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.

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'