ABAP Unit Testing

Guide for writing effective ABAP Unit tests including test class setup, assertions, test doubles, mocking frameworks, and test environments for CDS, SQL, and RAP.

Workflow

1. Determine the testing goal:

   • Testing business logic in a class method
   • Testing a CDS view entity
   • Testing a RAP BO behavior implementation
   • Testing database-dependent logic with SQL test doubles
   • Setting up test doubles for external dependencies

2. Choose the right approach:

   • Direct unit test for pure logic (no dependencies)
   • Constructor/setter injection for mockable dependencies
   • CDS test environment for CDS view tests
   • OSQL test environment for SQL-dependent code
   • RAP BO test doubles for RAP behavior tests

3. Follow the AAA pattern: Arrange → Act → Assert

4. Ensure test isolation: Tests must not depend on persistent data or external systems

Test Class Fundamentals

Test Class Definition

"! Test class for ZCL_MY_CLASS
CLASS ltc_my_class DEFINITION FINAL FOR TESTING
  DURATION SHORT
  RISK LEVEL HARMLESS.

  PRIVATE SECTION.
    DATA cut TYPE REF TO zcl_my_class.  "Class Under Test

    CLASS-METHODS class_setup.    "Once before all tests
    CLASS-METHODS class_teardown. "Once after all tests
    METHODS setup.               "Before each test
    METHODS teardown.            "After each test

    METHODS test_calculate_total FOR TESTING.
    METHODS test_validate_input  FOR TESTING.
    METHODS test_empty_input     FOR TESTING RAISING cx_static_check.
ENDCLASS.

CLASS ltc_my_class IMPLEMENTATION.

  METHOD class_setup.
    " One-time setup for all tests in this class
  ENDMETHOD.

  METHOD class_teardown.
    " One-time cleanup
  ENDMETHOD.

  METHOD setup.
    " Create fresh instance before each test
    cut = NEW #( ).
  ENDMETHOD.

  METHOD teardown.
    " Cleanup after each test
  ENDMETHOD.

  METHOD test_calculate_total.
    " Arrange
    DATA(lv_quantity) = 5.
    DATA(lv_price) = CONV decfloat34( '10.50' ).

    " Act
    DATA(lv_result) = cut->calculate_total(
      iv_quantity = lv_quantity
      iv_price    = lv_price ).

    " Assert
    cl_abap_unit_assert=>assert_equals(
      act = lv_result
      exp = CONV decfloat34( '52.50' )
      msg = 'Total should be quantity * price' ).
  ENDMETHOD.

  METHOD test_validate_input.
    cl_abap_unit_assert=>assert_true(
      act = cut->validate_input( 'VALID_INPUT' )
      msg = 'Valid input should return true' ).
  ENDMETHOD.

  METHOD test_empty_input.
    TRY.
        cut->validate_input( '' ).
        cl_abap_unit_assert=>fail( msg = 'Should have raised exception' ).
      CATCH zcx_validation_error INTO DATA(lx_error).
        cl_abap_unit_assert=>assert_bound(
          act = lx_error
          msg = 'Exception should be raised for empty input' ).
    ENDTRY.
  ENDMETHOD.

ENDCLASS.

Test Class Attributes

Attribute	Options	Purpose
DURATION	SHORT / MEDIUM / LONG	Expected execution time; SHORT < 1s (default for CI)
RISK LEVEL	HARMLESS / DANGEROUS / CRITICAL	Impact on system data; HARMLESS = no DB changes

Test Method Additions

Addition	Purpose
FOR TESTING	Marks method as a test method
RAISING cx_static_check	Allows exceptions to propagate (test fails on unhandled exception)

CL_ABAP_UNIT_ASSERT — Assertion Methods

Method	Purpose	Example
assert_equals	Value equality	assert_equals( act = result exp = 42 )
assert_true	Boolean true	assert_true( act = lv_flag )
assert_false	Boolean false	assert_false( act = lv_flag )
assert_initial	Value is initial	assert_initial( act = lt_table )
assert_not_initial	Value is not initial	assert_not_initial( act = lt_result )
assert_bound	Reference is bound	assert_bound( act = lo_instance )
assert_not_bound	Reference is not bound	assert_not_bound( act = lo_ref )
assert_differs	Values are different	assert_differs( act = val1 exp = val2 )
assert_char_cp	Character pattern match	assert_char_cp( act = lv_text exp = '*error*' )
assert_char_np	Character pattern no match	assert_char_np( act = lv_text exp = '*secret*' )
assert_number_between	Number in range	assert_number_between( number = val lower = 1 upper = 10 )
assert_table_contains	Table contains line	assert_table_contains( line = wa table = lt_result )
assert_table_not_contains	Table does not contain line	assert_table_not_contains( line = wa table = lt_result )
assert_return_code	sy-subrc check	assert_return_code( act = sy-subrc exp = 0 )
fail	Force test failure	fail( msg = 'Should not reach here' )

Common Assertion Patterns

" Check table has expected number of entries
cl_abap_unit_assert=>assert_equals(
  act = lines( lt_result )
  exp = 3
  msg = 'Expected 3 result entries' ).

