Add tests for ExtruderManager

tests/conftest.py

@@ -11,9 +11,12 @@ import Savitar  # Dont remove this line
 import Arcus  # No really. Don't. It needs to be there!
 from UM.Qt.QtApplication import QtApplication  # QtApplication import is required, even though it isn't used.
 # Even though your IDE says these files are not used, don't believe it. It's lying. They need to be there.
+from UM.Settings.ContainerRegistry import ContainerRegistry
 
 from cura.CuraApplication import CuraApplication
+from cura.Settings.ExtruderManager import ExtruderManager
 from cura.UI.MachineActionManager import MachineActionManager
+from unittest.mock import MagicMock, patch
 
 # Create a CuraApplication object that will be shared among all tests. It needs to be initialized.
 # Since we need to use it more that once, we create the application the first time and use its instance afterwards.
@@ -22,7 +25,24 @@ def application() -> CuraApplication:
     app = unittest.mock.MagicMock()
     return app
 
+
+@pytest.fixture()
+def container_registry() -> ContainerRegistry:
+    return MagicMock(name = "ContainerRegistry")
+
+
 # Returns a MachineActionManager instance.
 @pytest.fixture()
 def machine_action_manager(application) -> MachineActionManager:
     return MachineActionManager(application)
+
+@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()
+    return manager