Before getting into what API testing is, it is essential to understand what an API is. An API (Application Programming Interface) indicates how two software programs should integrate with one another.
API (Application programming interfaces) testing is a kind of software testing that involves testing APIs directly and as part of integration testing and to determine if they meet the requirements of functionality, performance, security, and reliability. API testing is a form of Black Box testing and is conducted after the build is ready. The source code is not included here.
To test the APIs and the integrations, they enable a software system.
To perform API testing, a tool is required to structure and manage the test cases. Another requirement is full traceability of requirements and effective API documentation.
During API testing, certain bugs can be found. These bugs include:
- Duplicate or missing functionality
- Incompatibility of the error handling mechanism
- Reliability issues
- Security and performance issues
- Improper messaging
- Multi-threaded issues
The quality assurance team performs API testing. The testing is conducted after the build is ready. The source code will not be included here.
A request is sent to the API to analyze responses that include:
- Accuracy of data
- HTTP status code
- Error codes of any errors that are returned by API
- Results of non-functional tests like security and performance
- Response time
- Authorization checks
Use a test management tool that will help in API testing by letting you structure and categorize your test cases. The tool should also give you full requirements traceability along with high-level API documentation. During API testing, the following must be kept in mind:
- The API must be tested to check what happens and what does not happen on a consistent basis.
- Stress testing on the system must be performed through several API load tests.
- The API must be tested for failures. Test the API consistently so that it fails consistently.
- Group all the test cases by category.
- Mention all the parameters that are selected in the test case.
- Prioritize API function calls so that testing can be simplified and can be finished on time.
- Make plans to perform call sequencing.
- Create test cases for different and all API input combinations that are possible. This way, you can ensure that you get complete test coverage.
- Reuse the test cases and also monitor the API when in production.
- It depends on the manual and automated tests if you want better API testing outcomes.
API testing is a very important part of software quality assurance. With the right approach and the right tools, you can ensure it is carried out successfully. The more API testing is structured, the better will be the outcomes of the testing.