Snapshot testing with Jest is a powerful way to ensure that your Vue.js components render correctly and consistently. It involves capturing a snapshot of the component's rendered output and comparing it to a previously stored snapshot. In this guide, we'll explore how to perform snapshot testing in Vue.js using Jest and provide sample code to demonstrate the process.

Sample Code

Let's create a Vue.js component and write a Jest test to perform snapshot testing:

// MyComponent.vue
<h1>Hello, Snapshot Test!</h1>
<p>This is a snapshot test example.</p>
// MyComponent.test.js
import { mount } from '@vue/test-utils';
import MyComponent from './MyComponent.vue';
test('MyComponent snapshot test', () => {
const wrapper = mount(MyComponent);

In this code:

  • We create a simple Vue.js component named `MyComponent` that displays a greeting message.
  • For testing purposes, we write a Jest test in a separate file (`MyComponent.test.js`).
  • In the test, we use `@vue/test-utils` to mount the `MyComponent` and capture its rendered HTML.
  • We then use Jest's `toMatchSnapshot` matcher to compare the rendered HTML to a previously stored snapshot.