refactor: remove all duck typing.

lib/blockchain/chainentry.js

@@ -538,9 +538,7 @@ ChainEntry.prototype.inspect = function inspect() {
  */
 
 ChainEntry.isChainEntry = function isChainEntry(obj) {
-  return obj
-    && BN.isBN(obj.chainwork)
-    && typeof obj.getMedianTime === 'function';
+  return obj instanceof ChainEntry;
 };
 
 /*

lib/hd/mnemonic.js

@@ -554,9 +554,7 @@ Mnemonic.prototype.inspect = function inspect() {
  */
 
 Mnemonic.isMnemonic = function isMnemonic(obj) {
-  return obj
-    && typeof obj.bits === 'number'
-    && typeof obj.toSeed === 'function';
+  return obj instanceof Mnemonic;
 };
 
 /**

lib/hd/private.js

@@ -742,10 +742,7 @@ HDPrivateKey.fromJSON = function fromJSON(json, network) {
  */
 
 HDPrivateKey.isHDPrivateKey = function isHDPrivateKey(obj) {
-  return obj
-    && typeof obj.derive === 'function'
-    && typeof obj.fromMnemonic === 'function'
-    && Buffer.isBuffer(obj.chainCode);
+  return obj instanceof HDPrivateKey;
 };
 
 /*

lib/hd/public.js

@@ -561,10 +561,7 @@ HDPublicKey.fromRaw = function fromRaw(data, network) {
  */
 
 HDPublicKey.isHDPublicKey = function isHDPublicKey(obj) {
-  return obj
-    && typeof obj.derive === 'function'
-    && obj.fromMnemonic === undefined
-    && Buffer.isBuffer(obj.chainCode);
+  return obj instanceof HDPublicKey;
 };
 
 /*

lib/primitives/block.js

@@ -818,9 +818,7 @@ Block.prototype.getWitnessSizes = function getWitnessSizes() {
  */
 
 Block.isBlock = function isBlock(obj) {
-  return obj
-    && typeof obj.merkleRoot === 'string'
-    && typeof obj.getClaimed === 'function';
+  return obj instanceof Block;
 };
 
 /*

lib/primitives/coin.js

@@ -424,10 +424,7 @@ Coin.fromTX = function fromTX(tx, index, height) {
  */
 
 Coin.isCoin = function isCoin(obj) {
-  return obj
-    && typeof obj.version === 'number'
-    && typeof obj.script === 'object'
-    && typeof obj.getDepth === 'function';
+  return obj instanceof Coin;
 };
 
 /*

lib/primitives/headers.js

@@ -266,10 +266,7 @@ Headers.prototype.format = function format(view, height) {
  */
 
 Headers.isHeaders = function isHeaders(obj) {
-  return obj
-    && !obj.txs
-    && typeof obj.toHead === 'function'
-    && typeof obj.toBlock !== 'function';
+  return obj instanceof Headers;
 };
 
 /*

lib/primitives/keyring.js

@@ -950,9 +950,7 @@ KeyRing.fromRaw = function fromRaw(data) {
  */
 
 KeyRing.isKeyRing = function isKeyRing(obj) {
-  return obj
-    && Buffer.isBuffer(obj.publicKey)
-    && typeof obj.toSecret === 'function';
+  return obj instanceof KeyRing;
 };
 
 /*

lib/primitives/memblock.js

@@ -211,10 +211,7 @@ MemBlock.prototype.toHeaders = function toHeaders() {
  */
 
 MemBlock.isMemBlock = function isMemBlock(obj) {
-  return obj
-    && typeof obj.toBlock === 'function'
-    && typeof obj.isMemory === 'function'
-    && obj.isMemory();
+  return obj instanceof MemBlock;
 };
 
 /*

lib/primitives/merkleblock.js

@@ -637,9 +637,7 @@ MerkleBlock.fromMatches = function fromMatches(block, matches) {
  */
 
 MerkleBlock.isMerkleBlock = function isMerkleBlock(obj) {
-  return obj
-    && Buffer.isBuffer(obj.flags)
-    && typeof obj.verifyBody === 'function';
+  return obj instanceof MerkleBlock;
 };
 
 /**

lib/primitives/txmeta.js

@@ -292,10 +292,7 @@ TXMeta.fromRaw = function fromRaw(data, enc) {
  */
 
 TXMeta.isTXMeta = function isTXMeta(obj) {
-  return obj
-    && Array.isArray(obj.inputs)
-    && typeof obj.locktime === 'number'
-    && typeof obj.mtime === 'number';
+  return obj instanceof TXMeta;
 };
 
 /*

lib/protocol/network.js

@@ -367,9 +367,7 @@ Network.prototype.inspect = function inspect() {
  */
 
 Network.isNetwork = function isNetwork(obj) {
-  return obj
-    && typeof obj.genesisBlock === 'string'
-    && typeof obj.pow === 'object';
+  return obj instanceof Network;
 };
 
 /*

lib/wallet/account.js

@@ -994,9 +994,7 @@ Account.fromRaw = function fromRaw(db, data) {
  */
 
 Account.isAccount = function isAccount(obj) {
-  return obj
-    && typeof obj.receiveDepth === 'number'
-    && obj.deriveKey === 'function';
+  return obj instanceof Account;
 };
 
 /*

lib/wallet/masterkey.js

@@ -692,9 +692,7 @@ MasterKey.prototype.inspect = function inspect() {
  */
 
 MasterKey.isMasterKey = function isMasterKey(obj) {
-  return obj
-    && typeof obj.encrypted === 'boolean'
-    && typeof obj.decrypt === 'function';
+  return obj instanceof MasterKey;
 };
 
 /*

lib/wallet/wallet.js

@@ -2584,9 +2584,7 @@ Wallet.fromRaw = function fromRaw(db, data) {
  */
 
 Wallet.isWallet = function isWallet(obj) {
-  return obj
-    && typeof obj.accountDepth === 'number'
-    && obj.template === 'function';
+  return obj instanceof Wallet;
 };
 
 /*

lib/wallet/walletkey.js

@@ -294,10 +294,7 @@ WalletKey.prototype.toPath = function toPath() {
  */
 
 WalletKey.isWalletKey = function isWalletKey(obj) {
-  return obj
-    && Buffer.isBuffer(obj.publicKey)
-    && typeof obj.index === 'number'
-    && typeof obj.toPath === 'function';
+  return obj instanceof WalletKey;
 };
 
 /*