Refs #26709 -- Added IndexOperation to avoid code duplication.

django/db/migrations/operations/models.py

@@ -744,7 +744,15 @@ class AlterModelManagers(ModelOptionOperation):
         return "Change managers on %s" % (self.name, )
 
 
-class AddIndex(Operation):
+class IndexOperation(Operation):
+    option_name = 'indexes'
+
+    @cached_property
+    def model_name_lower(self):
+        return self.model_name.lower()
+
+
+class AddIndex(IndexOperation):
     """
     Add an index on a model.
     """
@@ -759,9 +767,9 @@ class AddIndex(Operation):
         self.index = index
 
     def state_forwards(self, app_label, state):
-        model_state = state.models[app_label, self.model_name.lower()]
+        model_state = state.models[app_label, self.model_name_lower]
         self.index.model = state.apps.get_model(app_label, self.model_name)
-        model_state.options['indexes'].append(self.index)
+        model_state.options[self.option_name].append(self.index)
 
     def database_forwards(self, app_label, schema_editor, from_state, to_state):
         schema_editor.add_index(self.index)
@@ -787,7 +795,7 @@ class AddIndex(Operation):
         )
 
 
-class RemoveIndex(Operation):
+class RemoveIndex(IndexOperation):
     """
     Remove an index from a model.
     """
@@ -797,17 +805,17 @@ class RemoveIndex(Operation):
         self.name = name
 
     def state_forwards(self, app_label, state):
-        model_state = state.models[app_label, self.model_name.lower()]
-        indexes = model_state.options['indexes']
-        model_state.options['indexes'] = [idx for idx in indexes if idx.name != self.name]
+        model_state = state.models[app_label, self.model_name_lower]
+        indexes = model_state.options[self.option_name]
+        model_state.options[self.option_name] = [idx for idx in indexes if idx.name != self.name]
 
     def database_forwards(self, app_label, schema_editor, from_state, to_state):
-        from_model_state = from_state.models[app_label, self.model_name.lower()]
+        from_model_state = from_state.models[app_label, self.model_name_lower]
         index = from_model_state.get_index_by_name(self.name)
         schema_editor.remove_index(index)
 
     def database_backwards(self, app_label, schema_editor, from_state, to_state):
-        to_model_state = to_state.models[app_label, self.model_name.lower()]
+        to_model_state = to_state.models[app_label, self.model_name_lower]
         index = to_model_state.get_index_by_name(self.name)
         schema_editor.add_index(index)