" Check exception message
TRY.
    cut->some_method( ).
    cl_abap_unit_assert=>fail( msg = 'Expected exception' ).
  CATCH zcx_my_exception INTO DATA(lx).
    cl_abap_unit_assert=>assert_equals(
      act = lx->get_text( )
      exp = 'Expected error message' ).
ENDTRY.

" Check that table contains a specific key
cl_abap_unit_assert=>assert_table_contains(
  line  = VALUE zstructure( key_field = 'ABC' )
  table = lt_result
  msg   = 'Result should contain entry ABC' ).

Dependency Injection & Test Doubles

Constructor Injection Pattern

" Production interface
INTERFACE zif_data_provider.
  METHODS get_data
    RETURNING VALUE(rt_data) TYPE ztab_data.
ENDINTERFACE.

" Production class with injectable dependency
CLASS zcl_processor DEFINITION.
  PUBLIC SECTION.
    METHODS constructor
      IMPORTING io_provider TYPE REF TO zif_data_provider OPTIONAL.
    METHODS process
      RETURNING VALUE(rv_result) TYPE string.
  PRIVATE SECTION.
    DATA mo_provider TYPE REF TO zif_data_provider.
ENDCLASS.

CLASS zcl_processor IMPLEMENTATION.
  METHOD constructor.
    mo_provider = COND #(
      WHEN io_provider IS BOUND THEN io_provider
      ELSE NEW zcl_default_provider( ) ).
  ENDMETHOD.

  METHOD process.
    DATA(lt_data) = mo_provider->get_data( ).
    " Process data...
  ENDMETHOD.
ENDCLASS.

Test Double (Manual Mock)

" Test double implementing the interface
CLASS ltd_data_provider DEFINITION FOR TESTING.
  PUBLIC SECTION.
    INTERFACES zif_data_provider.
    DATA mt_test_data TYPE ztab_data.
ENDCLASS.

CLASS ltd_data_provider IMPLEMENTATION.
  METHOD zif_data_provider~get_data.
    rt_data = mt_test_data.
  ENDMETHOD.
ENDCLASS.

" Test class using the double
CLASS ltc_processor DEFINITION FINAL FOR TESTING
  DURATION SHORT RISK LEVEL HARMLESS.
  PRIVATE SECTION.
    DATA cut        TYPE REF TO zcl_processor.
    DATA mo_provider TYPE REF TO ltd_data_provider.

    METHODS setup.
    METHODS test_process_with_data FOR TESTING.
ENDCLASS.

CLASS ltc_processor IMPLEMENTATION.
  METHOD setup.
    mo_provider = NEW #( ).
    cut = NEW #( io_provider = mo_provider ).
  ENDMETHOD.

  METHOD test_process_with_data.
    " Arrange — configure test double
    mo_provider->mt_test_data = VALUE #(
      ( key = '1' value = 'A' )
      ( key = '2' value = 'B' ) ).

    " Act
    DATA(lv_result) = cut->process( ).

    " Assert
    cl_abap_unit_assert=>assert_not_initial( act = lv_result ).
  ENDMETHOD.
ENDCLASS.

CDS Test Environment

Use cl_cds_test_environment=>create( i_for_entity = 'ZI_ENTITY' ) to stub all data sources of a CDS view. Insert test data with insert_test_data( ), clear with clear_doubles( ) in setup, and call destroy( ) in class_teardown.

OSQL (Open SQL) Test Environment

Use cl_osql_test_environment=>create( i_dependency_list = ... ) to stub specific DB tables/views for testing SQL-dependent classes. Same lifecycle pattern as CDS test environment.

RAP BO Test Doubles

• Transactional buffer double (cl_botd_txbufdbl_bo_test_env): For testing code that consumes a RAP BO via EML
• Mock EML API (cl_botd_mockemlapi_bo_test_env): For testing RAP handler method implementations by configuring mock responses

Test Seams (Legacy Code)

Use TEST-SEAM / END-TEST-SEAM in production code and TEST-INJECTION / END-TEST-INJECTION in tests. Prefer constructor injection for new code.

For full code examples of all the above, read references/test-environment-examples.md.

Best Practices

Test Design

• One assertion concept per test — each test should verify one behavior
• Descriptive test method names — test_reject_negative_quantity not test_1
• Independent tests — no test should depend on another test's outcome or execution order
• Fast tests — use DURATION SHORT and avoid unnecessary setup

Test Isolation

• Always use test doubles for external dependencies (DB, APIs, other BOs)
• Use setup / teardown to ensure clean state
• Use class_setup / class_teardown for expensive one-time setup (test environments)
• Always call clear_doubles( ) in setup for test environment classes
• Always call destroy( ) in class_teardown

Test Structure

• Place test classes in local test include (test classes tab in ADT)
• Prefix test doubles with ltd_ (local test double)
• Prefix test classes with ltc_ (local test class)
• Group related tests in the same test class

What to Test

• Business logic and calculations
• Validation rules and error cases
• Edge cases (empty input, boundary values, null references)
• CDS view calculations and aggregations
• RAP handler logic (actions, validations, determinations)

What Not to Test

• Framework-provided functionality (managed CRUD in RAP)
• Simple getter/setter methods
• ABAP runtime behavior

References

• SAP ABAP Cheat Sheets — ABAP Unit Tests
• SAP Help — ABAP Unit
• SAP Help — CDS Test Double Framework
• SAP Help — RAP BO Test Doubles
• Clean ABAP — Testing