1 files changed, 10 insertions, 12 deletions

diff --git a/lib/_stream_readable.js b/lib/_stream_readable.js
index c6f31bc1f9..0b5af41f1c 100644
--- a/lib/_stream_readable.js
+++ b/lib/_stream_readable.js
@@ -117,7 +117,7 @@ function Readable(options) {
 Readable.prototype.push = function(chunk, encoding) {
   var state = this._readableState;
 
-  if (typeof chunk === 'string' && !state.objectMode) {
+  if (IS_STRING(chunk) && !state.objectMode) {
     encoding = encoding || state.defaultEncoding;
     if (encoding !== state.encoding) {
       chunk = new Buffer(chunk, encoding);
@@ -138,7 +138,7 @@ function readableAddChunk(stream, state, chunk, encoding, addToFront) {
   var er = chunkInvalid(state, chunk);
   if (er) {
     stream.emit('error', er);
-  } else if (chunk === null || chunk === undefined) {
+  } else if (IS_NULL_OR_UNDEFINED(chunk)) {
     state.reading = false;
     if (!state.ended)
       onEofChunk(stream, state);
@@ -219,7 +219,7 @@ function howMuchToRead(n, state) {
   if (state.objectMode)
     return n === 0 ? 0 : 1;
 
-  if (isNaN(n) || n === null) {
+  if (isNaN(n) || IS_NULL(n)) {
     // only flow one buffer at a time
     if (state.flowing && state.buffer.length)
       return state.buffer[0].length;
@@ -256,7 +256,7 @@ Readable.prototype.read = function(n) {
   state.calledRead = true;
   var nOrig = n;
 
-  if (typeof n !== 'number' || n > 0)
+  if (!IS_NUMBER(n) || n > 0)
     state.emittedReadable = false;
 
   // if we're doing read(0) to trigger a readable event, but we
@@ -345,7 +345,7 @@ Readable.prototype.read = function(n) {
   else
     ret = null;
 
-  if (ret === null) {
+  if (IS_NULL(ret)) {
     state.needReadable = true;
     n = 0;
   }
@@ -363,17 +363,16 @@ Readable.prototype.read = function(n) {
   if (state.ended && !state.endEmitted && state.length === 0)
     endReadable(this);
 
-  if (ret !== null)
+  if (!IS_NULL(ret))
     this.emit('data', ret);
   return ret;
 };
 
 function chunkInvalid(state, chunk) {
   var er = null;
-  if (!Buffer.isBuffer(chunk) &&
-      'string' !== typeof chunk &&
-      chunk !== null &&
-      chunk !== undefined &&
+  if (!IS_BUFFER(chunk) &&
+      !IS_STRING(chunk) &&
+      !IS_NULL_OR_UNDEFINED(chunk) &&
       !state.objectMode &&
       !er) {
     er = new TypeError('Invalid non-string/buffer chunk');
@@ -775,8 +774,7 @@ Readable.prototype.wrap = function(stream) {
   // proxy all the other methods.
   // important when wrapping filters and duplexes.
   for (var i in stream) {
-    if (typeof stream[i] === 'function' &&
-        typeof this[i] === 'undefined') {
+    if (IS_FUNCTION(stream[i]) && IS_UNDEFINED(this[i])) {
       this[i] = function(method) { return function() {
         return stream[method].apply(stream, arguments);
       }}(i);