What is API Testing?
API is an acronym for Application Programming Interface. It allows the communication and exchange of data between two separate software systems. A software system that implements an API contains functions/subroutines that can be executed by another software system.
API Testing Approach
The quality assurance team performs API tests, which are a form of black box testing. This test is done after the construction is ready. The source code is not included in this test. In this test, a request is sent to the known API to analyze the response that includes:
- Return value based on the input condition – The return value of the API is checked based on the input condition
- Check that the API does not return anything
- Check that the API triggers some other event or calls another API. The event output must be tracked and checked
- Check that the API is updating any data structure.
API Testing Types?
The API test generally involves the following practices:
- Unit Testing: Test the functionality of individual operations.
- Functional Testing: To test the functionality of wider scenarios using the results of unit block tests tested together
- Load Testing: to test functionality and performance under load
- Runtime / Error Detection: To monitor an application to identify problems, such as exceptions and loss of resources
- Security Testing: to ensure that the implementation of the API is protected against external threats
- UI Testing: Runs as part of end-to-end integration testing to ensure that all aspects of the user interface work as expected
- Interoperability and WS compliance Testing: Interoperability and compliance testing of WS is A type of test that is applied to the SOAP APIs.
- Penetration Testing: to find vulnerabilities of an applicator that of invaders
- Fuzz Testing: to test the API forcing the entry into the system to try a forced accident
Types of bugs found in API testing
The following are the types of errors found:
- Duplicate or absent functionality
- Inappropriate messages
- Error handling mechanism is incompatible
- Multi-threaded problems
- Security, performance and security issues
- Reliability issues
The Benefits of API Testing
With the API test, after the logic is designed, tests can be created to validate the accuracy in the answers and the data. It is not necessary to wait for several teams to complete their work or for the full applications to be created – the test cases are isolated and prepared to be built immediately.
Easier Test Maintenance
UI is constantly changing and moving based on how they are accessed – browsers, devices, screen orientation, etc. This creates a nightmare scenario where tests are constantly being dispatched to accompany the actual code in production. API changes are much more controlled and less frequent – generally, API definition files, such as the OpenAPI Spec, can help make refactoring tests in just a few seconds of work.
Faster Time To Resolution
When the API tests fail, we know exactly where our system broke and where the defect can be found. This helps reduce the time for filtering errors between compilations, integrations and even different team members. The small and isolated footprint of an API test is perfect for faster MTTR statistics, a valuable KPI for DevOps teams.
Speed and Coverage of Testing
300 UI tests can take 30 hours to run. 300 API tests can be executed in 3 minutes. This means that you will find more errors in less time, in addition to correcting them immediately.