What are some advanced mocking techniques in Node.js?

What are some advanced mocking techniques in Node.js?

Advanced mocking techniques in Node.js include using libraries like Sinon.js for spies, stubs, and mocks, as well as leveraging dependency injection to isolate components.

Can you explain how to use Sinon.js for mocking?

Sure! Sinon.js allows you to create spies, stubs, and mocks. You can use sinon.spy() to track function calls, sinon.stub() to replace a function with a fake implementation, and sinon.mock() to create a mock object.

What is the difference between a spy and a stub?

A spy records the calls made to a function without changing its behavior, while a stub replaces the function with a fake implementation that you can control.

How can I test asynchronous code with mocks?

You can test asynchronous code by using promises or async/await in your tests. Sinon.js can help you mock the asynchronous functions to control their behavior during tests.