1234567891011121314151617181920212223242526272829303132333435363738394041
// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
/** * Merge multiple streams into a single one, not taking order into account. * If a stream ends before other ones, the other will continue adding data, * and the finished one will not add any more data. */export function mergeReadableStreams<T>(  ...streams: ReadableStream<T>[]): ReadableStream<T> {  const resolvePromises = streams.map(() => Promise.withResolvers<void>());  return new ReadableStream<T>({    start(controller) {      let mustClose = false;      Promise.all(resolvePromises.map(({ promise }) => promise))        .then(() => {          controller.close();        })        .catch((error) => {          mustClose = true;          controller.error(error);        });      for (const [index, stream] of streams.entries()) {        (async () => {          try {            for await (const data of stream) {              if (mustClose) {                break;              }              controller.enqueue(data);            }            resolvePromises[index].resolve();          } catch (error) {            resolvePromises[index].reject(error);          }        })();      }    },  });}