Added UT

Author: gavin-aguiar

azure_functions_worker/dispatcher.py

@@ -383,9 +383,12 @@ def load_function_metadata(self, function_app_directory, caller_info):
         function_path = os.path.join(function_app_directory,
                                      script_file_name)
 
-        self._function_metadata_result = (
-            self.index_functions(function_path, function_app_directory)) \
-            if os.path.exists(function_path) else None
+        if not os.path.exists(function_path):
+            raise FileNotFoundError("function_app.py not "
+                                    f"found in {function_path}")
+
+        self._function_metadata_result = self.index_functions(
+            function_path, function_app_directory)
 
     async def _handle__functions_metadata_request(self, request):
         metadata_request = request.functions_metadata_request

tests/unittests/test_dispatcher.py

@@ -915,6 +915,34 @@ def test_functions_metadata_request_with_indexing_exception(
             metadata_response.function_metadata_response.result.status,
             protos.StatusResult.Failure)
 
+    @patch.dict(os.environ, {PYTHON_ENABLE_INIT_INDEXING: 'false'})
+    def test_functions_metadata_request_with_filenotfound_exception(self):
+
+        request = protos.StreamingMessage(
+            worker_init_request=protos.WorkerInitRequest(
+                host_version="2.3.4",
+                function_app_directory=str(FUNCTION_APP_DIRECTORY)
+            )
+        )
+
+        metadata_request = protos.StreamingMessage(
+            functions_metadata_request=protos.FunctionsMetadataRequest(
+                function_app_directory="NonExistentDirectory"
+            )
+        )
+
+        self.loop.run_until_complete(
+            self.dispatcher._handle__worker_init_request(request))
+
+        metadata_response = self.loop.run_until_complete(
+            self.dispatcher._handle__functions_metadata_request(
+                metadata_request))
+
+        self.assertEqual(
+            metadata_response.function_metadata_response.result.exception.message,
+            "FileNotFoundError: function_app.py not "
+            "found in NonExistentDirectory\\function_app.py")
+
     @patch.dict(os.environ, {PYTHON_ENABLE_INIT_INDEXING: 'false'})
     def test_dispatcher_indexing_in_load_request(self):
         init_request = protos.StreamingMessage(