-
   if (rate == null)
     rate = await this.db.estimateFee(options.blocks);
 
   let coins;
-
   if (options.smart) {
     coins = await this.getSmartCoins(options.account);
   } else {
@@ -1423,7 +1415,7 @@ Wallet.prototype.getAccountByAddress = async function getAccountByAddress(addres
   const path = await this.getPath(hash);
 
   if (!path)
-    return;
+    return null;
 
   return await this.getAccount(path.account);
 };
@@ -1627,10 +1619,10 @@ Wallet.prototype._send = async function send(options, passphrase) {
  */
 
 Wallet.prototype.increaseFee = async function increaseFee(hash, rate, passphrase) {
-  const wtx = await this.getTX(hash);
-
   assert(util.isUInt32(rate), 'Rate must be a number.');
 
+  const wtx = await this.getTX(hash);
+
   if (!wtx)
     throw new Error('Transaction not found.');
 
@@ -1728,11 +1720,12 @@ Wallet.prototype.increaseFee = async function increaseFee(hash, rate, passphrase
 
 Wallet.prototype.resend = async function resend() {
   const wtxs = await this.getPending();
-  const txs = [];
 
   if (wtxs.length > 0)
     this.logger.info('Rebroadcasting %d transactions.', wtxs.length);
 
+  const txs = [];
+
   for (const wtx of wtxs)
     txs.push(wtx.tx);
 
@@ -1783,12 +1776,12 @@ Wallet.prototype.getKey = async function getKey(address) {
   const path = await this.getPath(hash);
 
   if (!path)
-    return;
+    return null;
 
   const account = await this.getAccount(path.account);
 
   if (!account)
-    return;
+    return null;
 
   return account.derivePath(path, this.master);
 };
@@ -1806,19 +1799,19 @@ Wallet.prototype.getPrivateKey = async function getPrivateKey(address, passphras
   const path = await this.getPath(hash);
 
   if (!path)
-    return;
+    return null;
 
   const account = await this.getAccount(path.account);
 
   if (!account)
-    return;
+    return null;
 
   await this.unlock(passphrase);
 
   const key = account.derivePath(path, this.master);
 
   if (!key.privateKey)
-    return;
+    return null;
 
   return key;
 };
@@ -1830,14 +1823,13 @@ Wallet.prototype.getPrivateKey = async function getPrivateKey(address, passphras
  */
 
 Wallet.prototype.getInputPaths = async function getInputPaths(mtx) {
-  const paths = [];
-
   assert(mtx.mutable);
 
   if (!mtx.hasCoins())
     throw new Error('Not all coins available.');
 
   const hashes = mtx.getInputHashes('hex');
+  const paths = [];
 
   for (const hash of hashes) {
     const path = await this.getPath(hash);
@@ -1927,10 +1919,6 @@ Wallet.prototype._setLookahead = async function setLookahead(acct, lookahead) {
 
 Wallet.prototype.syncOutputDepth = async function syncOutputDepth(details) {
   const map = new Map();
-  const derived = [];
-
-  if (!details)
-    return derived;
 
   for (const output of details.outputs) {
     const path = output.path;
@@ -1947,6 +1935,8 @@ Wallet.prototype.syncOutputDepth = async function syncOutputDepth(details) {
     map.get(path.account).push(path);
   }
 
+  const derived = [];
+
   for (const [acct, paths] of map) {
     let receive = -1;
     let change = -1;
@@ -1998,7 +1988,7 @@ Wallet.prototype.getRedeem = async function getRedeem(hash) {
   const ring = await this.getKey(hash.toString('hex'));
 
   if (!ring)
-    return;
+    return null;
 
   return ring.getRedeem(hash);
 };
@@ -2146,7 +2136,8 @@ Wallet.prototype._add = async function add(tx, block) {
   let details, derived;
   try {
     details = await this.txdb._add(tx, block);
-    derived = await this.syncOutputDepth(details);
+    if (details)
+      derived = await this.syncOutputDepth(details);
   } catch (e) {
     this.txdb.drop();
     throw e;
@@ -2154,7 +2145,7 @@ Wallet.prototype._add = async function add(tx, block) {
 
   await this.txdb.commit();
 
