ladybird/Tests/LibWeb/Text/input/Streams/TransformStream-flush-callback.html

<script src="../include.js"></script>
<script>
  test(() => {
    const {writable, readable} = new TransformStream({
      transform(chunk, controller) {
        controller.enqueue(chunk.toUpperCase());
      },
      flush(controller) {
          controller.enqueue("Enqueued in flush, this the last chunk that will be processed.");
      }
    });
    const writer = writable.getWriter();
    writer.write("Hello, world!");
    writer.close();
    const reader = readable.getReader();
    reader.read().then(function processText({done, value}) {
      println(`Done: ${done}`);
      if (done)
        return;

      println(value);
      reader.read().then(processText);
    });
  });
</script>