doc: fix stream async iterator sample

The for await loop into writable loop could cause an unhandled exception in the case where we are waiting for data from the async iterable and this no `'error'` handler is registered on the writable. Fixes: #31222 PR-URL: #31252 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Rich Trott <[email protected]> Reviewed-By: James M Snell <[email protected]>
nodejs · Mar 17, 2020 · 4922184 · 4922184
1 parent 623e111
commit 4922184
Showing 1 changed file with 11 additions and 3 deletions.
diff --git a/doc/api/stream.md b/doc/api/stream.md
@@ -2639,15 +2639,23 @@ const finished = util.promisify(stream.finished);
 
 const writable = fs.createWriteStream('./file');
 
-(async function() {
+async function pump(iterator, writable) {
   for await (const chunk of iterator) {
     // Handle backpressure on write().
-    if (!writable.write(chunk))
+    if (!writable.write(chunk)) {
+      if (writable.destroyed) return;
       await once(writable, 'drain');
+    }
   }
   writable.end();
+}
+
+(async function() {
   // Ensure completion without errors.
-  await finished(writable);
+  await Promise.all([
+    pump(iterator, writable),
+    finished(writable)
+  ]);
 })();
 ```