Cypress Plugin

Cypress is an e2e test runner built for modern web. It has a lot of great features:

Time travel
Real-time reloads
Automatic waiting
Spies, stubs, and clocks
Network traffic control
Screenshots and videos

Setting Up Cypress

Generating Applications

By default, when creating a new frontend application, Nx will use Cypress to create the e2e tests project.

nx g @nrwl/web:app frontend

Creating a Cypress E2E project for an existing project

You can create a new Cypress E2E project for an existing project.

If the @nrwl/cypress package is not installed, install the version that matches your @nrwl/workspace version.

yarn add --dev @nrwl/cypress

npm install --save-dev @nrwl/cypress

Next, generate an E2E project based on an existing project.

nx g @nrwl/cypress:cypress-project your-app-name-e2e --project=your-app-name

Replace your-app-name with the app's name as defined in your workspace.json file.

Using Cypress

Testing Applications

Simply run nx e2e frontend-e2e to execute e2e tests with Cypress.

By default, Cypress will run in “headed” mode (you will see the tests executing in a new browser window). You will have the result of all the tests and errors (if any) in your terminal.

Screenshots and videos will be accessible in dist/apps/frontend/screenshots and dist/apps/frontend/videos.

Watching for Changes

With, nx e2e frontend-e2e --watch Cypress will start in the application mode.

Running Cypress with --watch is a great way to enhance dev workflow - you can build up test files with the application running and Cypress will re-run those tests as you enhance and add to the suite.

Cypress doesn't currently re-run your tests after changes are made to application code when it runs in “headed” mode. There is an open feature request to add this behaviour.

Using Cypress in the Headless Mode

If you want to run the Cypress tests in headless mode (e.g., on CI), you can do so by passing --headless. You will see all the test results live in the terminal. Videos and screenshots will be available for debugging.

In headless mode your tests will be re-run every time you make a change to your application code.

Testing Against Prod Build

You can run your e2e test against a production build like this: nx e2e frontend-e2e --prod.

Configuration

Specifying a Custom Url to Test

The baseUrl property provides you the ability to test an application hosted on a specific domain.

nx e2e frontend-e2e --baseUrl=https://frontend.com

If no baseUrl and no devServerTarget are provided, Cypress will expect to have the baseUrl property in the cypress.json file, or will error.

Using cypress.json

If you need to fine tune your Cypress setup, you can do so by modifying cypress.json in the e2e project. For instance, you can easily add your projectId to save all the screenshots and videos into your Cypress dashboard. The complete configuration is documented on the official website.