How do I test asynchronous code with Jest using async/await?

How do I test asynchronous code with Jest using async/await?

You can test asynchronous code in Jest by using the async keyword in your test function and await for the promises.

Can you show me a simple example?

Sure! Here's a basic example:

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

What if the promise is rejected?

In that case, you can use try...catch to handle the error. Here's an example:

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

Is there a way to test multiple async functions?

Yes! You can use Promise.all to test multiple async functions in parallel. Here's how:

test('fetches multiple data', async () => {
  const [data1, data2] = await Promise.all([fetchData1(), fetchData2()]);
  expect(data1).toEqual(expectedData1);
  expect(data2).toEqual(expectedData2);
});