#2094. Deleting materials now also deletes Blender material if not used for a style

src/blenderbim/test/bim/feature/material.feature

@@ -46,8 +46,18 @@ Scenario: Remove material
     And the object "Cube" is selected
     And I add a material
     And I press "bim.add_material(obj='Material')"
-    When I press "bim.remove_material"
-    Then the material "Material" is not an IFC material
+    And the variable "material" is "{ifc}.by_type('IfcMaterial')[0].id()"
+    When I press "bim.remove_material(material={material})"
+    Then the material "Material" does not exist
+
+Scenario: Remove material set
+    Given an empty IFC project
+    And I set "scene.BIMMaterialProperties.material_type" to "IfcMaterialLayerSet"
+    And I press "bim.load_materials"
+    And I press "bim.add_material_set(set_type='IfcMaterialLayerSet')"
+    And the variable "material" is "{ifc}.by_type('IfcMaterialLayerSet')[0].id()"
+    When I press "bim.remove_material_set(material={material})"
+    Then nothing happens
 
 Scenario: Unlink material
     Given an empty IFC project

src/blenderbim/test/bim/test_feature.py

@@ -297,6 +297,11 @@ def the_material_name_exists(name) -> bpy.types.Material:
     return obj
 
 
+@then(parsers.parse('the material "{name}" does not exist'))
+def the_material_name_does_not_exist(name):
+    assert bpy.data.materials.get(name) is None, "Material exists"
+
+
 @then("an IFC file does not exist")
 def an_ifc_file_does_not_exist():
     ifc = IfcStore.get_file()

src/blenderbim/test/core/test_material.py

@@ -92,6 +92,50 @@ class TestAddMaterialSet:
         assert subject.add_material_set(ifc, material, set_type="set_type") == "material"
 
 
+class TestRemoveMaterial:
+    def test_removing_a_material(self, ifc, material, style):
+        ifc.get_object("material").should_be_called().will_return(None)
+        ifc.unlink(element="material").should_be_called()
+        ifc.run("material.remove_material", material="material").should_be_called()
+        material.is_editing_materials().should_be_called().will_return(False)
+        subject.remove_material(ifc, material, style, material="material")
+
+    def test_removing_a_material_and_reloading_imported_materials(self, ifc, material, style):
+        ifc.get_object("material").should_be_called().will_return(None)
+        ifc.unlink(element="material").should_be_called()
+        ifc.run("material.remove_material", material="material").should_be_called()
+        material.is_editing_materials().should_be_called().will_return(True)
+        material.get_active_material_type().should_be_called().will_return("material_type")
+        material.import_material_definitions("material_type").should_be_called()
+        subject.remove_material(ifc, material, style, material="material")
+
+    def test_removing_a_material_object_if_it_has_no_style(self, ifc, material, style):
+        ifc.get_object("material").should_be_called().will_return("obj")
+        ifc.unlink(element="material").should_be_called()
+        ifc.run("material.remove_material", material="material").should_be_called()
+        style.get_style("obj").should_be_called().will_return(None)
+        material.delete_object("obj").should_be_called()
+        material.is_editing_materials().should_be_called().will_return(False)
+        subject.remove_material(ifc, material, style, material="material")
+
+    def test_preserving_a_material_object_if_it_is_still_used_as_a_style(self, ifc, material, style):
+        ifc.get_object("material").should_be_called().will_return("obj")
+        ifc.unlink(element="material").should_be_called()
+        ifc.run("material.remove_material", material="material").should_be_called()
+        style.get_style("obj").should_be_called().will_return("style")
+        material.is_editing_materials().should_be_called().will_return(False)
+        subject.remove_material(ifc, material, style, material="material")
+
+
+class TestRemoveMaterialSet:
+    def test_run(self, ifc, material):
+        ifc.run("material.remove_material_set", material="material").should_be_called()
+        material.is_editing_materials().should_be_called().will_return(True)
+        material.get_active_material_type().should_be_called().will_return("material_type")
+        material.import_material_definitions("material_type").should_be_called()
+        subject.remove_material_set(ifc, material, material="material")
+
+
 class TestLoadMaterials:
     def test_run(self, material):
         material.import_material_definitions("material_type").should_be_called()

src/blenderbim/test/tool/test_material.py

@@ -36,6 +36,14 @@ class TestAddDefaultMaterialObject(NewFile):
         assert material.name == "Default"
 
 
+class TestDeleteObject(NewFile):
+    def test_run(self):
+        material = subject.add_default_material_object()
+        assert bpy.data.materials.get("Default")
+        subject.delete_object(material)
+        assert not bpy.data.materials.get("Default")
+
+
 class TestDisableEditingMaterials(NewFile):
     def test_run(self):
         bpy.context.scene.BIMMaterialProperties.is_editing = True