Add initial tests for variantNode

CURA-6600

tests/Machines/TestVariantNode.py

@@ -0,0 +1,54 @@
+from unittest.mock import patch, MagicMock
+import pytest
+
+from cura.Machines.VariantNode import VariantNode
+
+
+metadata_dict = {"fdmprinter": {"no_variant": [{"base_file": "material_1", "id": "material_1"}, {"base_file": "material_2", "id": "material_2"}]},
+                 "machine_1": {"no_variant": [{"base_file": "material_1", "id": "material_1"}, {"base_file": "material_2", "id": "material_2"}],
+                               "Variant One": [{"base_file": "material_1", "id": "material_1"}, {"base_file": "material_2", "id": "material_2"}]}}
+
+
+def getMetadataEntrySideEffect(*args, **kwargs):
+    variant = kwargs.get("variant")
+    definition = kwargs.get("definition")
+
+    if variant is not None:
+        return metadata_dict.get(definition).get(variant)
+    return metadata_dict.get(definition).get("no_variant")
+
+
+@pytest.fixture
+def machine_node():
+    mocked_machine_node = MagicMock()
+    mocked_machine_node.container_id = "machine_1"
+    return mocked_machine_node
+
+
+@pytest.fixture
+def container_registry():
+    result = MagicMock()
+    result.findInstanceContainersMetadata = MagicMock(side_effect = getMetadataEntrySideEffect)
+    result.findContainersMetadata = MagicMock(return_value = [{"name": "Variant One"}])
+    return result
+
+
+def test_variantNodeInit(container_registry, machine_node):
+    with patch("cura.Machines.VariantNode.MaterialNode"):  # We're not testing the material node here, so patch it out.
+        with patch("UM.Settings.ContainerRegistry.ContainerRegistry.getInstance", MagicMock(return_value=container_registry)):
+            node = VariantNode("variant_1", machine_node)
+
+    assert "material_1" in node.materials
+    assert "material_2" in node.materials
+    assert len(node.materials) == 2
+
+
+def test_variantNodeInit_excludedMaterial(container_registry, machine_node):
+    machine_node.exclude_materials = ["material_1"]
+    with patch("cura.Machines.VariantNode.MaterialNode"):  # We're not testing the material node here, so patch it out.
+        with patch("UM.Settings.ContainerRegistry.ContainerRegistry.getInstance", MagicMock(return_value=container_registry)):
+            node = VariantNode("variant_1", machine_node)
+
+    assert "material_1" not in node.materials
+    assert "material_2" in node.materials
+    assert len(node.materials) == 1