[Test] Add test cases for each endpoints.

[mavyfaby]

Currently, our project lacks sufficient test coverage for the different endpoints in our codebase. As we continue to build and modify the code, there is a chance of undetected defects and probable regressions. To increase the overall quality and stability of our service, we must add test cases for each endpoint.

To complete this task, please follow these steps:

• Identify all of our project's endpoints that do not yet include corresponding test cases.
• Create and execute test cases for each of these endpoints, taking into account various situations and edge cases.
• Create clear and simple test documentation to aid comprehension and maintainability.
• Incorporate the newly developed test cases into our current testing framework.
• Execute the test suite and ensure that all tests pass.
• If any problems or failures occur during testing, investigate and correct them.
• After adding and verifying all test cases, submit a pull request for review and merge.

CC: @TotalElderBerry @ampats04 @ReidoBoss @rmac3392 @MTonilon22