freeCodeCamp/docs/how-to-add-cypress-tests.md

# How to add Cypress tests

When making changes to JavaScript, CSS, or HTML which could change the functionality or layout of a page, it's important to add corresponding [Cypress](https://docs.cypress.io) integration tests.

To learn how to write Cypress tests, or 'specs', please see Cypress' official [documentation](https://docs.cypress.io/guides/getting-started/writing-your-first-test.html).

> Note: When writing tests for freeCodeCamp, remember to add `/* global cy */` to the top of the file to avoid ESLint issues.

### Where to add a test

- Cypress tests are in the `./cypress` directory.

- Cypress tests for a curriculum module are in the corresponding curriculum directory, i.e. `cypress/integration/learn/responsive-web-design/basic-css/index.js`.

### How to run tests

**1. Ensure that MongoDB and client applications are running**

  - [Start MongoDB and seed the database](/how-to-setup-freecodecamp-locally#step-3-start-mongodb-and-seed-the-database)

  - [Start the freeCodeCamp client application and API server](/how-to-setup-freecodecamp-locally#step-4-start-the-freecodecamp-client-application-and-api-server)
 
**2. Run the cypress tests**

  To run tests against production builds, replace `dev` with `prd` below.

  - To run all tests in the `./cypress` directory:

    ```console
    npm run cypress:dev:run
    ```

  - To run a single test:

    ```console 
    npm run cypress:dev:run -- --spec=cypress/pathToYourSpec/youSpecFileName.js
    ```

  - To create a development build, start the development server, and run all existing cypress end-to-end tests:

    ```console 
    npm run e2e:dev:run
    ```