Enabled implicit output for generic bindings

azure_functions_worker/bindings/generic.py

@@ -51,5 +51,7 @@ def decode(cls, data: datumdef.Datum, *, trigger_metadata) -> typing.Any:
         return result
 
     @classmethod
-    def has_implicit_output(cls) -> bool:
-        return False
+    def has_implicit_output(cls, bind_name: Optional[str]) -> bool:
+        if bind_name == 'durableClient':
+            return False
+        return True

azure_functions_worker/bindings/meta.py

@@ -55,9 +55,15 @@ def check_output_type_annotation(bind_name: str, pytype: type) -> bool:
 def has_implicit_output(bind_name: str) -> bool:
     binding = get_binding(bind_name)
 
-    # If the binding does not have metaclass of meta.InConverter
-    # The implicit_output does not exist
-    return getattr(binding, 'has_implicit_output', lambda: False)()
+    # Need to pass in bind_name to exempt Durable Functions
+    if binding is generic.GenericBinding:
+        return (getattr(binding, 'has_implicit_output', lambda: False)
+                (bind_name))
+
+    else:
+        # If the binding does not have metaclass of meta.InConverter
+        # The implicit_output does not exist
+        return getattr(binding, 'has_implicit_output', lambda: False)()
 
 
 def from_incoming_proto(

azure_functions_worker/functions.py

@@ -71,14 +71,20 @@ def get_explicit_and_implicit_return(binding_name: str,
     @staticmethod
     def get_return_binding(binding_name: str,
                            binding_type: str,
-                           return_binding_name: str) -> str:
+                           return_binding_name: str,
+                           explicit_return_val_set: bool) \
+            -> typing.Tuple[str, bool]:
+        # prioritize explicit return value
+        if explicit_return_val_set:
+            return return_binding_name, explicit_return_val_set
         if binding_name == "$return":
             return_binding_name = binding_type
             assert return_binding_name is not None
+            explicit_return_val_set = True
         elif bindings_utils.has_implicit_output(binding_type):
             return_binding_name = binding_type
 
-        return return_binding_name
+        return return_binding_name, explicit_return_val_set
 
     @staticmethod
     def validate_binding_direction(binding_name: str,
@@ -314,6 +320,7 @@ def add_function(self, function_id: str,
         params = dict(sig.parameters)
         annotations = typing.get_type_hints(func)
         return_binding_name: typing.Optional[str] = None
+        explicit_return_val_set = False
         has_explicit_return = False
         has_implicit_return = False
 
@@ -327,9 +334,11 @@ def add_function(self, function_id: str,
                     binding_name, binding_info, has_explicit_return,
                     has_implicit_return, bound_params)
 
-            return_binding_name = self.get_return_binding(binding_name,
-                                                          binding_info.type,
-                                                          return_binding_name)
+            return_binding_name, explicit_return_val_set = \
+                self.get_return_binding(binding_name,
+                                        binding_info.type,
+                                        return_binding_name,
+                                        explicit_return_val_set)
 
         requires_context = self.is_context_required(params, bound_params,
                                                     annotations,
@@ -362,6 +371,7 @@ def add_indexed_function(self, function):
         function_id = str(uuid.uuid5(namespace=uuid.NAMESPACE_OID,
                                      name=func_name))
         return_binding_name: typing.Optional[str] = None
+        explicit_return_val_set = False
         has_explicit_return = False
         has_implicit_return = False
 
@@ -381,9 +391,11 @@ def add_indexed_function(self, function):
                     binding.name, binding, has_explicit_return,
                     has_implicit_return, bound_params)
 
-            return_binding_name = self.get_return_binding(binding.name,
-                                                          binding.type,
-                                                          return_binding_name)
+            return_binding_name, explicit_return_val_set = \
+                self.get_return_binding(binding.name,
+                                        binding.type,
+                                        return_binding_name,
+                                        explicit_return_val_set)
 
         requires_context = self.is_context_required(params, bound_params,
                                                     annotations,

