remove delete calls.

lib/bcoin/bst.js

@@ -583,9 +583,9 @@ Batch.prototype.write = function write(callback) {
   });
 
   this.ops.length = 0;
-  delete this.ops;
-  delete this.options;
-  delete this.tree;
+  this.ops = null;
+  this.options = null;
+  this.tree = null;
 
   utils.nextTick(callback);
 
@@ -691,9 +691,9 @@ Iterator.prototype._end = function end() {
   if (!this.tree)
     return;
 
-  delete this.tree;
+  this.tree = null;
   this.items.length = 0;
-  delete this.items;
+  this.items = null;
 };
 
 Iterator.prototype.end = function end(callback) {

lib/bcoin/memblock.js

@@ -100,7 +100,7 @@ MemBlock.prototype.getCoinbaseHeight = function getCoinbaseHeight() {
 
 MemBlock.prototype.toBlock = function toBlock() {
   var data = bcoin.protocol.parser.parseBlock(this.raw);
-  delete this.raw;
+  this.raw = null;
   return new bcoin.block(data);
 };
 

lib/bcoin/pool.js

@@ -133,6 +133,8 @@ function Pool(options) {
   this.synced = false;
   this._scheduled = false;
   this._pendingWatch = null;
+  this._timer = null;
+  this._interval = null;
 
   this.load = {
     timeout: options.loadTimeout || 120000,
@@ -436,11 +438,11 @@ Pool.prototype._startTimer = function _startTimer() {
 };
 
 Pool.prototype._stopTimer = function _stopTimer() {
-  if (!this._timer)
+  if (this._timer == null)
     return;
 
   clearTimeout(this._timer);
-  delete this._timer;
+  this._timer = null;
 };
 
 Pool.prototype._startInterval = function _startInterval() {
@@ -466,11 +468,11 @@ Pool.prototype._startInterval = function _startInterval() {
 };
 
 Pool.prototype._stopInterval = function _stopInterval() {
-  if (!this._interval)
+  if (this._interval == null)
     return;
 
   clearInterval(this._interval);
-  delete this._interval;
+  this._interval = null;
 };
 
 Pool.prototype._addLoader = function _addLoader() {

lib/bcoin/reader.js

@@ -128,9 +128,9 @@ BufferReader.prototype.endData = function endData(zeroCopy) {
  */
 
 BufferReader.prototype.destroy = function destroy() {
-  delete this.offset;
-  delete this.stack;
-  delete this.data;
+  this.offset = null;
+  this.stack = null;
+  this.data = null;
 };
 
 /**

lib/bcoin/script.js

@@ -1974,7 +1974,7 @@ Script.prototype.removeData = function removeData(data) {
     this.code.splice(index[i], 1);
 
   if (this.raw) {
-    delete this.raw;
+    this.raw = null;
     this.encode();
   }
 

lib/bcoin/writer.js

@@ -148,8 +148,8 @@ BufferWriter.prototype.seek = function seek(offset) {
 
 BufferWriter.prototype.destroy = function destroy() {
   this.data.length = 0;
-  delete this.data;
-  delete this.written;
+  this.data = null;
+  this.written = null;
 };
 
 /**