How do I test side effects in functions?

How do I test side effects in functions?

To test side effects in functions, you can use unit testing frameworks like Jest or Mocha. They allow you to assert the expected outcomes.

Can you give me an example of a function with side effects?

Sure! A function that modifies a global variable or interacts with the DOM is a common example. For instance, a function that updates a user interface element.

What tools can I use for testing these side effects?

You can use tools like Jest for JavaScript, or Pytest for Python. They provide features to mock functions and assert side effects.

How do I mock a function in Jest?

In Jest, you can use jest.fn() to create a mock function. You can then track calls and assert how it was called.