CMake: comment on BUILD_AS_TEST

CMakeModules/CalamaresAddTest.cmake

@@ -42,6 +42,8 @@ function( calamares_add_test )
                 Qt5::Test
             )
         calamares_automoc( ${TEST_NAME} )
+        # We specifically pass in the source directory of the test-being-
+        # compiled, so that it can find test-files in that source dir.
         target_compile_definitions( ${TEST_NAME} PRIVATE -DBUILD_AS_TEST="${CMAKE_CURRENT_SOURCE_DIR}"  ${TEST_DEFINITIONS} )
         if( TEST_GUI )
             target_link_libraries( ${TEST_NAME} calamaresui Qt5::Gui )

src/modules/users/Tests.cpp

@@ -196,6 +196,7 @@ UserTests::testDefaultGroupsYAML()
     QFETCH( int, count );
     QFETCH( QString, group );
 
+    // BUILD_AS_TEST is the source-directory path
     QFile fi( QString( "%1/%2" ).arg( BUILD_AS_TEST, filename ) );
     QVERIFY( fi.exists() );