Naive implementation of a backwards-compatible function_name decorator

azure/functions/decorators/function_app.py

@@ -288,6 +288,30 @@ def app_script_file(self) -> str:
         """
         return self._app_script_file
 
+    def _function_name(self, name: str,
+                       setting_extra_fields: Dict[str, Any] = {},
+                       ) -> Callable[..., Any]:
+        """Optional: Sets name of the :class:`Function` object. If not set,
+        it will default to the name of the method name.
+
+        :param name: Name of the function.
+        :param setting_extra_fields: Keyword arguments for specifying
+        additional setting fields
+        :return: Decorator function.
+        """
+
+        @self._configure_function_builder
+        def wrap(fb):
+            def decorator():
+                fb.add_setting(setting=FunctionName(
+                    function_name=name,
+                    **setting_extra_fields))
+                return fb
+
+            return decorator()
+
+        return wrap
+
     def _validate_type(self,
                        func: Union[Callable[..., Any], FunctionBuilder]) \
             -> FunctionBuilder:
@@ -419,6 +443,20 @@ def decorator():
 
         return wrap
 
+    def function_name(self, name: str,
+                      setting_extra_fields: Dict[str, Any] = {},
+                      ) -> Callable[..., Any]:
+        """Optional: Sets name of the :class:`Function` object. If not set,
+        it will default to the name of the method name.
+
+        :param name: Name of the function.
+        :param setting_extra_fields: Keyword arguments for specifying
+        additional setting fields
+        :return: Decorator function.
+        """
+
+        return self._function_name(name, setting_extra_fields)
+
     def timer_trigger(self,
                       arg_name: str,
                       schedule: str,
@@ -2613,17 +2651,7 @@ def function_name(self, name: str,
         :return: Decorator function.
         """
 
-        @self._configure_function_builder
-        def wrap(fb):
-            def decorator():
-                fb.add_setting(setting=FunctionName(
-                    function_name=name,
-                    **setting_extra_fields))
-                return fb
-
-            return decorator()
-
-        return wrap
+        return self._function_name(name, setting_extra_fields)
 
     def retry(self,
               strategy: str,

tests/decorators/test_function_app.py

@@ -11,10 +11,10 @@
     TIMER_TRIGGER
 from azure.functions.decorators.core import DataType, AuthLevel, \
     BindingDirection, SCRIPT_FILE_NAME
-from azure.functions.decorators.function_app import FunctionBuilder, \
-    FunctionApp, Function, Blueprint, DecoratorApi, AsgiFunctionApp, \
-    WsgiFunctionApp, HttpFunctionsAuthLevelMixin, FunctionRegister, \
-    TriggerApi, ExternalHttpFunctionApp
+from azure.functions.decorators.function_app import BindingApi, \
+    FunctionBuilder, FunctionApp, Function, Blueprint, DecoratorApi, \
+    AsgiFunctionApp, WsgiFunctionApp, HttpFunctionsAuthLevelMixin, \
+    FunctionRegister, TriggerApi, ExternalHttpFunctionApp
 from azure.functions.decorators.http import HttpTrigger, HttpOutput, \
     HttpMethod
 from azure.functions.decorators.retry_policy import RetryPolicy
@@ -489,6 +489,31 @@ def hello(name: str):
         self.assertEqual(setting.get_settings_value("function_name"),
                          "timer_function")
 
+    def test_legacy_blueprints_with_function_name(self):
+        class LegacyBluePrint(TriggerApi, BindingApi):
+            pass
+
+        class DummyFunctionApp(FunctionRegister, TriggerApi):
+            pass
+
+        app = DummyFunctionApp(auth_level=AuthLevel.ANONYMOUS)
+        blueprint = LegacyBluePrint()
+
+        @blueprint.function_name("timer_function")
+        @blueprint.schedule(arg_name="name", schedule="10****")
+        def hello(name: str):
+            return name
+
+        app.register_blueprint(blueprint)
+
+        functions = app.get_functions()
+        self.assertEqual(len(functions), 1)
+
+        setting = functions[0].get_setting("function_name")
+
+        self.assertEqual(setting.get_settings_value("function_name"),
+                         "timer_function")
+
     def test_function_register_register_function_register_error(self):
         class DummyFunctionApp(FunctionRegister):
             pass