unit-test-exception-handler

To test Spring Boot exception handling with MockMvc, you simulate HTTP requests that trigger exceptions and assert the resulting HTTP status codes and error response formatting. This validates that @ExceptionHandler and @ControllerAdvice implementations catch and map errors correctly.

Verifying a custom business exception returns the correct HTTP status code in JUnit 5 involves triggering the exception via a MockMvc request and asserting the response status. This confirms your global exception handler accurately maps specific exceptions to expected HTTP statuses like 404 or 400.

Validating @ControllerAdvice error response formatting is best done by checking the structure and content of error responses via MockMvc. This ensures that caught exceptions produce consistent and informative error messages across your Spring Boot application.

You can test validation errors and resource not found scenarios using Spring Boot MockMvc by making requests that trigger these conditions. This allows you to assert that your global exception handling returns appropriate HTTP status codes like 400 for bad requests and 404 for not found.

If your Spring Boot @ControllerAdvice does not return the expected error response structure, testing with MockMvc and JUnit 5 helps identify the mapping mismatch. Asserting response content confirms whether your @ExceptionHandler correctly formats the error output.