Corti is a mock implementation of the browser’s SpeechRecognition API (aka webkitSpeechRecognition) for automated testing. It helps developers simulate speech recognition functionalities and test their applications in a controlled environment without relying on actual speech input.
💡 To easily use Speech Recognition in your own project, check out annyang.
- Mock SpeechRecognition API for testing purposes (can replace window.SpeechRecognition, window.webkitSpeechRecognition, window.mozSpeechRecognition, etc.)
- Compatible with all JavaScript testing frameworks
- Can be required (CJS), imported (ESM), or included via a script tag for testing in Node.js or in a browser
- Adds additional functionality to the SpeechRecognition API to support programmatically simulating speech and checking the current status
Install corti as a dev dependency using npm / pnpm / bun / yarn / etc:
npm install --save-dev corti// Vitest example
import { SpeechRecognition } from 'corti';
import { describe, it, expect, beforeEach, beforeAll, afterAll, vi } from 'vitest';
beforeAll(() => {
vi.stubGlobal('SpeechRecognition', SpeechRecognition);
});
afterAll(() => {
vi.unstubAllGlobals();
});
describe('Mirror mirror on the wall', () => {
let recognition;
let spyFn;
beforeEach(() => {
recognition = new globalThis.SpeechRecognition();
spyFn = vi.fn();
recognition.maxAlternatives = 5;
recognition.onresult = spyFn;
recognition.start();
});
it('should call callback when called with a single sentence', () => {
recognition.say('Hello world');
expect(spyFn).toHaveBeenCalled();
const event = spyFn.mock.calls[0][0];
expect(event.results[0][0].transcript).toBe('Hello world');
});
it('should call callback when called with multiple sentences', () => {
recognition.say(['Hello world', 'How are you?']);
expect(spyFn).toHaveBeenCalled();
const event = spyFn.mock.calls[0][0];
expect(event.results[0][0].transcript).toBe('Hello world');
expect(event.results[0][1].transcript).toBe('How are you?');
});
});// Jest example
const { SpeechRecognition } = require('corti');
beforeAll(() => {
global.SpeechRecognition = SpeechRecognition;
});
test('SpeechRecognition', () => {
const speech = new globalThis.SpeechRecognition();
const spyFn = jest.fn();
speech.onresult = spyFn;
speech.continuous = true;
speech.start();
speech.say('Hello world');
speech.say('Hello world');
expect(spyFn.mock.calls.length).toBe(2);
});<script type="module">
// Mock native SpeechRecognition
import { SpeechRecognition } from 'corti.js';
window.SpeechRecognition = SpeechRecognition;
// Run some tests
const recognition = new window.SpeechRecognition();
recognition.onresult = () => console.log('I hear it!');
recognition.start();
recognition.say('Hello world');
</script><script src="../dist/corti.js"></script>
<script>
// Mock native SpeechRecognition
window.SpeechRecognition = corti.SpeechRecognition;
// Run some tests
const recognition = new window.SpeechRecognition();
recognition.onresult = () => console.log('I hear it!');
recognition.start();
recognition.say('Hello world');
</script>For an example of how Corti is used in a real project, check out how SpeechRecognition is mocked and tested in Corti.
start()abort()stop()addEventListener()
interimResultslangcontinuousmaxAlternativesonstartonendonresultonsoundstart
startendresultsoundstart
SpeechRecognitionSpeechRecognitionEventSpeechRecognitionResultListSpeechRecognitionResultSpeechRecognitionAlternative
isStarted()say()
Tal Ater: @TalAter
Licensed under MIT.