How do I test async lifecycle hooks in Vue with Vue Test Utils?

How do I test async lifecycle hooks in Vue with Vue Test Utils?

To test async lifecycle hooks in Vue, you can use Vue Test Utils along with Jest or Mocha. You can mount your component and then use await to wait for the async operations to complete.

Can you give me a code example?

Sure! Here's a simple example:

import { mount } from '@vue/test-utils';
import MyComponent from '@/components/MyComponent.vue';

test('async lifecycle hook', async () => {
  const wrapper = mount(MyComponent);
  await wrapper.vm.$nextTick(); // wait for the next tick
  // Now you can assert the expected behavior
});

What if I need to test a promise that resolves in the lifecycle hook?

You can mock the promise in your test. For example:

jest.mock('@/api', () => ({ fetchData: jest.fn(() => Promise.resolve('data')) }));

test('async lifecycle with promise', async () => {
  const wrapper = mount(MyComponent);
  await wrapper.vm.$nextTick();
  // Assert the expected behavior after the promise resolves
});