lib,src,test: fix comments

lib/_stream_readable.js

@@ -834,7 +834,7 @@ Readable.prototype.removeListener = function(ev, fn) {
 
   if (ev === 'readable') {
     // We need to check if there is someone still listening to
-    // to readable and reset the state. However this needs to happen
+    // readable and reset the state. However this needs to happen
     // after readable has been emitted but before I/O (nextTick) to
     // support once('readable', fn) cycles. This means that calling
     // resume within the same tick will have no
@@ -850,7 +850,7 @@ Readable.prototype.removeAllListeners = function(ev) {
 
   if (ev === 'readable' || ev === undefined) {
     // We need to check if there is someone still listening to
-    // to readable and reset the state. However this needs to happen
+    // readable and reset the state. However this needs to happen
     // after readable has been emitted but before I/O (nextTick) to
     // support once('readable', fn) cycles. This means that calling
     // resume within the same tick will have no

src/node.cc

@@ -2675,7 +2675,7 @@ static void EnvGetter(Local<Name> property,
                                          arraysize(buffer));
   // If result >= sizeof buffer the buffer was too small. That should never
   // happen. If result == 0 and result != ERROR_SUCCESS the variable was not
-  // not found.
+  // found.
   if ((result > 0 || GetLastError() == ERROR_SUCCESS) &&
       result < arraysize(buffer)) {
     const uint16_t* two_byte_buffer = reinterpret_cast<const uint16_t*>(buffer);

src/stream_base-inl.h

@@ -70,7 +70,7 @@ inline StreamResource::~StreamResource() {
     StreamListener* listener = listener_;
     listener->OnStreamDestroy();
     // Remove the listener if it didn’t remove itself. This makes the logic
-    // logic in `OnStreamDestroy()` implementations easier, because they
+    // in `OnStreamDestroy()` implementations easier, because they
     // may call generic cleanup functions which can just remove the
     // listener unconditionally.
     if (listener == listener_)

src/tracing/node_trace_buffer.cc

@@ -134,7 +134,7 @@ bool NodeTraceBuffer::Flush() {
 }
 
 // Attempts to set current_buf_ such that it references a buffer that can
-// can write at least one trace event. If both buffers are unavailable this
+// write at least one trace event. If both buffers are unavailable this
 // method returns false; otherwise it returns true.
 bool NodeTraceBuffer::TryLoadAvailableBuffer() {
   InternalTraceBuffer* prev_buf = current_buf_.load();

src/tracing/node_trace_writer.cc

@@ -153,7 +153,7 @@ void NodeTraceWriter::WriteToFile(std::string&& str, int highest_request_id) {
       write_req->str.length());
   request_mutex_.Lock();
   // Manage a queue of WriteRequest objects because the behavior of uv_write is
-  // is undefined if the same WriteRequest object is used more than once
+  // undefined if the same WriteRequest object is used more than once
   // between WriteCb calls. In addition, this allows us to keep track of the id
   // of the latest write request that actually been completed.
   write_req_queue_.push(write_req);

test/sequential/test-timers-blocking-callback.js

@@ -3,7 +3,7 @@
 /*
  * This is a regression test for
  * https://github.com/nodejs/node-v0.x-archive/issues/15447 and
- * and https://github.com/nodejs/node-v0.x-archive/issues/9333.
+ * https://github.com/nodejs/node-v0.x-archive/issues/9333.
  *
  * When a timer is added in another timer's callback, its underlying timer
  * handle was started with a timeout that was actually incorrect.