-  if (derived.length > 0) {
+  if (derived && derived.length > 0) {
     this.db.emit('address', this.id, derived);
     this.emit('address', derived);
   }
diff --git a/lib/wallet/walletdb.js b/lib/wallet/walletdb.js
index 131fa3b7..a1aff965 100644
--- a/lib/wallet/walletdb.js
+++ b/lib/wallet/walletdb.js
@@ -313,7 +313,6 @@ WalletDB.prototype.init = async function init() {
   }
 
   let tip;
-
   if (this.client) {
     if (startHeight != null) {
       tip = await this.client.getEntry(startHeight);
@@ -403,12 +402,12 @@ WalletDB.prototype.watch = async function watch() {
  */
 
 WalletDB.prototype.sync = async function sync() {
-  let height = this.state.height;
-  let entry;
-
   if (!this.client)
     return;
 
+  let height = this.state.height;
+  let entry;
+
   while (height >= 0) {
     const tip = await this.getBlock(height);
 
@@ -590,8 +589,6 @@ WalletDB.prototype.backup = function backup(path) {
  */
 
 WalletDB.prototype.wipe = async function wipe() {
-  const batch = this.db.batch();
-
   this.logger.warning('Wiping WalletDB TXDB...');
   this.logger.warning('I hope you know what you\'re doing.');
 
@@ -600,6 +597,7 @@ WalletDB.prototype.wipe = async function wipe() {
     lte: Buffer.from([0xff])
   });
 
+  const batch = this.db.batch();
   let total = 0;
 
   for (;;) {
@@ -816,22 +814,22 @@ WalletDB.prototype.unregister = function unregister(wallet) {
 
 WalletDB.prototype.getWalletID = async function getWalletID(id) {
   if (!id)
-    return;
+    return null;
 
   if (typeof id === 'number')
     return id;
 
-  let wid = this.widCache.get(id);
+  const cache = this.widCache.get(id);
 
-  if (wid)
-    return wid;
+  if (cache)
+    return cache;
 
   const data = await this.db.get(layout.l(id));
 
   if (!data)
-    return;
+    return null;
 
-  wid = data.readUInt32LE(0, true);
+  const wid = data.readUInt32LE(0, true);
 
   this.widCache.set(id, wid);
 
@@ -848,7 +846,7 @@ WalletDB.prototype.get = async function get(id) {
   const wid = await this.getWalletID(id);
 
   if (!wid)
-    return;
+    return null;
 
   const unlock = await this.readLock.lock(wid);
 
@@ -867,17 +865,17 @@ WalletDB.prototype.get = async function get(id) {
  */
 
 WalletDB.prototype._get = async function get(wid) {
-  let wallet = this.wallets.get(wid);
+  const cache = this.wallets.get(wid);
 
-  if (wallet)
-    return wallet;
+  if (cache)
+    return cache;
 
   const data = await this.db.get(layout.w(wid));
 
   if (!data)
-    return;
+    return null;
 
-  wallet = Wallet.fromRaw(this, data);
+  const wallet = Wallet.fromRaw(this, data);
 
   await wallet.open();
 
@@ -981,7 +979,7 @@ WalletDB.prototype.auth = async function auth(wid, token) {
   const wallet = await this.get(wid);
 
   if (!wallet)
-    return;
+    return null;
 
   if (typeof token === 'string') {
     if (!util.isHex256(token))
@@ -1059,8 +1057,10 @@ WalletDB.prototype.has = async function has(id) {
 
 WalletDB.prototype.ensure = async function ensure(options) {
   const wallet = await this.get(options.id);
+
   if (wallet)
     return wallet;
+
   return await this.create(options);
 };
 
