build: do not build the test object library when tests are disabled

build-support/macros-and-definitions.cmake

@@ -410,6 +410,8 @@ macro(process_options)
   if(${NS3_TESTS} OR ${ns3rc_tests_enabled})
     set(ENABLE_TESTS ON)
     enable_testing()
+  else()
+    list(REMOVE_ITEM libs_to_build test)
   endif()
 
   set(profiles_without_suffixes release)
@@ -1929,10 +1931,6 @@ macro(
       unset(dependencies)
       unset(contrib_dependencies)
     endforeach()
-
-    if(core IN_LIST ${libs_to_build})
-      list(APPEND ${libs_to_build} test) # include test module
-    endif()
   endif()
 
   if(${NS3_DISABLED_MODULES} OR ${ns3rc_disabled_modules})

utils/tests/test-ns3.py

@@ -970,7 +970,7 @@ class NS3ConfigureTestCase(NS3BaseTestCase):
             self.assertLess(len(get_enabled_modules()), len(self.ns3_modules))
             self.assertIn("ns3-lte", enabled_modules)
             self.assertTrue(get_test_enabled())
-            self.assertGreaterEqual(len(get_programs_list()), len(self.ns3_executables))
+            self.assertLessEqual(len(get_programs_list()), len(self.ns3_executables))
 
             # Replace the ns3rc file with the wifi module, enabling examples and disabling tests
             with open(ns3rc_script, "w") as f:
@@ -1839,6 +1839,21 @@ class NS3ConfigureTestCase(NS3BaseTestCase):
             except DockerException as e:
                 self.assertTrue(False, "Precompiled headers should have been enabled")
 
+    def test_24_CheckTestSettings(self):
+        """!
+        Check for regressions in test object build.
+        @return None
+        """
+        return_code, stdout, stderr = run_ns3('configure')
+        self.assertEqual(return_code, 0)
+
+        test_module_cache = os.path.join(ns3_path, "cmake-cache", "src", "test")
+        self.assertFalse(os.path.exists(test_module_cache))
+
+        return_code, stdout, stderr = run_ns3('configure --enable-tests')
+        self.assertEqual(return_code, 0)
+        self.assertTrue(os.path.exists(test_module_cache))
+
 
 class NS3BuildBaseTestCase(NS3BaseTestCase):
     """!