Add test for num instances in machine manager

tests/TestMachineManager.py

@@ -7,20 +7,29 @@ from cura.Settings.ExtruderManager import ExtruderManager
 from cura.Settings.MachineManager import MachineManager
 
 
+@pytest.fixture()
+def global_stack():
+    return MagicMock(name="Global Stack")
+
 @pytest.fixture()
 def container_registry() -> ContainerRegistry:
-    return MagicMock()
+    return MagicMock(name = "ContainerRegistry")
 
 @pytest.fixture()
 def extruder_manager(application, container_registry) -> ExtruderManager:
+    if ExtruderManager.getInstance() is not None:
+        # Reset the data
+        ExtruderManager._ExtruderManager__instance = None
+
     with patch("cura.CuraApplication.CuraApplication.getInstance", MagicMock(return_value=application)):
         with patch("UM.Settings.ContainerRegistry.ContainerRegistry.getInstance", MagicMock(return_value=container_registry)):
-                manager = ExtruderManager()
+            manager = ExtruderManager()
     return manager
 
 @pytest.fixture()
-def machine_manager(application, extruder_manager, container_registry) -> MachineManager:
+def machine_manager(application, extruder_manager, container_registry, global_stack) -> MachineManager:
     application.getExtruderManager = MagicMock(return_value = extruder_manager)
+    application.getGlobalContainerStack = MagicMock(return_value = global_stack)
     with patch("cura.Settings.CuraContainerRegistry.CuraContainerRegistry.getInstance", MagicMock(return_value=container_registry)):
         manager = MachineManager(application)
 
@@ -41,3 +50,13 @@ def test_setActiveMachine(machine_manager):
             # Although we mocked the application away, we still want to know if it was notified about the attempted change.
             machine_manager._application.setGlobalContainerStack.assert_called_with(mocked_global_stack)
 
+
+def test_hasUserSettings(machine_manager, application):
+    mocked_stack = application.getGlobalContainerStack()
+
+    mocked_instance_container = MagicMock(name="UserSettingContainer")
+    mocked_instance_container.getNumInstances = MagicMock(return_value = 12)
+    mocked_stack.getTop = MagicMock(return_value = mocked_instance_container)
+
+    assert machine_manager.numUserSettings == 12
+    assert machine_manager.hasUserSettings