From 80158ecb60e437880338491d6cd59aa720235c6f Mon Sep 17 00:00:00 2001
From: David Mark Clements <huperekchuno@googlemail.com>
Date: Fri, 5 Jul 2019 20:02:08 +0200
Subject: [PATCH 1/3] stream: null push transform in async_iterator

when the readable side of a transform ends any for await
loop on that transform stream should also complete. This
fix prevents for await loop on a transform stream
from hanging indefinitely.

https://github.com/nodejs/node/pull/28566
---
 lib/internal/streams/async_iterator.js        |  2 +-
 .../test-stream-readable-async-iterators.js   | 24 ++++++++++++++++++-
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/lib/internal/streams/async_iterator.js b/lib/internal/streams/async_iterator.js
index defba235adbd56..89a1dae7fdfb02 100644
--- a/lib/internal/streams/async_iterator.js
+++ b/lib/internal/streams/async_iterator.js
@@ -155,7 +155,7 @@ const createReadableStreamAsyncIterator = (stream) => {
   });
   iterator[kLastPromise] = null;
 
-  finished(stream, (err) => {
+  finished(stream, { writable: false }, (err) => {
     if (err && err.code !== 'ERR_STREAM_PREMATURE_CLOSE') {
       const reject = iterator[kLastReject];
       // Reject if we are waiting for data in the Promise returned by next() and
diff --git a/test/parallel/test-stream-readable-async-iterators.js b/test/parallel/test-stream-readable-async-iterators.js
index b50a6b1734b32b..0fc701e82ed929 100644
--- a/test/parallel/test-stream-readable-async-iterators.js
+++ b/test/parallel/test-stream-readable-async-iterators.js
@@ -1,7 +1,7 @@
 'use strict';
 
 const common = require('../common');
-const { Readable, PassThrough, pipeline } = require('stream');
+const { Readable, Transform, PassThrough, pipeline } = require('stream');
 const assert = require('assert');
 
 async function tests() {
@@ -396,6 +396,28 @@ async function tests() {
     }
   }
 
+  console.log('readable side of a transform stream pushes null');
+  {
+    const transform = new Transform({
+      objectMode: true,
+      transform(chunk, enc, cb) {
+        cb(null, chunk);
+      }
+    });
+    transform.push(0);
+    transform.push(1);
+    transform.push(null);
+    const mustReach = common.mustCall();
+    const iter = transform[Symbol.asyncIterator]();
+    assert.strictEqual((await iter.next()).value, 0);
+
+    for await (const d of iter) {
+      assert.strictEqual(d, 1);
+    }
+
+    mustReach();
+  }
+
   {
     console.log('all next promises must be resolved on end');
     const r = new Readable({

From aa9de1d6e47d43abf9d21936031c7f95e3049abc Mon Sep 17 00:00:00 2001
From: David Mark Clements <huperekchuno@googlemail.com>
Date: Sun, 7 Jul 2019 21:41:00 +0200
Subject: [PATCH 2/3] tests: clarify transform async iterator test

---
 test/parallel/test-stream-readable-async-iterators.js | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/test/parallel/test-stream-readable-async-iterators.js b/test/parallel/test-stream-readable-async-iterators.js
index 0fc701e82ed929..5c77181e68e31b 100644
--- a/test/parallel/test-stream-readable-async-iterators.js
+++ b/test/parallel/test-stream-readable-async-iterators.js
@@ -400,9 +400,7 @@ async function tests() {
   {
     const transform = new Transform({
       objectMode: true,
-      transform(chunk, enc, cb) {
-        cb(null, chunk);
-      }
+      transform: common.mustNotCall()
     });
     transform.push(0);
     transform.push(1);

From 6382470b37dcf1eb5c657ad65a253a28fd3cb6b1 Mon Sep 17 00:00:00 2001
From: David Mark Clements <huperekchuno@googlemail.com>
Date: Fri, 12 Jul 2019 14:46:29 +0200
Subject: [PATCH 3/3] tests: fix transform async iterator test

---
 .../test-stream-readable-async-iterators.js      | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/test/parallel/test-stream-readable-async-iterators.js b/test/parallel/test-stream-readable-async-iterators.js
index 5c77181e68e31b..12971cb2363a80 100644
--- a/test/parallel/test-stream-readable-async-iterators.js
+++ b/test/parallel/test-stream-readable-async-iterators.js
@@ -396,24 +396,28 @@ async function tests() {
     }
   }
 
-  console.log('readable side of a transform stream pushes null');
   {
+    console.log('readable side of a transform stream pushes null');
     const transform = new Transform({
       objectMode: true,
-      transform: common.mustNotCall()
+      transform: (chunk, enc, cb) => { cb(null, chunk); }
     });
     transform.push(0);
     transform.push(1);
-    transform.push(null);
-    const mustReach = common.mustCall();
+    process.nextTick(() => {
+      transform.push(null);
+    });
+
+    const mustReach = [ common.mustCall(), common.mustCall() ];
+
     const iter = transform[Symbol.asyncIterator]();
     assert.strictEqual((await iter.next()).value, 0);
 
     for await (const d of iter) {
       assert.strictEqual(d, 1);
+      mustReach[0]();
     }
-
-    mustReach();
+    mustReach[1]();
   }
 
   {