stream: allow returning null from pipeline tail

ronag · sxa · commit 53338fe65cd6 · 2022-03-07T17:34:28.000Z
PR-URL: #42078 Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
diff --git a/lib/internal/streams/pipeline.js b/lib/internal/streams/pipeline.js
@@ -265,7 +265,9 @@ function pipelineImpl(streams, callback, opts) {
 then.call(ret,
 (val) => {
 value = val;
- pt.write(val);
+ if (val != null) {
+ pt.write(val);
+ }
 if (end) {
 pt.end();
 }
diff --git a/test/parallel/test-stream-pipeline.js b/test/parallel/test-stream-pipeline.js
@@ -1511,3 +1511,18 @@ const tsp = require('timers/promises');
 assert.strictEqual(s.destroyed, true);
 }));
 }
+
+{
+ const s = new PassThrough({ objectMode: true });
+ pipeline(async function*() {
+ await Promise.resolve();
+ yield 'hello';
+ yield 'world';
+ yield 'world';
+ }, s, async function(source) {
+ return null;
+ }, common.mustCall((err, val) => {
+ assert.strictEqual(err, undefined);
+ assert.strictEqual(val, null);
+ }));
+}

-Original file line number
+Diff line change
 then.call(ret,
 (val)=>{
 value=val;
 -pt.write(val);
 +if(val!=null){
 +pt.write(val);
 +}
 if(end){
 pt.end();
+}
-Original file line number
+Diff line change
 assert.strictEqual(s.destroyed,true);
 }));
+}
++
 +{
 +consts=newPassThrough({objectMode: true});
 +pipeline(asyncfunction*(){
 +awaitPromise.resolve();
 +yield'hello';
 +yield'world';
 +yield'world';
 +},s,asyncfunction(source){
 +returnnull;
 +},common.mustCall((err,val)=>{
 +assert.strictEqual(err,undefined);
 +assert.strictEqual(val,null);
 +}));
 +}