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
How to Use Cypress
By default, when creating a new frontend application, Nx will use Cypress to create the e2e tests project.
nx g @nrwl/web:app frontend
<workspace name>/ ├── apps/ │ ├── frontend/ │ └── frontend-e2e/ │ ├── src/ │ │ ├── fixtures/ │ │ │ └── example.json │ │ ├── integration/ │ │ │ └── app.spec.ts │ │ ├── plugins/ │ │ │ └── index.ts │ │ └── support/ │ │ ├── app.po.ts │ │ ├── commands.ts │ │ └── index.ts │ ├── cypress.json │ ├── tsconfig.e2e.json │ └── tsconfig.json ├── libs/ ├── tools/ ├── nx.json ├── package.json ├── README.md ├── workspace.json └── tsconfig.base.json
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
Watching for Changes
ng 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.
Specifying a Custom Url to Test
baseUrl property provides you the ability to test an application hosted on a specific domain.
nx e2e frontend-e2e --baseUrl=https://frontend.com
devServerTargetare provided, Cypress will expect to have the
baseUrlproperty in the
cypress.jsonfile, or will error.
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.