standardized-audio-context-mock

A mocked version of the standardized-audio-context module.


This library is meant to test code which is using standardized-audio-context without acutally rendering any audio.

It does depend on Sinon.JS to do the mocking.

Usage

standardized-audio-context-mock is published on
npm and can be installed as usual.

``shell
npm install standardized-audio-context-mock
`

Testing

Let's say you have the following code that you want to test:

`typescript
// File ./play.ts
import { IAudioBuffer, IAudioContext } from 'standardized-audio-context';

export const play = (audioBuffer: IAudioBuffer, audioContext: IAudioContext) => {
const audioBufferSourceNode = audioContext.createBufferSource();

audioBufferSourceNode.buffer = audioBuffer;
audioBufferSourceNode.connect(audioContext.destination);

audioBufferSourceNode.start();
};
`

A test suite for the play() function which will run with Mocha and Chai and uses standardized-audio-context-mock might look like this:

`js
// File ./play.test.js
import { AudioBuffer, AudioContext, registrar } from 'standardized-audio-context-mock';
import { play } from './play';

describe('play()', () => {
let audioBufferMock;
let audioContextMock;

afterEach(() => registrar.reset());

beforeEach(() => {
audioBufferMock = new AudioBuffer({ length: 10, sampleRate: 44100 });
audioContextMock = new AudioContext();
});

it('should create a new AudioBufferSourceNode', () => {
play(audioBufferMock, audioContextMock);

expect(registrar.getAudioNodes(audioContextMock, 'AudioBufferSourceNode')).to.have.a.lengthOf(1);
});

it('should set the buffer property of the AudioBufferSourceNode', () => {
play(audioBufferMock, audioContextMock);

const [audioBufferSourceNodeMock] = registrar.getAudioNodes(audioContextMock, 'AudioBufferSourceNode');

expect(audioBufferSourceNodeMock.buffer).to.equal(audioBufferMock);
});

it('should connect the AudioBufferSourceNode with to destination', () => {
play(audioBufferMock, audioContextMock);

const [audioBufferSourceNodeMock] = registrar.getAudioNodes(audioContextMock, 'AudioBufferSourceNode');

expect(audioBufferSourceNodeMock.connect).to.have.been.calledOnce;
expect(audioBufferSourceNodeMock.connect).to.have.been.calledWithExactly(audioContextMock.destination);
});

it('should start the AudioBufferSourceNode', () => {
play(audioBufferMock, audioContextMock);

const [audioBufferSourceNodeMock] = registrar.getAudioNodes(audioContextMock, 'AudioBufferSourceNode');

expect(audioBufferSourceNodeMock.start).to.have.been.calledOnce;
});
});
``