API testing is crucial for verifying functionality, ensuring performance, identifying security vulnerabilities, and facilitating integration with other systems. It typically involves using tools like pytest for executing test cases on API endpoints through various HTTP requests, while also supporting multiple testing types including unit, integration, and load testing. Although pytest offers advantages like fast execution and powerful assertions, it has limitations such as a learning curve for advanced features and a focus exclusively on backend testing.

1. API TESTING
USING PYTEST

3. Why We Need API Testing:
• Verify functionality: Ensure API behaves as expected.
• Performance & load testing: Check how well the API handles high traffic.
• Security: Identify vulnerabilities in the API.
• Integration testing: Ensure smooth interaction with other services or systems.

4. How API Testing Works:
• API testing focuses on ensuring that the API endpoints work as expected.
• Pytest is a Python testing framework used to write and execute test cases for
APIs.
• You can send HTTP requests (GET, POST, PUT, DELETE) to API endpoints using
libraries like requests.
• Assertions in pytest verify the expected response, such as status codes,
response times, and response content.

9. Common Tools for API Testing:
• Postman: A popular GUI tool for sending HTTP requests to an API and viewing the responses.
• SoapUI: A tool for testing both RESTful and SOAP APIs with a strong focus on enterprise-level
needs.
• Rest Assured: A Java-based library for testing REST APIs, widely used in automation scripts.
• Pytest: A Python framework for testing APIs, often used in combination with libraries like
requests for sending HTTP requests.

10. Common API Testing Types:
• Unit Testing: Testing individual functions or methods within the API to ensure
they behave correctly in isolation.
• Integration Testing: Testing how the API interacts with other components or
systems, such as databases or third-party services.
• Load Testing: Testing the API's performance under heavy traffic or multiple
requests.
• Security Testing: Ensuring that the API is resistant to unauthorized access, SQL
injection, cross-site scripting (XSS), etc.

11. Advantages of API Testing with
Pytest
•Fast Execution: Runs tests quickly, identifying issues early.
•Powerful Assertions: Built-in methods make validating API responses easy
and clear.
•Highly Extensible: Supports plugins and custom fixtures for added
functionality.
•Parallel Testing: Runs multiple tests simultaneously with tools like pytest-
xdist.
•Seamless CI/CD Integration: Fits well into automated deployment pipelines.
•Detailed Reporting: Provides comprehensive logs to simplify debugging.

12. Disadvantages of API Testing with
Pytest
•Basic Features: Requires additional libraries for API-specific testing.
•Learning Curve: Advanced features can be tricky for beginners.
•Not for UI Testing: Focuses only on backend testing.
•Test Maintenance: Updating tests for API changes can be time-consuming.
•Complex Authentication: Needs extra setup for handling advanced security
methods.