Test isolation strategies in Cypress - Framework Patterns

Framework Mode - Test isolation strategies

Folder Structure

cypress/
├── e2e/                  # Test specs
│   ├── login.cy.js       # Example test file
│   └── dashboard.cy.js
├── fixtures/             # Test data files (JSON, etc.)
│   └── user.json
├── support/              # Custom commands and utilities
│   ├── commands.js       # Custom Cypress commands
│   └── index.js          # Support file loaded before tests
cypress.config.js         # Cypress configuration file

Test Framework Layers

• Test Specs (cypress/e2e): Actual test files where test cases are written. Each test should be independent.
• Fixtures (cypress/fixtures): Static test data used to keep tests consistent and isolated.
• Support (cypress/support): Contains reusable commands and setup code to keep tests clean and isolated.
• Configuration (cypress.config.js): Defines environment variables, base URLs, and test settings to isolate test environments.

Configuration Patterns

• Environment Variables: Use env in cypress.config.js to set different URLs, credentials, or flags for dev, staging, and prod.
• Test Isolation: Use testIsolation: true in Cypress config to reset state between tests automatically.
• Fixtures: Load test data from fixtures to avoid hardcoding and keep tests independent.
• BeforeEach Hooks: Use beforeEach() in tests to reset app state or visit fresh pages to isolate tests.

Test Reporting and CI/CD Integration

• Use Cypress built-in reporters or plugins like mochawesome for detailed HTML reports.
• Integrate Cypress tests in CI pipelines (GitHub Actions, Jenkins, GitLab CI) to run tests on every commit.
• Configure CI to run tests in isolated containers or environments to avoid shared state.
• Use screenshots and video recordings on test failures to help debug isolated test issues.

Best Practices for Test Isolation in Cypress

1. Reset State Between Tests: Use testIsolation: true and beforeEach() hooks to start each test fresh.
2. Avoid Shared State: Do not share variables or data between tests; use fixtures or fresh API calls.
3. Use Custom Commands: Encapsulate repetitive setup steps in cypress/support/commands.js to keep tests clean and isolated.
4. Clear Cookies and Local Storage: Use Cypress commands to clear browser data between tests if needed.
5. Run Tests in Parallel: Use Cypress Dashboard or CI parallelization to run isolated tests faster without interference.

Self Check

Where in this folder structure would you add a new custom command to reset the application state before each test?

Key Result

Use Cypress's built-in test isolation features combined with fixtures and custom commands to keep tests independent and reliable.