How do you stub a function in Sinon?

Create a file called lib.js and add the following code :

  1. module.
  2. // app.js file const lib = require(‘./lib’) console.
  3. # run the app.js file node app.js.
  4. # installing sinon npm install –save-dev sinon.

What are stubs Sinon?

Test stubs are functions (spies) with pre-programmed behavior. They support the full test spy API in addition to methods which can be used to alter the stub’s behavior. As spies, stubs can be either anonymous, or wrap existing functions.

How stub promise all Sinon?

Very simple, one just have to stub the function that will return the Promise, use the function returnsPromise. After that, you just have to the if the Promise will resolve and reject. Oh yeah! And if you’re using karma to run your tests there’s even a plugin for that karma-sinon-stub-promise.

How do you mock a class with Sinon?

How to properly mock ES6 classes with sinon

  1. Class A class A { constructor(b) { this. b = b; } doSomething(id) { return new Promise( (resolve, reject) => { this.
  2. Class B class B { constructor() {} doOther() { return new Promise( (resolve, reject) => { // various things that will resolve or reject }); } module.
  3. index.

How do I reset my Sinon stub?

reset() and restore() One important function to remember is sinon. reset() , which resets both the behavior and history of all stubs. If you just want to reset a specific stub you can use stub. reset() .

What is Sinon used for?

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.

What is Sinon sandbox?

var sandbox = sinon. The sinon. createSandbox(config) method is often an integration feature, and can be used for scenarios including a global object to coordinate all fakes through. Sandboxes are partially configured by default such that calling: var sandbox = sinon.

What is stub in Java?

A stub is a controllable replacement for an existing dependency (or collaborator) in the system. By using a stub, you can test your code without dealing with the dependency directly. A mock object is a fake object in the system that decides whether the unit test has passed or failed.

What is stub method in Java?

A method stub or simply stub in software development is a piece of code used to stand in for some other programming functionality. A stub may simulate the behavior of existing code (such as a procedure on a remote machine; such methods are often called mocks) or be a temporary substitute for yet-to-be-developed code.

What is Sinon restore?

The restore functions in sinon only work on spies and stubs that replace an existing method, and our spy was created as an anonymous (standalone) spy. Therefore, restore does not reset the call count, which will continue increasing as the spy function is called in subsequent tests.