How To Fix ABAP_TESTDOUBLE037 - &4 Double cannot be created if all methods in a class are STATIC

SAP Error Message - Details

• Message type: E = Error

• Message class: ABAP_TESTDOUBLE -

• Message number: 037

• Message text: &4 Double cannot be created if all methods in a class are STATIC

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

Unfortunately, there isn't any extra information in this error notice.

What else can you do?

First, use our AnswerBot below to get a possible cause and solution (requires a premium subscription).

Also, review the in-depth Common Questions & Answers listed below; you could discover a solution there or be able to connect with others who have faced similar challenges.

You can also try searching the SAP support portal (support.sap.com) but you need a special user ID to access it. It is possible that an SAP support note exists that provides additional details about the mistake or even steps for fixing it.

Smart SAP Assistant

• What is the cause and solution for SAP error message ABAP_TESTDOUBLE037 - &4 Double cannot be created if all methods in a class are STATIC ?

  The SAP error message ABAP_TESTDOUBLE037 indicates that you are trying to create a test double (a mock or stub) for a class in ABAP, but the class in question has all its methods defined as static. In ABAP, a test double is typically used in unit tests to simulate the behavior of a class or its methods without invoking the actual implementation.
  Cause:
  The error occurs because:
  
  A test double cannot be created for a class that has only static methods. Test doubles are designed to work with instance methods, as they rely on the ability to instantiate an object of the class.
  Static methods belong to the class itself rather than to any instance of the class, which makes it impossible to create a test double that can override or simulate the behavior of those methods.
  
  Solution:
  To resolve this error, you have a few options:
  
  
  Refactor the Class:
  
  If possible, refactor the class to include instance methods instead of only static methods. This allows you to create instances of the class and subsequently create test doubles for those instances.
  
  
  
  Use Static Method Testing:
  
  If the methods must remain static, consider testing them directly without using test doubles. You can call the static methods in your unit tests and verify their behavior based on the expected outcomes.
  
  
  
  Create a Wrapper Class:
  
  If you need to maintain the static methods for some reason, you could create a wrapper class that contains instance methods that call the static methods. You can then create test doubles for this wrapper class.
  
  
  
  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 desired behavior. This way, you can mock or stub the behavior in your tests.
  
  
  
  Related Information:
  
  Unit Testing in ABAP: Familiarize yourself with the ABAP Unit Testing framework, which provides tools for writing and executing unit tests.
  Mocking Frameworks: Explore available mocking frameworks in ABAP that can help you create test doubles for classes with instance methods.
  Best Practices: Follow best practices for designing classes in ABAP, such as favoring instance methods when you anticipate the need for testing and mocking.
  
  By addressing the structure of your class and how you intend to test it, you can resolve the ABAP_TESTDOUBLE037 error and improve the testability of your code.