Make entity items correctly advertise if they have children

This fixes a bug in DB Editor's Entity tree where the ND entities at deeper
levels of the tree did not show up as expandable even though they had
children.

Re #3242

Author: soininen

spinetoolbox/spine_db_editor/mvcmodels/entity_tree_item.py

@@ -345,6 +345,17 @@ def _handle_entity_group_items_removed(self, db_map_data):
             self._is_group = False
             self.parent_item.reposition_child(self.child_number())
 
+    def _polish_children(self, children):
+        """See base class."""
+        db_map_entity_element_ids = {
+            db_map: {el_id for ent in self.db_mngr.get_items(db_map, "entity") for el_id in ent["element_id_list"]}
+            for db_map in self.db_maps
+        }
+        for child in children:
+            child.set_has_children_initially(
+                any(child.db_map_id(db_map) in db_map_entity_element_ids.get(db_map, ()) for db_map in child.db_maps)
+            )
+
     def tear_down(self):
         super().tear_down()
         self._entity_group_fetch_parent.set_obsolete(True)

tests/spine_db_editor/mvcmodels/test_entity_tree_models.py

@@ -25,3 +25,39 @@ def test_superclass_name_displayed_after_subclass_name(self, db_editor, db_mngr,
         while len(model.root_item.children) != 2:
             QApplication.processEvents()
         assert [child.display_data for child in model.root_item.children] == ["Any", "Object (Any)"]
+
+    def test_entity_items_advertise_they_have_children(self, db_editor, db_mngr, db_map):
+        with db_map:
+            db_map.add_entity_class(name="A")
+            db_map.add_entity(entity_class_name="A", name="a")
+            db_map.add_entity_class(name="B")
+            db_map.add_entity(entity_class_name="B", name="b")
+            db_map.add_entity_class(dimension_name_list=["A", "B"])
+            db_map.add_entity(entity_class_name="A__B", entity_byname=["a", "b"])
+            db_map.add_entity_class(dimension_name_list=["A__B", "A__B"])
+            db_map.add_entity(entity_class_name="A__B__A__B", entity_byname=["a", "b", "a", "b"])
+        model = EntityTreeModel(db_editor, db_mngr, db_map)
+        model.build_tree()
+        model.root_item.fetch_more()
+        while len(model.root_item.children) != 4:
+            QApplication.processEvents()
+        assert [child.display_data for child in model.root_item.children] == ["A", "B", "A__B", "A__B__A__B"]
+        assert all(child.has_children() for child in model.root_item.children)
+        class_a = model.root_item.children[0]
+        class_a.fetch_more()
+        while len(class_a.children) != 1:
+            QApplication.processEvents()
+        assert [entity_item.display_data for entity_item in class_a.children] == ["a"]
+        assert all(entity_item.has_children() for entity_item in class_a.children)
+        entity_a = class_a.children[0]
+        entity_a.fetch_more()
+        while len(entity_a.children) != 1:
+            QApplication.processEvents()
+        assert [entity_item.display_data for entity_item in entity_a.children] == ["٭ ǀ b"]
+        assert all(entity_item.has_children() for entity_item in entity_a.children)
+        relationship_a_b = entity_a.children[0]
+        relationship_a_b.fetch_more()
+        while len(relationship_a_b.children) != 1:
+            QApplication.processEvents()
+        assert [relationship.display_data for relationship in relationship_a_b.children] == ["٭ ǀ ٭ ǀ ٭ ǀ ٭"]
+        assert all(not relationship.has_children() for relationship in relationship_a_b.children)