What are async tests in Jest and how do I use them?

What are async tests in Jest and how do I use them?

Async tests in Jest allow you to test asynchronous code, such as promises or callbacks. You can use async/await or return a promise.

Can you show me an example of an async test using Jest?

Sure! Here's a simple example:

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

What if my async function throws an error?

You can use try/catch within your async test to handle errors. For example:

test('handles error', async () => {
  try {
    await fetchData();
  } catch (e) {
    expect(e).toEqual(expectedError);
  }
});

Are there any best practices for writing async tests?

Yes! Always use async/await for better readability, avoid using done() callback, and ensure to handle errors properly.