What is an API ?
API is the Application Program Interface that allows the computer or application to talk or communicate with another one.
In other words, it allows transmitting the data between two separate application products.
What is API Testing?
API testing is a type of software testing which tests API directly. The motive of the API testing is to test the performance, functionality, reliability, and the security of application.
In API Testing users use software to send calls to the API, get output, and note down the system’s response. GUI Tests are very different from API tests. API tests focus primarily on the business logic layer of software architecture.
Why API Testing?
- API Testing helps to find small issues.
- API Testing is fast and hence users can test applications in lesser time.
- API testing helps to find the issues like missing or duplicate functionality.
- API testing can provide security for application
- API testing having high performance speed.
Types of API Testing :-
1. Validation Testing:
Validation testing comes in the final stages and plays an important role in the development process. It verifies the aspects of behaviour, product, and efficiency
2. Functional Testing:
This includes testing of specific functions in the codebase.
These tasks represent specific situations to ensure that the API works within the expected parameters and handles errors.
3. UI Testing:
The UI test is defined as a test of the user interface for your API and its integral parts. The UI test focuses more on the interface that connects to the API rather than the API test.
4. Load Testing:
Load testing usually occurs after the compilation of a specific unit or entire codebase. It checks whether the theoretical solution works as planned.
5. Runtime Or Error Detection:
These types of tests are entirely related to the actual running of the API, Most of our tastes are primarily related to the API and the outcome of the implementation of the environment or scenarios. This mainly focuses on monitoring, executing error, and error detection.
6. Security Testing:
To ensure that API implementation is protected from external threats, This test includes additional steps such as the validity of the encryption, its functionality, and the design of the API access control.
Challenges Of API Testing:
- The main challenges in Web API testing are Parameter Combination, Parameter Selection, and Call Sequencing
- There is no GUI available to test the application which makes it difficult to give input values
- Tester must know about the parameters selection and category is required
- Exception handling function needs to be tested
- Coding knowledge is necessary for testers
Advantages of API Testing:
- Users can access applications without a UI.
- Users can test the core functionality of the application
- It is time effective
- It is language independent
- It will easily integrate with GUI
API consists of a set of classes/functions/procedures which represent the business logic layer. If API is not tested properly, it may cause problems not only the API application but also in the calling application