What is mocha chai and Sinon?
json file under “scripts”: { “test”: “mocha” } . Chai – A library that adds extra readability to JavaScript test assertions. Supplants the Node. Sinon – A library that provides spies that “watch” functions and can detect when they’re called, what arguments are passed to them, what is returned, etc.
What is Sinon and chai?
Sinon–Chai provides a set of custom assertions for using the Sinon. JS spy, stub, and mocking framework with the Chai assertion library. You get all the benefits of Chai with all the powerful tools of Sinon.
What is Sinon in node JS?
Sinon JS is a popular JavaScript library that lets you replace complicated parts of your code that are hard to test for “placeholders,” so you can keep your unit tests fast and deterministic, as they should be.
Can I use Sinon with jest?
Jest is a popular, open-source test framework for JavaScript. We can use Jest to create mocks in our test – objects that replace real objects in our code while it’s being tested. js, we covered how we can use Sinon. js to stub, spy, and mock Node.
What does Sinon stub do?
Sinon splits test-doubles into three types: Spies, which offer information about function calls, without affecting their behavior. Stubs, which are like spies, but completely replace the function. This makes it possible to make a stubbed function do whatever you like — throw an exception, return a specific value, etc.
Why do we use Sinon?
Put simply, Sinon allows you to replace the difficult parts of your tests with something that makes testing simple. When testing a piece of code, you don’t want to have it affected by anything outside the test. If something external affects a test, the test becomes much more complex and could fail randomly.
What is a Sinon sandbox?
JS. Sandboxes simplify working with fakes that need to be restored and/or verified. If you’re using fake timers, fake XHR, or you are stubbing/spying on globally accessible properties you should use a sandbox to ease cleanup.
Do you need Sinon with Jest?
Fake timers are already implemented into Jest, so there’s no need for Sinon. Tell the test you’re going to use fake timers with jest.
What is Sinon sandbox?
What is Sinon restore?
restore() just restores the behavior of the stubbed functionality but it doesn’t reset the state of the stubs. You’ll have to either wrap your tests with sinon.test and use this.stub or individually call reset() on the stubs.
How does Sinon spy work?
The primary use for spies is to gather information about function calls. You can also use them to help verify things, such as whether a function was called or not. The function sinon. spy returns a Spy object, which can be called like a function, but also contains properties with information on any calls made to it.
Can I use Sinon in Jest?