@@ -1076,7 +1076,7 @@ WalletDB.prototype.getAccount = async function getAccount(wid, index) {
   const data = await this.db.get(layout.a(wid, index));
 
   if (!data)
-    return;
+    return null;
 
   return Account.fromRaw(this, data);
 };
@@ -1122,7 +1122,7 @@ WalletDB.prototype.getAccountName = async function getAccountName(wid, index) {
   const name = await this.db.get(layout.n(wid, index));
 
   if (!name)
-    return;
+    return null;
 
   return name.toString('ascii');
 };
@@ -1171,17 +1171,17 @@ WalletDB.prototype.hasAccount = function hasAccount(wid, index) {
  */
 
 WalletDB.prototype.getPathMap = async function getPathMap(hash) {
-  let map = this.pathMapCache.get(hash);
+  const cache = this.pathMapCache.get(hash);
 
-  if (map)
-    return map;
+  if (cache)
+    return cache;
 
   const data = await this.db.get(layout.p(hash));
 
   if (!data)
-    return;
+    return null;
 
-  map = PathMapRecord.fromRaw(hash, data);
+  const map = PathMapRecord.fromRaw(hash, data);
 
   this.pathMapCache.set(hash, map);
 
@@ -1251,7 +1251,7 @@ WalletDB.prototype.getPath = async function getPath(wid, hash) {
   const data = await this.db.get(layout.P(wid, hash));
 
   if (!data)
-    return;
+    return null;
 
   const path = Path.fromRaw(data);
   path.wid = wid;
@@ -1336,13 +1336,13 @@ WalletDB.prototype.getAccountHashes = function getAccountHashes(wid, account) {
  */
 
 WalletDB.prototype.getWalletPaths = async function getWalletPaths(wid) {
-  const paths = [];
-
   const items = await this.db.range({
     gte: layout.P(wid, encoding.NULL_HASH),
     lte: layout.P(wid, encoding.HIGH_HASH)
   });
 
+  const paths = [];
+
   for (const item of items) {
     const hash = layout.Pp(item.key);
     const path = Path.fromRaw(item.value);
@@ -1536,7 +1536,7 @@ WalletDB.prototype.getWalletsByTX = async function getWalletsByTX(tx) {
   }
 
   if (result.size === 0)
-    return;
+    return null;
 
   return result;
 };
@@ -1550,7 +1550,7 @@ WalletDB.prototype.getState = async function getState() {
   const data = await this.db.get(layout.R);
 
   if (!data)
-    return;
+    return null;
 
   return ChainState.fromRaw(data);
 };
@@ -1668,7 +1668,7 @@ WalletDB.prototype.getBlockMap = async function getBlockMap(height) {
   const data = await this.db.get(layout.b(height));
 
   if (!data)
-    return;
+    return null;
 
   return BlockMapRecord.fromRaw(height, data);
 };
@@ -1707,7 +1707,7 @@ WalletDB.prototype.getOutpointMap = async function getOutpointMap(hash, index) {
   const data = await this.db.get(layout.o(hash, index));
 
   if (!data)
-    return;
+    return null;
 
   return OutpointMapRecord.fromRaw(hash, index, data);
 };
@@ -1750,7 +1750,7 @@ WalletDB.prototype.getBlock = async function getBlock(height) {
   const data = await this.db.get(layout.h(height));
 
   if (!data)
-    return;
+    return null;
 
   const block = new BlockMeta();
   block.hash = data.toString('hex');
@@ -2055,7 +2055,7 @@ WalletDB.prototype._insert = async function insert(tx, block) {
   assert(!tx.mutable, 'WDB: Cannot add mutable TX.');
 
   if (!wids)
-    return;
+    return null;
 
   this.logger.info(
     'Incoming transaction for %d wallets in WalletDB (%s).',
@@ -2082,7 +2082,7 @@ WalletDB.prototype._insert = async function insert(tx, block) {
   }
 
   if (!result)
-    return;
+    return null;
 
   return wids;
 };
diff --git a/lib/workers/parser.js b/lib/workers/parser.js
index f98fd76f..f9c9672f 100644
--- a/lib/workers/parser.js
+++ b/lib/workers/parser.js
@@ -43,35 +43,32 @@ Parser.prototype.feed = function feed(data) {
 };
 
