stream: fix disparity between buffer and the count

lib/_stream_writable.js

@@ -502,6 +502,7 @@ function clearBuffer(stream, state) {
  corkReq.finish = onCorkedFinish.bind(undefined, corkReq, state);
  state.corkedRequestsFree = corkReq;
  }
+ state.bufferedRequestCount = 0;
  } else {
  // Slow case, write chunks one-by-one
  while (entry) {
@@ -512,6 +513,7 @@ function clearBuffer(stream, state) {
 
  doWrite(stream, state, false, len, chunk, encoding, cb);
  entry = entry.next;
+ state.bufferedRequestCount--;
  // if we didn't call the onwrite immediately, then
  // it means that we need to wait until it does.
  // also, that means that the chunk and cb are currently
@@ -525,7 +527,6 @@ function clearBuffer(stream, state) {
  state.lastBufferedRequest = null;
  }
 
- state.bufferedRequestCount = 0;
  state.bufferedRequest = entry;
  state.bufferProcessing = false;
 }

test/sequential/test-stream-writable-clear-buffer.js

@@ -0,0 +1,34 @@
+'use strict';
+const common = require('../common');
+const Stream = require('stream');
+// This test ensures that the _writeableState.bufferedRequestCount and
+// the actual buffered request count are the same
+const assert = require('assert');
+
+class StreamWritable extends Stream.Writable {
+ constructor() {
+ super({ objectMode: true });
+ }
+
+ // We need a timeout like on the original issue thread
+ // otherwise the code will never reach our test case
+ // this means this should go on the sequential folder.
+ _write(chunk, encoding, cb) {
+ setTimeout(cb, common.platformTimeout(10));
+ }
+}
+
+const testStream = new StreamWritable();
+testStream.cork();
+
+for (let i = 1; i <= 5; i++) {
+ testStream.write(i, function() {
+ assert.strictEqual(
+ testStream._writableState.bufferedRequestCount,
+ testStream._writableState.getBuffer().length,
+ 'bufferedRequestCount variable is different from the actual length of' +
+ ' the buffer');
+ });
+}
+
+testStream.end();