stream: fix readable stream as async iterator function

ErickWendel · juanarbol · commit 3acfe9bf926a · 2023-03-04T23:03:28.000-05:00
Since v19.2 it's not possible to use readableStreams as async iterators (confirmed bug). This patch fixes the problem by reading the Stream.Duplex property from 'streams/duplex' instead of 'streams/legacy' module Fixes: #46141 PR-URL: #46147 Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com> Reviewed-By: Robert Nagy <ronagy@icloud.com> Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
diff --git a/lib/stream/promises.js b/lib/stream/promises.js
@@ -13,6 +13,8 @@ const {
 const { pipelineImpl: pl } = require('internal/streams/pipeline');
 const { finished } = require('internal/streams/end-of-stream');
 
+require('stream');
+
 function pipeline(...streams) {
   return new Promise((resolve, reject) => {
     let signal;
diff --git a/test/parallel/test-stream3-pipeline-async-iterator.js b/test/parallel/test-stream3-pipeline-async-iterator.js
@@ -0,0 +1,27 @@
+/* eslint-disable node-core/require-common-first, require-yield */
+'use strict';
+const { pipeline } = require('node:stream/promises');
+{
+  // Ensure that async iterators can act as readable and writable streams
+  async function* myCustomReadable() {
+    yield 'Hello';
+    yield 'World';
+  }
+
+  const messages = [];
+  async function* myCustomWritable(stream) {
+    for await (const chunk of stream) {
+      messages.push(chunk);
+    }
+  }
+
+  (async () => {
+    await pipeline(
+      myCustomReadable,
+      myCustomWritable,
+    );
+    // Importing here to avoid initializing streams
+    require('assert').deepStrictEqual(messages, ['Hello', 'World']);
+  })()
+  .then(require('../common').mustCall());
+}
