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Node.js module

stream/consumers

The 'node:stream/consumers' submodule offers helper functions that consume Readable streams into other forms, such as blob, arrayBuffer, text, or json.

It simplifies common stream-to-data conversions without manual event handling.

  • function arrayBuffer(
    stream: ReadableStream | AsyncIterable<any, any, any> | ReadableStream<any>
    ): Promise<ArrayBuffer>;
    import { arrayBuffer } from 'node:stream/consumers';
import { Readable } from 'node:stream';
import { TextEncoder } from 'node:util';

const encoder = new TextEncoder();
const dataArray = encoder.encode('hello world from consumers!');

const readable = Readable.from(dataArray);
const data = await arrayBuffer(readable);
console.log(`from readable: ${data.byteLength}`);
// Prints: from readable: 76
    @returns

    Fulfills with an ArrayBuffer containing the full contents of the stream.

  • function blob(
    stream: ReadableStream | AsyncIterable<any, any, any> | ReadableStream<any>
    ): Promise<Blob>;
    import { blob } from 'node:stream/consumers';

const dataBlob = new Blob(['hello world from consumers!']);

const readable = dataBlob.stream();
const data = await blob(readable);
console.log(`from readable: ${data.size}`);
// Prints: from readable: 27
    @returns

    Fulfills with a Blob containing the full contents of the stream.

  • function buffer(
    stream: ReadableStream | AsyncIterable<any, any, any> | ReadableStream<any>
    ): Promise<NonSharedBuffer>;
    import { buffer } from 'node:stream/consumers';
import { Readable } from 'node:stream';
import { Buffer } from 'node:buffer';

const dataBuffer = Buffer.from('hello world from consumers!');

const readable = Readable.from(dataBuffer);
const data = await buffer(readable);
console.log(`from readable: ${data.length}`);
// Prints: from readable: 27
    @returns

    Fulfills with a Buffer containing the full contents of the stream.

  • function bytes(
    stream: ReadableStream | AsyncIterable<any, any, any> | ReadableStream<any>
    ): Promise<NonSharedUint8Array>;
    import { bytes } from 'node:stream/consumers';
import { Readable } from 'node:stream';
import { Buffer } from 'node:buffer';

const dataBuffer = Buffer.from('hello world from consumers!');

const readable = Readable.from(dataBuffer);
const data = await bytes(readable);
console.log(`from readable: ${data.length}`);
// Prints: from readable: 27
    @returns

    Fulfills with a Uint8Array containing the full contents of the stream.

  • function json(
    stream: ReadableStream | AsyncIterable<any, any, any> | ReadableStream<any>
    ): Promise<unknown>;
    import { json } from 'node:stream/consumers';
import { Readable } from 'node:stream';

const items = Array.from(
  {
    length: 100,
  },
  () => ({
    message: 'hello world from consumers!',
  }),
);

const readable = Readable.from(JSON.stringify(items));
const data = await json(readable);
console.log(`from readable: ${data.length}`);
// Prints: from readable: 100
    @returns

    Fulfills with the contents of the stream parsed as a UTF-8 encoded string that is then passed through JSON.parse().

  • function text(
    stream: ReadableStream | AsyncIterable<any, any, any> | ReadableStream<any>
    ): Promise<string>;
    import { text } from 'node:stream/consumers';
import { Readable } from 'node:stream';

const readable = Readable.from('Hello world from consumers!');
const data = await text(readable);
console.log(`from readable: ${data.length}`);
// Prints: from readable: 27
    @returns

    Fulfills with the contents of the stream parsed as a UTF-8 encoded string.