stream: test that multiple streams can be unpiped in the reverse orde…

…r from which they were piped

test/parallel/test-stream-unpipe-multiple-pipes.js

@@ -0,0 +1,17 @@
+'use strict';
+const common = require('../common');
+const stream = require('stream');
+
+const source = stream.Readable({read: () => {}});
+const dest1 = stream.Writable({write: () => {}});
+const dest2 = stream.Writable({write: () => {}});
+
+source.pipe(dest1);
+source.pipe(dest2);
+
+dest1.on('unpipe', common.mustCall(() => {}));
+dest2.on('unpipe', common.mustCall(() => {}));
+
+//should be able to unpipe them in the reverse order that they were piped
+source.unpipe(dest2);
+source.unpipe(dest1);