What is Jest async testing and how do I use it?

What is Jest async testing and how do I use it?

Jest async testing allows you to test asynchronous code in JavaScript. You can use async/await or return a promise.

Can you show me an example of testing a promise with Jest?

Sure! Here's a simple example:

test('fetches data', async () => {
  const data = await fetchData();
  expect(data).toEqual(expectedData);
});

What if I want to test an async function that throws an error?

You can use rejects to test for errors. For example:

await expect(asyncFunction()).rejects.toThrow('error message');

Are there any best practices for async testing in Jest?

Yes! Always use async/await for better readability, and ensure to handle both resolved and rejected promises.