What is @types/sinonjs__fake-timers?
@types/sinonjs__fake-timers provides TypeScript type definitions for the sinonjs/fake-timers library, which allows you to control the flow of time in your JavaScript code. This is particularly useful for testing code that relies on timers, such as setTimeout, setInterval, and Date.
What are @types/sinonjs__fake-timers's main functionalities?
Controlling setTimeout
This feature allows you to control the behavior of setTimeout, making it easier to test code that relies on delayed execution.
const sinon = require('sinon');
const clock = sinon.useFakeTimers();
setTimeout(() => {
console.log('This will be printed after 2 seconds');
}, 2000);
clock.tick(2000); // Fast-forwards time by 2000ms
Controlling setInterval
This feature allows you to control the behavior of setInterval, making it easier to test code that relies on repeated execution.
const sinon = require('sinon');
const clock = sinon.useFakeTimers();
let count = 0;
const intervalId = setInterval(() => {
count += 1;
console.log('Interval count:', count);
}, 1000);
clock.tick(3000); // Fast-forwards time by 3000ms
clearInterval(intervalId);
Mocking Date
This feature allows you to mock the Date object, making it easier to test code that relies on the current date and time.
const sinon = require('sinon');
const clock = sinon.useFakeTimers(new Date(2020, 1, 1));
console.log(new Date()); // Outputs: 2020-02-01T00:00:00.000Z
clock.tick(86400000); // Fast-forwards time by 1 day
console.log(new Date()); // Outputs: 2020-02-02T00:00:00.000Z
Other packages similar to @types/sinonjs__fake-timers
jest
Jest is a JavaScript testing framework that comes with built-in utilities for mocking timers. It provides similar functionalities to @types/sinonjs__fake-timers, such as jest.useFakeTimers() and jest.advanceTimersByTime(). Jest is more comprehensive as it includes a full testing framework along with timer mocks.
lolex
Lolex is a standalone library for creating fake timers, similar to sinonjs/fake-timers. It allows you to control the flow of time in your tests. Lolex is often used as a dependency in other testing libraries, including Sinon itself.