stream: readable cosmetics

Author: ronag

lib/_stream_readable.js

@@ -192,10 +192,7 @@ Object.defineProperty(Readable.prototype, 'destroyed', {
   // userland will fail
   enumerable: false,
   get() {
-    if (this._readableState === undefined) {
-      return false;
-    }
-    return this._readableState.destroyed;
+    return this._readableState ? this._readableState.destroyed : false;
   },
   set(value) {
     // We ignore the value if the stream
@@ -266,7 +263,7 @@ function readableAddChunk(stream, chunk, encoding, addToFront) {
     state.reading = false;
     onEofChunk(stream, state);
   } else {
-    var er;
+    let er;
     if (!skipChunkCheck)
       er = chunkInvalid(state, chunk);
     if (er) {
@@ -354,14 +351,16 @@ Readable.prototype.isPaused = function() {
 
 // Backwards compatibility.
 Readable.prototype.setEncoding = function(enc) {
+  const state = this._readableState;
+
   if (!StringDecoder)
     StringDecoder = require('string_decoder').StringDecoder;
   const decoder = new StringDecoder(enc);
-  this._readableState.decoder = decoder;
+  state.decoder = decoder;
   // If setEncoding(null), decoder.encoding equals utf8
-  this._readableState.encoding = this._readableState.decoder.encoding;
+  state.encoding = state.decoder.encoding;
 
-  const buffer = this._readableState.buffer;
+  const buffer = state.buffer;
   // Iterate over current buffer to convert already stored Buffers:
   let content = '';
   for (const data of buffer) {
@@ -370,7 +369,7 @@ Readable.prototype.setEncoding = function(enc) {
   buffer.clear();
   if (content !== '')
     buffer.push(content);
-  this._readableState.length = content.length;
+  state.length = content.length;
   return this;
 };
 
@@ -481,7 +480,7 @@ Readable.prototype.read = function(n) {
   // 3. Actually pull the requested chunks out of the buffer and return.
 
   // if we need a readable event, then we need to do some reading.
-  var doRead = state.needReadable;
+  let doRead = state.needReadable;
   debug('need readable', doRead);
 
   // If we currently have less than the highWaterMark, then also read some
@@ -511,7 +510,7 @@ Readable.prototype.read = function(n) {
       n = howMuchToRead(nOrig, state);
   }
 
-  var ret;
+  let ret;
   if (n > 0)
     ret = fromList(n, state);
   else
@@ -550,7 +549,7 @@ function onEofChunk(stream, state) {
   debug('onEofChunk');
   if (state.ended) return;
   if (state.decoder) {
-    var chunk = state.decoder.end();
+    const chunk = state.decoder.end();
     if (chunk && chunk.length) {
       state.buffer.push(chunk);
       state.length += state.objectMode ? 1 : chunk.length;
@@ -711,7 +710,7 @@ Readable.prototype.pipe = function(dest, pipeOpts) {
 
   let ondrain;
 
-  var cleanedUp = false;
+  let cleanedUp = false;
   function cleanup() {
     debug('cleanup');
     // Cleanup event handlers once the pipe is broken
@@ -847,11 +846,11 @@ Readable.prototype.unpipe = function(dest) {
 
   if (!dest) {
     // remove all.
-    var dests = state.pipes;
+    const dests = state.pipes;
     state.pipes = [];
     state.flowing = false;
 
-    for (var i = 0; i < dests.length; i++)
+    for (let i = 0; i < dests.length; i++)
       dests[i].emit('unpipe', this, { hasUnpiped: false });
     return this;
   }
@@ -1012,12 +1011,12 @@ function flow(stream) {
 // It is an ugly unfortunate mess of history.
 Readable.prototype.wrap = function(stream) {
   const state = this._readableState;
-  var paused = false;
+  let paused = false;
 
   stream.on('end', () => {
     debug('wrapped end');
     if (state.decoder && !state.ended) {
-      var chunk = state.decoder.end();
+      const chunk = state.decoder.end();
       if (chunk && chunk.length)
         this.push(chunk);
     }
@@ -1055,7 +1054,7 @@ Readable.prototype.wrap = function(stream) {
   }
 
   // Proxy certain important events.
-  for (var n = 0; n < kProxyEvents.length; n++) {
+  for (let n = 0; n < kProxyEvents.length; n++) {
     stream.on(kProxyEvents[n], this.emit.bind(this, kProxyEvents[n]));
   }
 
@@ -1151,7 +1150,7 @@ function fromList(n, state) {
   if (state.length === 0)
     return null;
 
-  var ret;
+  let ret;
   if (state.objectMode)
     ret = state.buffer.shift();
   else if (!n || n >= state.length) {