As with any code you write, you want to test your API to ensure that requests are processed as you expect, the responses sent are correct, and the operations performed on the database are correct and persist.
Why Test an API?
As with all tests, writing unittests for your API verifies the behavior. For APIs, test should be written:
In addition to verifying behavior, having a thorough test suite ensures that when you update your API, you can easily test all previous functionality.
If bugs are discovered while in development, they cost next to nothing to fix and don’t have any negative impact on business outcomes or client experience. But if bugs make it to production, their cost can be quite large - they can impact performance, and fixing bugs can take large amounts of time for big, production applications.
The order of operations for app development should always be:
Step 2 is essential to ensuring the application is production-ready and time-to-production is used efficiently.