stream: ended streams should resolve the async iteration

Fixes: https://github.com/nodejs/node/issues/23891

PR-URL: https://github.com/nodejs/node/pull/23901
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/internal/streams/async_iterator.js

@@ -127,7 +127,10 @@ const createReadableStreamAsyncIterator = (stream) => {
     [kLastResolve]: { value: null, writable: true },
     [kLastReject]: { value: null, writable: true },
     [kError]: { value: null, writable: true },
-    [kEnded]: { value: false, writable: true },
+    [kEnded]: {
+      value: stream._readableState.endEmitted,
+      writable: true
+    },
     [kLastPromise]: { value: null, writable: true },
     // the function passed to new Promise
     // is cached so we avoid allocating a new

test/parallel/test-stream-readable-async-iterators.js

@@ -362,6 +362,24 @@ async function tests() {
       assert.strictEqual(e, err);
     }
   })();
+
+  await (async () => {
+    console.log('iterating on an ended stream completes');
+    const r = new Readable({
+      objectMode: true,
+      read() {
+        this.push('asdf');
+        this.push('hehe');
+        this.push(null);
+      }
+    });
+    // eslint-disable-next-line no-unused-vars
+    for await (const a of r) {
+    }
+    // eslint-disable-next-line no-unused-vars
+    for await (const b of r) {
+    }
+  })();
 }
 
 // to avoid missing some tests if a promise does not resolve