Tests and a fix for BaseStore.parent

- add unit tests for BaseStore.parent
- ensure that the store is unchanged when called with invalid IDs
- add helpful error messages to the exceptions

GTG/core/base_store.py

@@ -179,19 +179,17 @@ def batch_remove(self,item_ids: list[UUID]) -> None:
     def parent(self, item_id: UUID, parent_id: UUID) -> None:
         """Add a child to an item."""
 
-        try:
-            item = self.lookup[item_id]
-        except KeyError:
-            raise
+        if item_id not in self.lookup:
+            raise KeyError("item_id is not in store: "+str(item_id))
+        if parent_id not in self.lookup:
+            raise KeyError("parent_id is not in store: "+str(parent_id))
 
-        try:
-            self.data.remove(item)
-            self.lookup[parent_id].children.append(item)
-            item.parent = self.lookup[parent_id]
+        item = self.lookup[item_id]
+        item.parent = self.lookup[parent_id]
 
-            self.emit('parent-change', item, self.lookup[parent_id])
-        except KeyError:
-            raise
+        self.data.remove(item)
+        self.lookup[parent_id].children.append(item)
+        self.emit('parent-change', item, self.lookup[parent_id])
 
 
     def unparent(self, item_id: UUID, parent_id: UUID) -> None:

tests/core/test_base_store.py

@@ -67,3 +67,69 @@ def on_remove(obj,s):
         self.store.connect('removed',on_remove)
         self.store.remove(self.tree_items[0].id)
         self.assertEqual(removed,{ str(item.id) for item in self.tree_items })
+
+
+
+class BaseStoreParent(TestCase):
+
+
+    def setUp(self):
+        self.store = BaseStore()
+
+        self.root1 = StoreItem(uuid4())
+        self.root2 = StoreItem(uuid4())
+        self.child = StoreItem(uuid4())
+        self.invalid_id = uuid4()
+
+        self.store.add(self.root1)
+        self.store.add(self.root2)
+        self.store.add(self.child,parent_id=self.root1.id)
+
+
+    def test_parent_is_set(self):
+        self.store.parent(self.root2.id,self.root1.id)
+        self.assertEqual(self.root2.parent,self.root1)
+
+
+    def test_children_list_is_updated(self):
+        self.store.parent(self.root2.id,self.root1.id)
+        self.assertTrue(self.root2 in self.root1.children)
+
+
+    def test_root_elements_are_updated(self):
+        self.store.parent(self.root2.id,self.root1.id)
+        self.assertEqual(self.store.count(root_only=True),1)
+
+
+    def test_invalid_item_id_raises_exception(self):
+        with self.assertRaises(KeyError):
+            self.store.parent(self.invalid_id,self.root1.id)
+
+
+    def test_invalid_item_id_does_not_update_children(self):
+        try:
+            self.store.parent(self.invalid_id,self.root1.id)
+        except KeyError:
+            pass
+        self.assertTrue(self.invalid_id not in self.root1.children)
+
+
+    def test_invalid_parent_id_raises_exception(self):
+        with self.assertRaises(KeyError):
+            self.store.parent(self.root1.id,self.invalid_id)
+
+
+    def test_invalid_parent_id_does_not_update_parent(self):
+        try:
+            self.store.parent(self.root1.id,self.invalid_id)
+        except KeyError:
+            pass
+        self.assertEqual(self.root1.parent,None)
+
+
+    def test_invalid_parent_id_does_not_update_root_elements(self):
+        try:
+            self.store.parent(self.root1.id,self.invalid_id)
+        except KeyError:
+            pass
+        self.assertEqual(self.store.count(root_only=True),2)