WHATWG Streams

const stream = new ReadableStream({
  start(controller) {
    controller.enqueue("hello");
    controller.enqueue("world");
    controller.close();
  },
});

const reader = stream.getReader();
(await reader.read()).value; // "hello"
(await reader.read()).value; // "world"
(await reader.read()).done;  // true

const upper = new TransformStream({
  transform(chunk, controller) {
    controller.enqueue(chunk.toUpperCase());
  },
});

const source = ReadableStream.from(["hello"]);
const destination = new WritableStream({
  write(chunk) {
    console.log(chunk); // HELLO
  },
});

await source.pipeThrough(upper).pipeTo(destination);

const bytes = new ReadableStream({
  type: "bytes",
  start(controller) {
    controller.enqueue(new Uint8Array([1, 2, 3]));
    controller.close();
  },
});

const reader = bytes.getReader({ mode: "byob" });
const target = new Uint8Array(8);
const pending = reader.read(target);
target.buffer.byteLength; // 0: transferred immediately

const { value } = await pending;
Array.from(value); // [1, 2, 3]