Added simple test for BuildVolume

tests/TestBuildVolume.py

@@ -0,0 +1,27 @@
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from cura.BuildVolume import BuildVolume
+
+@pytest.fixture
+def build_volume():
+    mocked_application = MagicMock()
+    mocked_platform = MagicMock(name="platform")
+    with patch("cura.BuildVolume.Platform", mocked_platform):
+        return BuildVolume(mocked_application)
+
+
+def test_buildVolumeSetSizes(build_volume):
+    build_volume.setWidth(10)
+    assert build_volume.getDiagonalSize() == 10
+
+    build_volume.setWidth(0)
+    build_volume.setHeight(100)
+    assert build_volume.getDiagonalSize() == 100
+
+    build_volume.setHeight(0)
+    build_volume.setDepth(200)
+    assert build_volume.getDiagonalSize() == 200
+
+