making sure the issue comes from GDUnit addon folder

addons/gdUnit4/src/core/GdUnitTestResourceLoader.gd

@@ -0,0 +1,97 @@
+class_name GdUnitTestResourceLoader
+extends RefCounted
+
+const GdUnitTools := preload("res://addons/gdUnit4/src/core/GdUnitTools.gd")
+
+enum {
+	GD_SUITE,
+	CS_SUITE
+}
+
+
+static func load_test_suite(resource_path: String, script_type := GD_SUITE) -> Node:
+	match script_type:
+		GD_SUITE:
+			return load_test_suite_gd(resource_path)
+		CS_SUITE:
+			return load_test_suite_cs(resource_path)
+	assert("type '%s' is not implemented" % script_type)
+	return null
+
+
+static func load_tests(resource_path: String) -> Dictionary:
+	var script := load_gd_script(resource_path)
+	var discovered_tests := {}
+	GdUnitTestDiscoverer.discover_tests(script, func(test: GdUnitTestCase) -> void:
+		discovered_tests[test.display_name] = test
+	)
+
+	return discovered_tests
+
+
+static func load_test_suite_gd(resource_path: String) -> GdUnitTestSuite:
+	var script := load_gd_script(resource_path)
+	var discovered_tests: Array[GdUnitTestCase] = []
+	GdUnitTestDiscoverer.discover_tests(script, func(test: GdUnitTestCase) -> void:
+		discovered_tests.append(test)
+	)
+	# complete test suite wiht parsed test cases
+	return GdUnitTestSuiteScanner.new().load_suite(script, discovered_tests)
+
+
+static func load_test_suite_cs(resource_path: String) -> Node:
+	if not GdUnit4CSharpApiLoader.is_api_loaded():
+		return null
+	var script :Script = ClassDB.instantiate("CSharpScript")
+	script.source_code = GdUnitFileAccess.resource_as_string(resource_path)
+	script.resource_path = resource_path
+	script.reload()
+	return null
+
+
+static func load_cs_script(resource_path: String, debug_write := false) -> Script:
+	if not GdUnit4CSharpApiLoader.is_api_loaded():
+		return null
+	var script :Script = ClassDB.instantiate("CSharpScript")
+	script.source_code = GdUnitFileAccess.resource_as_string(resource_path)
+	var script_resource_path := resource_path.replace(resource_path.get_extension(), "cs")
+	if debug_write:
+		script_resource_path = GdUnitFileAccess.create_temp_dir("test") + "/%s" % script_resource_path.get_file()
+		print_debug("save resource:", script_resource_path)
+		DirAccess.remove_absolute(script_resource_path)
+		var err := ResourceSaver.save(script, script_resource_path)
+		if err != OK:
+			print_debug("Can't save debug resource",script_resource_path, "Error:", error_string(err))
+		script.take_over_path(script_resource_path)
+	else:
+		script.take_over_path(resource_path)
+	script.reload()
+	return script
+
+
+static func load_gd_script(resource_path: String, debug_write := false) -> GDScript:
+		# grap current level
+	var unsafe_method_access: Variant = ProjectSettings.get_setting("debug/gdscript/warnings/unsafe_method_access")
+	# disable and load the script
+	ProjectSettings.set_setting("debug/gdscript/warnings/unsafe_method_access", 0)
+
+	var script := GDScript.new()
+	script.source_code = GdUnitFileAccess.resource_as_string(resource_path)
+	var script_resource_path := resource_path.replace(resource_path.get_extension(), "gd")
+	if debug_write:
+		script_resource_path = script_resource_path.replace("res://", GdUnitFileAccess.temp_dir() + "/")
+		#print_debug("save resource: ", script_resource_path)
+		DirAccess.remove_absolute(script_resource_path)
+		DirAccess.make_dir_recursive_absolute(script_resource_path.get_base_dir())
+		var err := ResourceSaver.save(script, script_resource_path, ResourceSaver.FLAG_REPLACE_SUBRESOURCE_PATHS)
+		if err != OK:
+			print_debug("Can't save debug resource", script_resource_path, "Error:", error_string(err))
+		script.take_over_path(script_resource_path)
+	else:
+		script.take_over_path(resource_path)
+	var error := script.reload()
+	if error != OK:
+		push_error("Errors on loading script %s. Error: %s" % [resource_path, error_string(error)])
+	ProjectSettings.set_setting("debug/gdscript/warnings/unsafe_method_access", unsafe_method_access)
+	return script
+	#@warning_ignore("unsafe_cast")