How To Fix ABAP_TESTDOUBLE028 - &4 Illegal configuration for &1. Static methods not supported

SAP Error Message - Details

• Message type: E = Error

• Message class: ABAP_TESTDOUBLE -

• Message number: 028

• Message text: &4 Illegal configuration for &1. Static methods not supported

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message ABAP_TESTDOUBLE028 - &4 Illegal configuration for &1. Static methods not supported ?

  The SAP error message ABAP_TESTDOUBLE028 indicates that there is an illegal configuration for a specific object, and it specifically mentions that static methods are not supported. This error typically arises in the context of unit testing in ABAP, particularly when using test doubles (mocks or stubs) in your tests.
  Cause:
  The error occurs when you attempt to create a test double (like a mock or stub) for a class that contains static methods. In ABAP, the test double framework does not support mocking or stubbing static methods because they are not tied to an instance of a class. This limitation is inherent to the way static methods are designed in object-oriented programming, as they belong to the class itself rather than to any instance of the class.
  Solution:
  To resolve this error, you can consider the following approaches:
  
  
  Refactor the Code: If possible, refactor the code to avoid using static methods. Instead, use instance methods that can be mocked or stubbed. This may involve creating an instance of the class and calling its methods rather than relying on static methods.
  
  
  Use Dependency Injection: If the static methods are part of a utility class, consider using dependency injection to pass an instance of a class that implements the required functionality. This way, you can mock the instance in your tests.
  
  
  Create Wrapper Classes: If refactoring is not feasible, you can create a wrapper class around the static methods. This wrapper can be instantiated and can delegate calls to the static methods. You can then mock the wrapper class in your tests.
  
  
  Avoid Testing Static Methods: If the static methods are utility functions that do not have side effects, you might consider not testing them directly. Instead, focus on testing the classes that use these static methods.
  
  
  Related Information:
  
  Unit Testing in ABAP: Familiarize yourself with the principles of unit testing in ABAP, including how to use the ABAP Unit framework effectively.
  Test Doubles: Understand the concept of test doubles, including mocks, stubs, and fakes, and how they can be used to isolate the unit of work being tested.
  Static Methods in ABAP: Review the implications of using static methods in ABAP and how they differ from instance methods, especially in the context of testing.
  
  By following these approaches, you should be able to resolve the ABAP_TESTDOUBLE028 error and improve the testability of your ABAP code.