Add a test that exposes the association copy/paste issue

tests/test_multiple_associations.py

@@ -0,0 +1,115 @@
+"""
+Test issues where associations are copied and pasted, deleted, etc.
+
+Scenario's:
+* Class and association are pasted in a new diagramg
+* Class and association are pasted in a new diagram and original association is deleted
+* Class and association are pasted in a new diagram and new association is deleted
+* Association is pasted in a new diagram and reconnected to the class (same subject as original)
+* Association is pasted and directly deleted
+* Class and association are pasted in a new diagram and one end is connected to a different class
+
+"""
+
+import pytest
+
+from gaphor import UML
+from gaphor.application import Session
+from gaphor.diagram.tests.fixtures import connect
+from gaphor.UML import diagramitems
+from gaphor.UML.modelfactory import set_navigability
+
+
+@pytest.fixture
+def session():
+    session = Session()
+    yield session
+    session.shutdown()
+
+
+@pytest.fixture
+def element_factory(session):
+    return session.get_service("element_factory")
+
+
+@pytest.fixture
+def copy(session):
+    return session.get_service("copy")
+
+
+@pytest.fixture
+def diagram(element_factory):
+    return element_factory.create(UML.Diagram)
+
+
+@pytest.fixture
+def class_and_association_with_copy(diagram, element_factory, copy):
+    c = diagram.create(
+        diagramitems.ClassItem, subject=element_factory.create(UML.Class)
+    )
+
+    a = diagram.create(diagramitems.AssociationItem)
+    connect(a, a.handles()[0], c)
+    connect(a, a.handles()[1], c)
+
+    set_navigability(a.subject, a.subject.memberEnd[0], True)
+
+    copy.copy({a, c})
+    new_diagram = element_factory.create(UML.Diagram)
+    pasted_items = copy.paste(new_diagram)
+
+    aa = pasted_items.pop()
+    if not isinstance(aa, diagramitems.AssociationItem):
+        aa = pasted_items.pop()
+
+    return c, a, aa
+
+
+def test_delete_copied_associations(class_and_association_with_copy):
+
+    c, a, aa = class_and_association_with_copy
+
+    assert a.subject.memberEnd[0].type
+    assert a.subject.memberEnd[1].type
+    assert a.subject.memberEnd[0].type is c.subject
+    assert a.subject.memberEnd[1].type is c.subject
+    assert a.subject.memberEnd[0] is a.head_end.subject
+    assert a.subject.memberEnd[1] is a.tail_end.subject
+    assert a.subject.memberEnd[0] in a.subject.memberEnd[1].type.ownedAttribute
+
+    # Delete the copy and all is fine
+
+    aa.unlink()
+
+    assert a.subject.memberEnd[0].type
+    assert a.subject.memberEnd[1].type
+    assert a.subject.memberEnd[0].type is c.subject
+    assert a.subject.memberEnd[1].type is c.subject
+    assert a.subject.memberEnd[0] is a.head_end.subject
+    assert a.subject.memberEnd[1] is a.tail_end.subject
+    assert a.subject.memberEnd[0] in a.subject.memberEnd[1].type.ownedAttribute
+
+
+def test_delete_original_association(class_and_association_with_copy):
+
+    c, a, aa = class_and_association_with_copy
+
+    assert aa.subject.memberEnd[0].type
+    assert aa.subject.memberEnd[1].type
+    assert aa.subject.memberEnd[0].type is c.subject
+    assert aa.subject.memberEnd[1].type is c.subject
+    assert aa.subject.memberEnd[0] is aa.head_end.subject
+    assert aa.subject.memberEnd[1] is aa.tail_end.subject
+    assert aa.subject.memberEnd[0] in aa.subject.memberEnd[1].type.ownedAttribute
+
+    # Now, when the original is deleted, the model is changed and made invalid
+
+    a.unlink()
+
+    assert aa.subject.memberEnd[0].type
+    assert aa.subject.memberEnd[1].type
+    assert aa.subject.memberEnd[0].type is c.subject
+    assert aa.subject.memberEnd[1].type is c.subject
+    assert aa.subject.memberEnd[0] is aa.head_end.subject
+    assert aa.subject.memberEnd[1] is aa.tail_end.subject
+    assert aa.subject.memberEnd[0] in aa.subject.memberEnd[1].type.ownedAttribute