Converting a Buffer into a ReadableStream in Node.js

For nodejs 10.17.0 and up:

const { Readable } = require('stream');

const stream = Readable.from(myBuffer.toString());

something like this...

import { Readable } from 'stream'

const buffer = new Buffer(img_string, 'base64')
const readable = new Readable()
readable._read = () => {} // _read is required but you can noop it
readable.push(buffer)
readable.push(null)

readable.pipe(consumer) // consume the stream

In the general course, a readable stream's _read function should collect data from the underlying source and push it incrementally ensuring you don't harvest a huge source into memory before it's needed.

In this case though you already have the source in memory, so _read is not required.

Pushing the whole buffer just wraps it in the readable stream api.

Node Stream Buffer is obviously designed for use in testing; the inability to avoid a delay makes it a poor choice for production use.

Gabriel Llamas suggests streamifier in this answer: How to wrap a buffer as a stream2 Readable stream?