Sources

from(input): AsyncIterable

Create an async byte stream from the given input. Strings are UTF-8 encoded. ArrayBuffer and ArrayBufferView values are wrapped as Uint8Array. Arrays and iterables in input are recursively flattened and normalized. Flattened values may be split across implementation-defined bounded batches.

Objects implementing Symbol.for('Stream.toAsyncStreamable') or Symbol.for('Stream.toStreamable') are converted via those protocols. The toAsyncStreamable protocol takes precedence over toStreamable, which takes precedence over the iteration protocols (Symbol.asyncIterator, Symbol.iterator).

import { Buffer } from 'node:buffer';
import { from, text } from 'node:stream/iter';

console.log(await text(from('hello')));       // 'hello'
console.log(await text(from(Buffer.from('hello')))); // 'hello'

const { Buffer } = require('node:buffer');
const { from, text } = require('node:stream/iter');

async function run() {
  console.log(await text(from('hello')));       // 'hello'
  console.log(await text(from(Buffer.from('hello')))); // 'hello'
}

run().catch(console.error);

fromSync(input): Iterable

Synchronous version of from(). Returns a sync iterable. Cannot accept async iterables or promises. Objects implementing Symbol.for('Stream.toStreamable') are converted via that protocol (takes precedence over Symbol.iterator). The toAsyncStreamable protocol is ignored entirely.

import { fromSync, textSync } from 'node:stream/iter';

console.log(textSync(fromSync('hello'))); // 'hello'

const { fromSync, textSync } = require('node:stream/iter');

console.log(textSync(fromSync('hello'))); // 'hello'