What is the difference between async and sync tests in Jest?

What is the difference between async and sync tests in Jest?

In Jest, sync tests run immediately and return results right away, while async tests handle operations that take time, like API calls.

Can you give me an example of an async test in Jest?

Sure! An async test can use async/await to wait for a promise to resolve before making assertions. For example:

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

What about sync tests? How do they look?

Sync tests are straightforward. For example:

test('adds 1 + 2 to equal 3', () => {
  expect(1 + 2).toBe(3);
});

When should I use async tests?

Use async tests when your code involves operations that return promises, like fetching data from an API or reading files.