COMP: Fix setting module paths associated with slicer_add_python test…

…ing macros

This commit is a follow-up of f07a6c3 (BUG: Teach 'slicer_add_python_unittest'
to add module search paths).

It ensures that arguments like "--disable-modules", "--disable-*-modules",
"--disable-builtin-modules" or "--disable-builtin-*-modules" that are
associated with SLICER_ARGS works as expected when running Slicer built-in
tests.

CMake/SlicerMacroPythonTesting.cmake

@@ -34,13 +34,15 @@ macro(slicer_add_python_test)
   if(NOT IS_ABSOLUTE ${MY_SCRIPT})
     set(MY_SCRIPT "${CMAKE_CURRENT_SOURCE_DIR}/${MY_SCRIPT}")
   endif()
+  if(NOT Slicer_SOURCE_DIR)
+    list(APPEND MY_SLICER_ARGS ${UNITTEST_LIB_PATHS})
+  endif()
   ExternalData_add_test(${Slicer_ExternalData_DATA_MANAGEMENT_TARGET}
     NAME py_${MY_TESTNAME_PREFIX}${test_name}
     COMMAND ${Slicer_LAUNCHER_EXECUTABLE}
     --no-splash
     --testing
     ${Slicer_ADDITIONAL_LAUNCHER_SETTINGS}
-    ${UNITTEST_LIB_PATHS}
     ${MY_SLICER_ARGS}
     --python-script ${MY_SCRIPT} ${MY_SCRIPT_ARGS}
     )
@@ -57,14 +59,16 @@ macro(slicer_add_python_unittest)
   if("${_script_source_dir}" STREQUAL "")
     set(_script_source_dir ${CMAKE_CURRENT_SOURCE_DIR})
   endif()
+  if(NOT Slicer_SOURCE_DIR)
+    list(APPEND MY_SLICER_ARGS ${UNITTEST_LIB_PATHS})
+  endif()
   ExternalData_add_test(${Slicer_ExternalData_DATA_MANAGEMENT_TARGET}
     NAME py_${MY_TESTNAME_PREFIX}${test_name}
     COMMAND ${Slicer_LAUNCHER_EXECUTABLE}
     --no-splash
     --testing
     ${Slicer_ADDITIONAL_LAUNCHER_SETTINGS}
     ${MY_SLICER_ARGS}
-    ${UNITTEST_LIB_PATHS}
     --python-code "import slicer.testing\\; slicer.testing.runUnitTest(['${CMAKE_CURRENT_BINARY_DIR}', '${_script_source_dir}'], '${test_name}')"
     )
   set_property(TEST py_${MY_TESTNAME_PREFIX}${test_name} PROPERTY RUN_SERIAL TRUE)