doc: clarify pipeline stream cleanup

doc/api/stream.md

@@ -1590,6 +1590,12 @@ async function run() {
 run().catch(console.error);
 ```
 
+On completion or error `stream.pipeline()` will call `stream.destroy(err)` on
+all provided stream except for `Readable` streams which have emitted `'end'`
+or `'close'` and `Writable` streams which have emitted `'finish'` or `'close'`.
+Unless `autoDestroy` is enabled these streams will not be automatically cleaned
+up.
+
 `stream.pipeline()` leaves dangling event listeners on the streams
 after the `callback` has been invoked. In the case of reuse of streams after
 failure, this can cause event listener leaks and swallowed errors.

test.js

@@ -0,0 +1,9 @@
+const { Readable } = require('stream')
+
+const r = new Readable();
+
+readable.on('readable', function() {
+  while (data = this.read()) {
+    console.log(data);
+  }
+});