How To Fix CDS_UNIT_MESSAGE028 - Unit testing of &1 is not possible.

SAP Error Message - Details

• Message type: E = Error

• Message class: CDS_UNIT_MESSAGE - Message Class

• Message number: 028

• Message text: Unit testing of &1 is not possible.

Because test double creation is not possible for &V2& as &V3& testing of
&V4& already involves &V2&.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message CDS_UNIT_MESSAGE028 - Unit testing of &1 is not possible. ?

  The SAP error message CDS_UNIT_MESSAGE028 indicates that unit testing for a Core Data Services (CDS) view or entity is not possible. This error typically arises when there are issues with the configuration or definition of the CDS view that prevent it from being tested.
  Causes:
  
  Missing Annotations: The CDS view may lack the necessary annotations that are required for unit testing.
  Incompatible Data Model: The data model used in the CDS view may not be compatible with unit testing.
  Incorrect Implementation: There may be issues in the implementation of the CDS view, such as syntax errors or logical errors.
  Dependencies: The CDS view might depend on other views or tables that are not available or not properly defined.
  Transport Issues: If the CDS view is in a transport request that has not been released or imported into the testing environment, it may not be testable.
  
  Solutions:
  
  
  Check Annotations: Ensure that the CDS view has the necessary annotations for unit testing. You may need to add the @Testable annotation to the CDS view definition.
  Example:
  @AbapCatalog.sqlViewName: 'Z_MY_CDS_VIEW'
  @Testable: true
  define view Z_MY_CDS_VIEW as select from my_table
  {
      key field1,
      field2
  }
  
  
  Review the Data Model: Verify that the data model used in the CDS view is correctly defined and does not have any inconsistencies.
  
  
  Debug the Implementation: Check the implementation of the CDS view for any syntax or logical errors. Use the ABAP Development Tools (ADT) to debug and analyze the view.
  
  
  Check Dependencies: Ensure that all dependent views and tables are available and correctly defined in the system.
  
  
  Transport Management: If the CDS view is part of a transport request, ensure that the transport has been released and imported into the appropriate environment.
  
  
  Consult Documentation: Refer to the SAP documentation for any specific requirements or limitations related to unit testing of CDS views.
  
  
  Related Information:
  
  SAP Notes: Check for any relevant SAP Notes that may address known issues or provide additional guidance on unit testing CDS views.
  SAP Community: Engage with the SAP Community forums to see if other users have encountered similar issues and what solutions they found effective.
  ABAP Development Tools: Utilize the features in ABAP Development Tools for better debugging and analysis of CDS views.
  
  By following these steps, you should be able to identify the cause of the error and implement a solution to enable unit testing for your CDS view.