mock-clock-js

An asynchronous mock clock library for javascript unit testing.

Installation

npm install mock-clock --save-dev

Usage

This library allows you to mock the clock in your Javascript unit tests, giving you more control over the value of the current time and the behavior of timers.

Unlike other implementations, ticking the clock is always an async operation. When testing code that mixes Promises and timer behavior, it can be difficult (and potentially undesirable) to truly flatten all behavior into a synchronous path.

Let's jump into an example...

var clock = require('mock-clock');

describe('my tests', function () {
    beforeEach(clock.install);
    afterEach(clock.uninstall);

    it('runs something every 500ms', function (done) {
        var frames = [];
        setInterval(function () {
            frames.push(true);
        }, 500);

        expect(frames).toEqual([]);
        clock.tick(499).then(function () {
            expect(frames).toEqual([]);
            return clock.tick(1);
        }).then(function () {
            expect(frames).toEqual([true]);
        }).then(clock.ticks(500)).then(function () {
            expect(frames).toEqual([true, true]);
            done();
        });
    });
});

API

WIP

License

Licensed under MIT. Full license here »

Contributing

Pull requests are welcome. Make sure to include tests for any new or modified functionality.

Feature requests and issue reports are also welcome. When reporting an issue be sure to include operating system, node version, and any other information required to reproduce the problem.