tests/endtoend/generic_functions/generic_functions_stein/function_app.py

@@ -0,0 +1,31 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+import azure.functions as func
+
+app = func.FunctionApp(http_auth_level=func.AuthLevel.ANONYMOUS)
+
+
+@app.function_name(name="return_processed_last")
+@app.generic_trigger(arg_name="req", type="httpTrigger",
+                     route="return_processed_last")
+@app.generic_output_binding(arg_name="$return", type="http")
+@app.generic_input_binding(
+    arg_name="testEntity",
+    type="table",
+    connection="AzureWebJobsStorage",
+    table_name="EventHubBatchTest")
+def return_processed_last(req: func.HttpRequest, testEntity):
+    return func.HttpResponse(status_code=200)
+
+
+@app.function_name(name="return_not_processed_last")
+@app.generic_trigger(arg_name="req", type="httpTrigger",
+                     route="return_not_processed_last")
+@app.generic_output_binding(arg_name="$return", type="http")
+@app.generic_input_binding(
+    arg_name="testEntities",
+    type="table",
+    connection="AzureWebJobsStorage",
+    table_name="EventHubBatchTest")
+def return_not_processed_last(req: func.HttpRequest, testEntities):
+    return func.HttpResponse(status_code=200)

tests/endtoend/generic_functions/return_not_processed_last/__init__.py

@@ -0,0 +1,13 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+import azure.functions as func
+
+
+# There are 3 bindings defined in function.json:
+# 1. req: HTTP trigger
+# 2. testEntities: table input (generic)
+# 3. $return: HTTP response
+# The bindings will be processed by the worker in this order:
+# req -> $return -> testEntities
+def main(req: func.HttpRequest, testEntities):
+    return func.HttpResponse(status_code=200)

tests/endtoend/generic_functions/return_not_processed_last/function.json

@@ -0,0 +1,26 @@
+{
+  "scriptFile": "__init__.py",
+  "bindings": [
+    {
+      "type": "httpTrigger",
+      "direction": "in",
+      "authLevel": "anonymous",
+      "methods": [
+        "get"
+      ],
+      "name": "req"
+    },
+    {
+      "direction": "in",
+      "type": "table",
+      "name": "testEntities",
+      "tableName": "EventHubBatchTest",
+      "connection": "AzureWebJobsStorage"
+    },
+    {
+      "type": "http",
+      "direction": "out",
+      "name": "$return"
+    }
+  ]
+}

tests/endtoend/generic_functions/return_processed_last/__init__.py

@@ -0,0 +1,13 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+import azure.functions as func
+
+
+# There are 3 bindings defined in function.json:
+# 1. req: HTTP trigger
+# 2. testEntity: table input (generic)
+# 3. $return: HTTP response
+# The bindings will be processed by the worker in this order:
+# req -> testEntity -> $return
+def main(req: func.HttpRequest, testEntity):
+    return func.HttpResponse(status_code=200)

tests/endtoend/generic_functions/return_processed_last/function.json

@@ -0,0 +1,26 @@
+{
+  "scriptFile": "__init__.py",
+  "bindings": [
+    {
+      "type": "httpTrigger",
+      "direction": "in",
+      "authLevel": "anonymous",
+      "methods": [
+        "get"
+      ],
+      "name": "req"
+    },
+    {
+      "direction": "in",
+      "type": "table",
+      "name": "testEntity",
+      "tableName": "EventHubBatchTest",
+      "connection": "AzureWebJobsStorage"
+    },
+    {
+      "type": "http",
+      "direction": "out",
+      "name": "$return"
+    }
+  ]
+}

tests/endtoend/test_generic_functions.py

@@ -0,0 +1,54 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+from unittest import skipIf
+
+from azure_functions_worker.utils.common import is_envvar_true
+from tests.utils import testutils
+from tests.utils.constants import DEDICATED_DOCKER_TEST, CONSUMPTION_DOCKER_TEST
+
+
+@skipIf(is_envvar_true(DEDICATED_DOCKER_TEST)
+        or is_envvar_true(CONSUMPTION_DOCKER_TEST),
+        "Table functions which are used in the bindings in these tests"
+        " has a bug with the table extension 1.0.0. "
+        "https://github.com/Azure/azure-sdk-for-net/issues/33902.")
+class TestGenericFunctions(testutils.WebHostTestCase):
+    """Test Generic Functions with implicit output enabled
+
+    With implicit output enabled for generic types, these tests cover
+    scenarios where a function has both explicit and implicit output
+    set to true. We prioritize explicit output. These tests check
+    that no matter the ordering, the return type is still correctly set.
+    """
+
+    @classmethod
+    def get_script_dir(cls):
+        return testutils.E2E_TESTS_FOLDER / 'generic_functions'
+
+    def test_return_processed_last(self):
+        # Tests the case where implicit and explicit return are true
+        # in the same function and $return is processed before
+        # the generic binding is
+
+        r = self.webhost.request('GET', 'return_processed_last')
+        self.assertEqual(r.status_code, 200)
+
+    def test_return_not_processed_last(self):
+        # Tests the case where implicit and explicit return are true
+        # in the same function and the generic binding is processed
+        # before $return
+
+        r = self.webhost.request('GET', 'return_not_processed_last')
+        self.assertEqual(r.status_code, 200)
+
+
+@skipIf(is_envvar_true(DEDICATED_DOCKER_TEST)
+        or is_envvar_true(CONSUMPTION_DOCKER_TEST),
+        "Table functions has a bug with the table extension 1.0.0."
+        "https://github.com/Azure/azure-sdk-for-net/issues/33902.")
+class TestGenericFunctionsStein(TestGenericFunctions):
+
+    @classmethod
+    def get_script_dir(cls):
+        return testutils.E2E_TESTS_FOLDER / 'generic_functions' / \
+            'generic_functions_stein'

