WritableStreamDefaultWriter: closed property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since May 2022.

Note: This feature is available in Web Workers.

The closed read-only property of the WritableStreamDefaultWriter interface returns a Promise that fulfills if the stream becomes closed, or rejects if the stream errors or the writer's lock is released.

Value

A Promise.

Examples

js
const writableStream = new WritableStream(
  {
    start(controller) {},
    write(chunk, controller) {
      // …
    },
    close(controller) {
      // …
    },
    abort(err) {
      // …
    },
  },
  queuingStrategy,
);

// …

const writer = writableStream.getWriter();

// ..

// check if the stream is closed
writer.closed.then(() => {
  console.log("writer closed");
});

Specifications

Specification
Streams
# ref-for-default-writer-closed②

Browser compatibility