test: add known issue test for sync writable callback

jasnell · codebytere · commit 60c71dcad21a · 2020-02-27T08:47:15.000-08:00
If the write callbacks are invoked synchronously with an error, onwriteError would cause the error event to be emitted synchronously, making it impossible to attach an error handler after the call that triggered it. PR-URL: #31756 Refs: nodejs/quic@b0d469c Refs: nodejs/quic#341 Reviewed-By: Robert Nagy <ronagy@icloud.com> Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Minwoo Jung <nodecorelab@gmail.com>
diff --git a/test/known_issues/test-stream-writable-sync-error.js b/test/known_issues/test-stream-writable-sync-error.js
@@ -0,0 +1,44 @@
+'use strict';
+const common = require('../common');
+
+// Tests for the regression in _stream_writable discussed in
+// https://github.com/nodejs/node/pull/31756
+
+// Specifically, when a write callback is invoked synchronously
+// with an error, and autoDestroy is not being used, the error
+// should still be emitted on nextTick.
+
+const { Writable } = require('stream');
+
+class MyStream extends Writable {
+  #cb = undefined;
+
+  constructor() {
+    super({ autoDestroy: false });
+  }
+
+  _write(_, __, cb) {
+    this.#cb = cb;
+  }
+
+  close() {
+    // Synchronously invoke the callback with an error.
+    this.#cb(new Error('foo'));
+  }
+}
+
+const stream = new MyStream();
+
+const mustError = common.mustCall(2);
+
+stream.write('test', () => {});
+
+// Both error callbacks should be invoked.
+
+stream.on('error', mustError);
+
+stream.close();
+
+// Without the fix in #31756, the error handler
+// added after the call to close will not be invoked.
+stream.on('error', mustError);
