API Testing : Using Cypress

Here is a comprehensive tutorial for API Testing Using Cypress, designed to help you master API automation testing with this powerful tool.

Overview

Cypress is not just for end-to-end UI testing; it’s a robust framework for testing APIs efficiently. With built-in capabilities to send HTTP requests and validate responses, Cypress makes API testing fast, reliable, and easy.

Setup for API Testing

1?? Install Cypress

1. Make sure Node.js is installed on your system.
2. Initialize a new project:
3. Install Cypress:

2?? Launch Cypress

1. Open Cypress:
2. Create a new test file for API tests under cypress/e2e.

Key Features of Cypress for API Testing

• cy.request(): To send HTTP requests (GET, POST, PUT, DELETE).
• Assertions: Validate response status, headers, and body.
• Integration: Seamlessly combine API and UI testing.

Step-by-Step Guide to API Testing with Cypress

1?? Sending GET Requests

Retrieve data from an API and validate the response.

2?? Sending POST Requests

Submit data to an API and validate the response.

3?? Sending PUT Requests

Update existing data.

4?? Sending DELETE Requests

Remove data from the API.

Advanced Concepts

1?? Validating Response Headers

it('Validate Response Headers', () => {
  cy.request('GET', 'https://jsonplaceholder.typicode.com/posts/1')
    .then((response) => {
      expect(response.headers).to.have.property('content-type', 'application/json; charset=utf-8');
    });
});        

2?? Extracting and Using Data

Store and reuse data in subsequent requests.

3?? Handling Authentication

Using Bearer Token

4?? Testing Error Scenarios

Validate the behaviour for invalid inputs or permissions.

Best Practices for API Testing with Cypress

1. Organize Tests: Use meaningful test descriptions and group related tests using describe.
2. Use Custom Commands: Define reusable logic in commands.js.
3. Data-Driven Testing: Load test data dynamically using fixtures.
4. Integrate with CI/CD: Run Cypress tests in CI pipelines for continuous validation.
5. Logging and Reporting: Integrate Cypress plugins for better test reporting (e.g., Mochawesome).

Combining API and UI Testing

Cypress allows seamless integration of API calls within UI tests.

Conclusion

API testing with Cypress is straightforward and powerful. By leveraging its features, you can:

? Automate complex API scenarios.

? Validate APIs alongside UI flows.

? Ensure reliable and robust test coverage.

Start with the basics, practice real-world scenarios, and integrate Cypress into your testing toolkit to become an API testing expert!

Happy Learning!