What are some examples of using Jest mocks?

What are some examples of using Jest mocks?

Jest mocks are used to simulate functions or modules in tests. For example, you can mock a function to control its behavior.

Can you show me a simple code example?

Sure! Here's a basic example:

const myFunction = jest.fn();
myFunction.mockReturnValue('Hello, World!');
console.log(myFunction()); // Outputs: Hello, World!

How do I mock a module instead of a function?

You can use jest.mock() to mock a module. For instance:

jest.mock('./myModule');
import myModule from './myModule';
myModule.mockReturnValue('Mocked Value');

What about testing asynchronous functions?

For async functions, you can use jest.fn() with async/await. Here's an example:

const fetchData = jest.fn().mockResolvedValue('Data');
const data = await fetchData();
console.log(data); // Outputs: Data