assigning material styles to reuse existing styled item + tests

src/ifcopenshell-python/test/api/style/test_unassign_material_style.py

@@ -0,0 +1,47 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2022 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import pytest
+import test.bootstrap
+import ifcopenshell
+import ifcopenshell.api
+
+
+class TestAssignMaterialStyle(test.bootstrap.IFC4):
+    def test_run(self):
+        material = ifcopenshell.api.run("material.add_material", self.file)
+        context = self.file.createIfcGeometricRepresentationContext()
+        style = self.file.createIfcSurfaceStyle()
+        ifcopenshell.api.run("style.assign_material_style", self.file, material=material, style=style, context=context)
+
+        # unassign 1 style
+        style2 = self.file.createIfcSurfaceStyle()
+        item = self.file.by_type("IfcStyledItem")[0]
+        item.Styles = item.Styles + (style2,)
+        ifcopenshell.api.run(
+            "style.unassign_material_style", self.file, material=material, style=style2, context=context
+        )
+        assert item.Styles == (style,)
+
+        # unassign last style
+        ifcopenshell.api.run(
+            "style.unassign_material_style", self.file, material=material, style=style, context=context
+        )
+        assert len(self.file.by_type("IfcMaterialDefinitionRepresentation")) == 0
+        assert len(self.file.by_type("IfcStyledRepresentation")) == 0
+        assert len(self.file.by_type("IfcStyledItem")) == 0