Simple E2E test suite with Cypress

👈 click here to see test results on Cypress dashboard

application under test: http://angularjs.realworld.io/

🎉 Learn how to write these tests and more in our trainings bigbyte.academy 🎉

🥅 Goals

• keep it simple - no 'custom' abstractions/functions/utils/helpers (use what Cypress provides)
• tests are easily readable
• project is easily understandable even to people without previous JS or Cypress knowledge
• use shortcuts to avoid repeating/testing the same UI actions over and over again

⚙️ Setup

1. git clone https://github.com/helenanull/cypress-example.git
2. cd to cypress-example folder and run npm install

✔️ Run tests

• If you installed Cypress via npm:

  • cypress test runner (cypress open):

    • npm run cy:open:web OR cypress open --env device=web (change web to mob to run tests on mobile view)

  • cypress headless mode (cypress run):

    • npm run cy:run:web OR cypress run --env device=web
• If you installed Cypress zip:
  • import cypress-example folder and you are good to go

💡 Information

ℹ️ Feel free to delete .circleCI folder and Jenkinsfile from your machine. (These files are for CI to run tests automatically once a week)

🧪 Tests

📁 Tests are located in cypress/e2e folder

📁 Custom commands are located in cypress/support folder (.cmd.js suffix)

📁 Selectors (CSS selectors) are located in cypress/selectors folder [only difference from cypress default project structure] - not using page object model(POM) design pattern but keeping selectors (only selectors) separately Read more

🛠️ Configuration

Config files:

1. cypress.config.js - Main config file where default behavior of Cypress can be modified. More info
2. plugins/index.js - Plugins file is where we can programmatically alter the resolved configuration More info

This test suite is supporting multiple viewports (mobile and desktop). See plugins/index.js file

One solution is to use cy.viewport() command inside the test, to change the viewports, but very often websites also check user agent to get the device information(and show the mobile view). Since user agent is something we can't change in the middle of the test, we need to pass config value when launching tests. In cypress.config.js we have a device parameter and in plugins file index.js, we decide viewports and user agent parameter values based on that device value.

💠 IDE setup and recommended extensions

• VS Code with following extensions:
  • ESLint - to keep your code tidy
  • Add Only - enables to add/remove .only with one click
  • Mocha snippets

❔ Q&A

1. Why keep selectors separately (not hard-coded to tests)
   • tests are much more readable - css selectors are by design hard to read - even if we add data-test attributes. We might need a 2nd child or want to verify that a selector is a child of another element, like .class2 > ul:nth-child(2) (alternative get().find() or get().parent() is bad practice because of this )
   • in large projects, we might need to re-use the same selectors. Example: in login test, we want to verify that login was successful and for that, we check settings link visibility in header. But the same settings link is also used in header test.
   • selector and test logic is separated - when selector is updated, we just need to update 1 selector file and not multiple tests
2. Is it still E2E test if we use API's instead of UI?

   • all functionality should be tested from UI once. There is no reason to repeat the same UI actions over and over again in each test. Edit article example. End result will be the same - it will catch exactly the same bugs as full flow/user journey test would find, (we need to be careful not to leave 'gaps' though) - tests are faster, more stable and independent with this approach, test suite is still E2E.

     Example: Application/website has a bug where login button is not working - this means that settings(and other tests) would still pass since we log in programmatically, but login test would fail because we actually click on the button like users do.

🔗 Links

1. https://www.youtube.com/watch?v=5XQOK0v_YRE&ab_channel=OKG%21
2. https://docs.cypress.io/guides/references/best-practices.html
3. https://docs.cypress.io/api/cypress-api/custom-commands.html#Best-Practices