Stream Mock

Mock nodejs streams.

Features

Create a readable stream from any iterable.
Create a writable stream that puts its data at your disposal.
Create a duplex stream that combines a readable and writable stream together.
Can operate both in object and normal ( Buffer ) mode.

Quick start

yarn add stream-mock

Or, if you are more a npm person

npm i stream-mock

Basic usage

You are building an awesome brand new Transform stream that rounds all your values.

import { Transform } from 'stream';

export default class Rounder extends Transform {
  _transform(chunk, encoding, callback) {
    this.push(Math.round(chunk));
    callback();
  }
}

Now you need / want to test it.

import { ObjectReadableMock, ObjectWritableMock } from 'stream-mock';
import chai from 'chai';

import Rounder from 'the/seven/bloody/hells';

chai.should();

describe('Test me if you can', (done) => {
    it('Round me like one of your french girls', {
        // Given
        const input = [1.2, 2.6, 3.7];
        const transform = new Rounder({objectMode: true});
        const reader = new ObjectReadableMock(input);
        const writer = new ObjectWritableMock();
        // When
        reader.pipe(transform).pipe(writer);
        // Then
        writer.on('finish', ()=>{
            writer.data.should.deep.equal(input.map(Math.round));
        })
    });
});