Tests/LibWeb: Verify we throw when trying to pipe from/to locked streams

Author: https://github.com/kennethmyhra
Commit: https://github.com/SerenityOS/serenity/commit/a0802b6e29
Pull-request: https://github.com/SerenityOS/serenity/pull/23869
Reviewed-by: https://github.com/shannonbooth ✅

Tests/LibWeb/Text/input/Streams/ReadableStream-pipeTo-cannot-pipe-locked-stream.html

@@ -0,0 +1,22 @@
+<script src="../include.js"></script>
+<script>
+    asyncTest(done => {
+        const writableStream = new WritableStream(
+            {
+                write(chunk) {}
+            }
+        );
+        const stream = new ReadableStream({
+            start(controller) {},
+            pull(controller) {},
+            cancel() {},
+        });
+
+        stream.getReader();
+        stream.pipeTo(writableStream)
+            .catch(reason => {
+                println(reason);
+                done();
+            });
+    });
+</script>