Fix and test importing style attributes twice (#1784)

* Test importing surface attributes twice

* Fix style attributes not cleared when re-importing

src/blenderbim/blenderbim/tool/style.py

@@ -103,6 +103,7 @@ class Style(blenderbim.core.tool.Style):
 
     @classmethod
     def import_surface_attributes(cls, style, obj):
+        obj.BIMStyleProperties.attributes.clear()
         blenderbim.bim.helper.import_attributes2(style, obj.BIMStyleProperties.attributes)
 
     @classmethod

src/blenderbim/test/tool/test_style.py

@@ -163,6 +163,19 @@ class TestImportSurfaceAttributes(NewFile):
         assert obj.BIMStyleProperties.attributes.get("Name").string_value == "Name"
         assert obj.BIMStyleProperties.attributes.get("Side").enum_value == "BOTH"
 
+    def test_importing_surface_attributes_twice(self):
+        ifc = ifcopenshell.file()
+        style = ifc.createIfcSurfaceStyle("Name", "BOTH")
+        obj = bpy.data.materials.new("Material")
+        subject.import_surface_attributes(style, obj)
+        assert len(obj.BIMStyleProperties.attributes) == 2
+        assert obj.BIMStyleProperties.attributes.get("Name").string_value == "Name"
+        assert obj.BIMStyleProperties.attributes.get("Side").enum_value == "BOTH"
+        subject.import_surface_attributes(style, obj)
+        assert len(obj.BIMStyleProperties.attributes) == 2
+        assert obj.BIMStyleProperties.attributes.get("Name").string_value == "Name"
+        assert obj.BIMStyleProperties.attributes.get("Side").enum_value == "BOTH"
+
 
 class TestLink(NewFile):
     def test_run(self):