Test non-rooted classifications in IDS

src/ifctester/test/test_facet.py

@@ -697,6 +697,10 @@ class TestClassification:
             classification=system_a,
             is_lightweight=False,
         )
+        material = ifc.createIfcMaterial(Name="Material")
+        ifcopenshell.api.run(
+            "classification.add_reference", ifc, product=material, reference=ref1, classification=system_a
+        )
 
         facet = Classification()
         run(
@@ -728,6 +732,14 @@ class TestClassification:
             expected=True,
         )
 
+        facet = Classification(value="1")
+        run(
+            "Non-rooted resources that have external classification references should also pass",
+            facet=facet,
+            inst=material,
+            expected=True,
+        )
+
         facet = Classification(system="Foobar")
         run("Systems should match exactly 1/5", facet=facet, inst=project, expected=True)
         run("Systems should match exactly 2/5", facet=facet, inst=element0, expected=False)