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

Author: https://github.com/kennethmyhra
Commit: https://github.com/SerenityOS/serenity/commit/29521b50e6
Pull-request: https://github.com/SerenityOS/serenity/pull/23874
Reviewed-by: https://github.com/shannonbooth ✅

Tests/LibWeb/Text/expected/Streams/ReadableStream-pipeThrough-cannot-pipe-locked-stream.txt

@@ -0,0 +1 @@
+TypeError: Failed to execute 'pipeThrough' on 'ReadableStream': Cannot pipe a locked stream

Tests/LibWeb/Text/expected/Streams/ReadableStream-pipeThrough-cannot-pipe-to-locked-stream.txt

@@ -0,0 +1 @@
+TypeError: Failed to execute 'pipeThrough' on 'ReadableStream': parameter 1's 'writable' is locked

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

@@ -0,0 +1,17 @@
+<script src="../include.js"></script>
+<script>
+    asyncTest(done => {
+        const transformStream = new TransformStream();
+
+        const stream = new ReadableStream();
+
+        stream.getReader();
+        try {
+            stream.pipeThrough(transformStream);
+        }
+        catch (e) {
+            println(e);
+        }
+        done();
+    });
+</script>

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

@@ -0,0 +1,17 @@
+<script src="../include.js"></script>
+<script>
+    asyncTest(done => {
+        const transformStream = new TransformStream();
+
+        const stream = new ReadableStream();
+
+        transformStream.writable.getWriter();
+        try {
+            stream.pipeThrough(transformStream);
+        }
+        catch (e) {
+            println(e);
+        }
+        done();
+    });
+</script>