 Parser.prototype.read = function read(size) {
-  let pending, chunk, off, len;
-
   assert(this.total >= size, 'Reading too much.');
 
   if (size === 0)
     return Buffer.alloc(0);
 
-  pending = this.pending[0];
+  const pending = this.pending[0];
 
   if (pending.length > size) {
-    chunk = pending.slice(0, size);
+    const chunk = pending.slice(0, size);
     this.pending[0] = pending.slice(size);
     this.total -= chunk.length;
     return chunk;
   }
 
   if (pending.length === size) {
-    chunk = this.pending.shift();
+    const chunk = this.pending.shift();
     this.total -= chunk.length;
     return chunk;
   }
 
-  chunk = Buffer.allocUnsafe(size);
-  off = 0;
-  len = 0;
+  const chunk = Buffer.allocUnsafe(size);
+  let off = 0;
 
   while (off < chunk.length) {
-    pending = this.pending[0];
-    len = pending.copy(chunk, off);
+    const pending = this.pending[0];
+    const len = pending.copy(chunk, off);
     if (len === pending.length)
       this.pending.shift();
     else
@@ -88,7 +85,6 @@ Parser.prototype.read = function read(size) {
 
 Parser.prototype.parse = function parse(data) {
   let header = this.header;
-  let packet;
 
   if (!header) {
     try {
@@ -107,6 +103,7 @@ Parser.prototype.parse = function parse(data) {
   this.waiting = 9;
   this.header = null;
 
+  let packet;
   try {
     packet = this.parsePacket(header, data);
   } catch (e) {
diff --git a/migrate/chaindb2to3.js b/migrate/chaindb2to3.js
index e9405923..9e830b74 100644
--- a/migrate/chaindb2to3.js
+++ b/migrate/chaindb2to3.js
@@ -563,6 +563,9 @@ function bpair(prefix, hash, index) {
   return key;
 }
 
+// Make eslint happy.
+reserializeEntries;
+
 (async () => {
   await db.open();
 
diff --git a/migrate/walletdb4to5.js b/migrate/walletdb4to5.js
index eb0e58f6..9a767607 100644
--- a/migrate/walletdb4to5.js
+++ b/migrate/walletdb4to5.js
@@ -26,7 +26,7 @@ async function updateVersion() {
   const data = await db.get('V');
   assert(data, 'No version.');
 
-  ver = data.readUInt32LE(0, true);
+  let ver = data.readUInt32LE(0, true);
 
   if (ver !== 4)
     throw Error(`DB is version ${ver}.`);
@@ -35,7 +35,7 @@ async function updateVersion() {
 
   await db.backup(bak);
 
-  let ver = Buffer.allocUnsafe(4);
+  ver = Buffer.allocUnsafe(4);
   ver.writeUInt32LE(5, 0, true);
   batch.put('V', ver);
 }
diff --git a/migrate/walletdb5to6.js b/migrate/walletdb5to6.js
index 656a0675..353cf4a1 100644
--- a/migrate/walletdb5to6.js
+++ b/migrate/walletdb5to6.js
@@ -29,7 +29,7 @@ async function updateVersion() {
   const data = await db.get('V');
   assert(data, 'No version.');
 
-  ver = data.readUInt32LE(0, true);
+  let ver = data.readUInt32LE(0, true);
 
   if (ver !== 5)
     throw Error(`DB is version ${ver}.`);
@@ -38,7 +38,7 @@ async function updateVersion() {
 
   await db.backup(bak);
 
-  let ver = Buffer.allocUnsafe(4);
+  ver = Buffer.allocUnsafe(4);
   ver.writeUInt32LE(6, 0, true);
   batch.put('V', ver);
 }
diff --git a/test/util/memwallet.js b/test/util/memwallet.js
index 2345b0f4..30e7061b 100644
--- a/test/util/memwallet.js
+++ b/test/util/memwallet.js
@@ -146,7 +146,7 @@ MemWallet.prototype.deriveKey = function deriveKey(branch, index) {
 MemWallet.prototype.getKey = function getKey(hash) {
   const path = this.paths.get(hash);
   if (!path)
-    return;
+    return null;
   return this.derivePath(path);
 };