tests/unittests/generic_functions/foobar_implicit_output_exemption/function.json

@@ -0,0 +1,12 @@
+{
+    "scriptFile": "main.py",
+    "bindings": [
+      {
+        "type": "durableClient",
+        "name": "input",
+        "direction": "in",
+        "dataType": "string"
+      }
+    ]
+  }
+

tests/unittests/generic_functions/foobar_implicit_output_exemption/main.py

@@ -0,0 +1,7 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+# Input as string, without annotation
+
+
+def main(input: str):
+    return input

tests/unittests/test_code_quality.py

@@ -36,7 +36,7 @@ def test_flake8(self):
         try:
             import flake8  # NoQA
         except ImportError as e:
-            raise unittest.SkipTest('flake8 moudule is missing') from e
+            raise unittest.SkipTest('flake8 module is missing') from e
 
         config_path = ROOT_PATH / '.flake8'
         if not config_path.exists():

tests/unittests/test_mock_generic_functions.py

@@ -119,7 +119,7 @@ async def test_mock_generic_as_bytes_no_anno(self):
                 protos.TypedData(bytes=b'\x00\x01')
             )
 
-    async def test_mock_generic_should_not_support_implicit_output(self):
+    async def test_mock_generic_should_support_implicit_output(self):
         async with testutils.start_mockhost(
                 script_root=self.generic_funcs_dir) as host:
 
@@ -131,7 +131,7 @@ async def test_mock_generic_should_not_support_implicit_output(self):
                              protos.StatusResult.Success)
 
             _, r = await host.invoke_function(
-                'foobar_as_bytes_no_anno', [
+                'foobar_implicit_output', [
                     protos.ParameterBinding(
                         name='input',
                         data=protos.TypedData(
@@ -140,10 +140,10 @@ async def test_mock_generic_should_not_support_implicit_output(self):
                     )
                 ]
             )
-            # It should fail here, since generic binding requires
-            # $return statement in function.json to pass output
+            # It passes now as we are enabling generic binding to return output
+            # implicitly
             self.assertEqual(r.response.result.status,
-                             protos.StatusResult.Failure)
+                             protos.StatusResult.Success)
 
     async def test_mock_generic_should_support_without_datatype(self):
         async with testutils.start_mockhost(
@@ -166,7 +166,32 @@ async def test_mock_generic_should_support_without_datatype(self):
                     )
                 ]
             )
-            # It should fail here, since the generic binding requires datatype
-            # to be defined in function.json
+            # It passes now as we are enabling generic binding to return output
+            # implicitly
+            self.assertEqual(r.response.result.status,
+                             protos.StatusResult.Success)
+
+    async def test_mock_generic_implicit_output_exemption(self):
+        async with testutils.start_mockhost(
+                script_root=self.generic_funcs_dir) as host:
+            await host.init_worker("4.17.1")
+            func_id, r = await host.load_function(
+                'foobar_implicit_output_exemption')
+            self.assertEqual(r.response.function_id, func_id)
+            self.assertEqual(r.response.result.status,
+                             protos.StatusResult.Success)
+
+            _, r = await host.invoke_function(
+                'foobar_implicit_output_exemption', [
+                    protos.ParameterBinding(
+                        name='input',
+                        data=protos.TypedData(
+                            bytes=b'\x00\x01'
+                        )
+                    )
+                ]
+            )
+            # It should fail here, since implicit output is False
+            # For the Durable Functions durableClient case
             self.assertEqual(r.response.result.status,
                              protos.StatusResult.Failure)