How to do API testing manually?

Manual API Testing: A Comprehensive Guide

API testing plays a crucial role in ensuring the reliability and functionality of software applications. While automated testing offers efficiency and speed, manual API testing remains invaluable for addressing specific scenarios and exploring edge cases. This article provides a detailed guide on how to perform manual API testing effectively.

1. Planning and Preparation

Before initiating manual API testing, it is essential to gather necessary information, including:

• API documentation detailing endpoints, request formats, and expected responses
• Test cases covering different scenarios and edge cases
• Test data to simulate real-world usage

2. Setting Up the Test Environment

Configure the test environment to replicate the production setup as closely as possible. This includes:

• Setting up a server to host the API under test
• Installing dependencies and configuring any necessary software
• Ensuring network connectivity and stability

3. Sending API Requests

Manually send API requests using tools such as command-line clients (e.g., cURL) or browser extensions (e.g., Postman). Carefully craft requests according to the API documentation and test cases.

4. Verifying Server Status Codes

Examine the HTTP status codes returned by the server to determine the success or failure of the request. Ensure that the status codes match the expected behaviors defined in the API documentation.

5. Measuring Response Times

Measure the time it takes for the server to respond to requests. This is crucial for performance testing and ensuring that the API meets performance benchmarks.

6. Validating Data Format

Verify that the response data is formatted correctly according to the pre-defined JSON schema. Use tools such as JSON validators or schema checkers to ensure data integrity and consistency.

7. Exploring Edge Cases

Execute test cases that explore edge cases, such as:

• Sending malformed requests
• Testing with empty or invalid data
• Simulating high traffic scenarios

8. Documenting Test Results

Document the results of each test case, including the request, response, and any observations or issues encountered. This documentation serves as a valuable resource for debugging and future reference.

Conclusion

Manual API testing remains an effective and thorough method for ensuring the correctness and reliability of APIs. By following the steps outlined in this guide, testers can manually verify expected behaviors, measure response times, validate data formats, and explore edge cases. This comprehensive approach helps uncover issues that may be missed by automated tests, ultimately contributing to the overall quality and reliability of software applications.