Questions and Suggestions Regarding CAP Java Testing Documentation

[ziyang-works]

Hi, I've recently started working with CAP Java and have some questions about the Testing documentation. I hope to get some clarification here or possibly see these addressed in a future update to the documentation.

The current documentation categorizes testing into three types:

1. Event Handler Layer Testing
2. Service Layer Testing
3. Integration Testing

Use Case

I have the following files:

• UserImportService.cds: A CDS service file providing a custom action import for bulk user creation.
• UserImportHandler.cds: A service handler file implementing the custom action logic.

I need to test the following scenarios:

• Case 1: Validate HTTP response codes:
  • Correct JSON request → HTTP 2xx
  • Invalid JSON/missing auth → Corresponding 4xx
• Case 2: Handle invalid request bodies:
  • Missing fields or invalid types → Expected exception and no database entries
• Case 3: Verify field mapping:
  • Ensure input fields are correctly mapped to output values using the service handler’s mapper classes.
• Case 4: Ensure transactional integrity:
  • If one user creation fails, no users should be created in the database.

Current Testing Approach

To cover the above scenarios, I currently employ the following three testing types:

1. Unit Tests (...MapperTest.java)
   • Test mapping logic for Case 3 using mocks.
2. Service Layer Tests (UserImportServiceTest.java with @SpringBootTest)
   • Validate business logic for Case 2 and Case 4 with Java entity objects as request body
3. Integration Tests (UserImportServiceITest.java with @SpringBootTest)
   • Test end-to-end HTTP calls for Case 1 with JSON request body

Challenges and Questions

1. Overlapping Tests:

   • Service Layer Tests and Integration Tests have overlaps (although Service Layer Tests include many more edge cases). Is there a best practice for distinguishing these types of tests?

2. Naming Confusion:

   • File names like UserImportServiceTest.java and UserImportServiceITest.java can confuse future developers about where to add new tests. Could you suggest clearer naming conventions?

3. Terminology in Documentation:

   • Why does the documentation refer to Service Layer test files as ...ServiceTest.java when the default handler files are named ...Handler.java? This could be confusing, especially in projects where a ...Service.java file might exist for additional business logic.

4. Performance vs. Mocking:

   • Tests with @SpringBootTest are slower than unit tests with mocks. However, heavy mocking can make the test code complex. What is the recommended balance between these approaches?

5. Example Projects:

   • Is there a large CAP example project demonstrating these three testing types in a structured way?

Thank you for your time! I look forward to your insights and suggestions.

[renejeglinsky]

Hi @ziyang-works ,

thanks a lot for opening this issue. I'm on it to find an expert for those topics. We'll get back to you.

Thanks René