nstdlib-nightly/lib/stream/consumers.mjs

Node.js standard library converted to runtime-agnostic ES modules.

// Source: https://github.com/nodejs/node/blob/65eff1eb/lib/stream/consumers.js

import { TextDecoder } from "nstdlib/lib/internal/encoding";
import { Blob } from "nstdlib/lib/internal/blob";
import { Buffer } from "nstdlib/lib/buffer";

/**
 * @typedef {import('../internal/webstreams/readablestream').ReadableStream
 * } ReadableStream
 * @typedef {import('../internal/streams/readable')} Readable
 */

/**
 * @param {AsyncIterable|ReadableStream|Readable} stream
 * @returns {Promise<Blob>}
 */
async function blob(stream) {
  const chunks = [];
  for await (const chunk of stream) chunks.push(chunk);
  return new Blob(chunks);
}

/**
 * @param {AsyncIterable|ReadableStream|Readable} stream
 * @returns {Promise<ArrayBuffer>}
 */
async function arrayBuffer(stream) {
  const ret = await blob(stream);
  return ret.arrayBuffer();
}

/**
 * @param {AsyncIterable|ReadableStream|Readable} stream
 * @returns {Promise<Buffer>}
 */
async function buffer(stream) {
  return Buffer.from(await arrayBuffer(stream));
}

/**
 * @param {AsyncIterable|ReadableStream|Readable} stream
 * @returns {Promise<string>}
 */
async function text(stream) {
  const dec = new TextDecoder();
  let str = "";
  for await (const chunk of stream) {
    if (typeof chunk === "string") str += chunk;
    else str += dec.decode(chunk, { stream: true });
  }
  // Flush the streaming TextDecoder so that any pending
  // incomplete multibyte characters are handled.
  str += dec.decode(undefined, { stream: false });
  return str;
}

/**
 * @param {AsyncIterable|ReadableStream|Readable} stream
 * @returns {Promise<any>}
 */
async function json(stream) {
  const str = await text(stream);
  return JSONParse(str);
}

export { arrayBuffer };
export { blob };
export { buffer };
export { text };
export { json };