What is the best way to test Vue.js components with Cypress?

2 Setting up Cypress

To use Cypress with Vue.js, you need to install it as a dev dependency in your project. You can do this by running the following command in your terminal: npm install --save-dev cypress This will create a cypress folder in your project root, where you will find the configuration file (cypress.json), the integration tests folder (cypress/integration), and some example tests. You can also open the Cypress test runner by running the following command: npx cypress open This will launch a window where you can see and run your tests. To test Vue.js components, you also need to install some additional plugins that will help you mount and interact with your components in the browser. One of these plugins is @cypress/vue, which lets you use the Vue Test Utils library to mount your components. You can install it by running: npm install --save-dev @cypress/vue You also need to configure Cypress to use this plugin by adding the following code to your cypress/support/index.js file: import { mount } from '@cypress/vue' Cypress.Commands.add('mount', mount) This will create a custom command called mount that you can use in your tests to render your components.

3 Writing and running tests

To write tests for your Vue.js components, you need to create a spec file in your cypress/integration folder. A spec file is a JavaScript file that contains one or more tests, each of which is composed of a description and a function. For example, you can create a spec file called HelloWorld.spec.js with the following content: describe('HelloWorld component', () => { it('renders a message', () => { // import the component to test import HelloWorld from '../../src/components/HelloWorld.vue' // mount the component in the browser cy.mount(HelloWorld) // assert that the component contains the expected message cy.contains('Hello Vue 3 + Vite') }) }) This is a simple test that checks that the HelloWorld component renders a message in the browser. To run this test, you can open the Cypress test runner and click on the HelloWorld.spec.js file. You will see the test result and the component in the browser. You can also use the Cypress commands and assertions to interact with and verify the component. For example, you can click on a button, enter some input, check the URL, or take a screenshot of the component. You can find the full list of Cypress commands and assertions in the official documentation.

4 Using plugins and utilities

Cypress offers a variety of plugins and utilities to enhance testing with Vue.js. For instance, the @cypress/code-coverage plugin lets you measure code coverage of components and generate reports with some configuration in cypress/plugins/index.js and cypress/support/index.js files. The cypress-axe plugin enables accessibility checks using axe-core library, which requires importing and configuring it in cypress/support/index.js. Additionally, the cypress-vue-devtools utility allows you to use Vue Devtools extension with configuration in vite.config.js and cypress/plugins/index.js files. These are just some examples of the plugins and utilities available for Cypress and Vue.js; more can be found in the Cypress plugins directory and the Cypress Vue recipes repository.