diff --git a/lib/_stream_readable.js b/lib/_stream_readable.js index 81e8de310c240f..6198da5ca6be76 100644 --- a/lib/_stream_readable.js +++ b/lib/_stream_readable.js @@ -475,7 +475,7 @@ Readable.prototype.read = function(n) { ret = null; if (ret === null) { - state.needReadable = true; + state.needReadable = state.length <= state.highWaterMark; n = 0; } else { state.length -= n; diff --git a/test/parallel/test-stream-readable-resume-hwm.js b/test/parallel/test-stream-readable-resume-hwm.js new file mode 100644 index 00000000000000..3f0bbad243b0a2 --- /dev/null +++ b/test/parallel/test-stream-readable-resume-hwm.js @@ -0,0 +1,21 @@ +'use strict'; +const common = require('../common'); +const { Readable } = require('stream'); + +// readable.resume() should not lead to a ._read() call being scheduled +// when we exceed the high water mark already. + +const readable = new Readable({ + read: common.mustNotCall(), + highWaterMark: 100 +}); + +// Fill up the internal buffer so that we definitely exceed the HWM: +for (let i = 0; i < 10; i++) + readable.push('a'.repeat(200)); + +// Call resume, and pause after one chunk. +// The .pause() is just so that we don’t empty the buffer fully, which would +// be a valid reason to call ._read(). +readable.resume(); +readable.once('data', common.mustCall(() => readable.pause()));