fix: throw ValidationException instead of InvalidRequestContent when function name is invalid

Author: bchampp

samcli/local/lambda_service/lambda_error_responses.py

@@ -19,6 +19,9 @@ class LambdaErrorResponses:
     # The request body could not be parsed as JSON.
     InvalidRequestContentException = ("InvalidRequestContent", 400)
 
+    # One or more parameters values were invalid.
+    ValidationException = ("ValidationException", 400)
+
     NotImplementedException = ("NotImplemented", 501)
 
     ContainerCreationFailed = ("ContainerCreationFailed", 501)
@@ -85,6 +88,29 @@ def invalid_request_content(message):
             exception_tuple[1],
         )
 
+    @staticmethod
+    def validation_exception(message):
+        """
+        Creates a Lambda Service ValidationException Response
+
+        Parameters
+        ----------
+        message str
+            Message to be added to the body of the response
+
+        Returns
+        -------
+        Flask.Response
+            A response object representing the ValidationException Error
+        """
+        exception_tuple = LambdaErrorResponses.ValidationException
+
+        return BaseLocalService.service_response(
+            LambdaErrorResponses._construct_error_response_body(LambdaErrorResponses.USER_ERROR, message),
+            LambdaErrorResponses._construct_headers(exception_tuple[0]),
+            exception_tuple[1],
+        )
+
     @staticmethod
     def unsupported_media_type(content_type):
         """

samcli/local/lambda_service/local_lambda_invoke_service.py

@@ -172,7 +172,7 @@ def _invoke_request_handler(self, function_name):
             normalized_function_name = normalize_lambda_function_name(function_name)
         except InvalidFunctionNameException as e:
             LOG.error("Invalid function name: %s", str(e))
-            return LambdaErrorResponses.invalid_request_content(str(e))
+            return LambdaErrorResponses.validation_exception(str(e))
 
         stdout_stream_string = io.StringIO()
         stdout_stream_bytes = io.BytesIO()

tests/unit/local/lambda_service/test_lambda_error_responses.py

@@ -26,9 +26,18 @@ def test_invalid_request_content(self, service_response_mock):
         response = LambdaErrorResponses.invalid_request_content("InvalidRequestContent")
 
         self.assertEqual(response, "InvalidRequestContent")
+
+    @patch("samcli.local.services.base_local_service.BaseLocalService.service_response")
+    def test_validation_exception(self, service_response_mock):
+        service_response_mock.return_value = "ValidationException"
+
+        response = LambdaErrorResponses.validation_exception("ValidationException")
+
+        self.assertEqual(response, "ValidationException")
+
         service_response_mock.assert_called_once_with(
-            '{"Type": "User", "Message": "InvalidRequestContent"}',
-            {"x-amzn-errortype": "InvalidRequestContent", "Content-Type": "application/json"},
+            '{"Type": "User", "Message": "ValidationException"}',
+            {"x-amzn-errortype": "ValidationException", "Content-Type": "application/json"},
             400,
         )
 

tests/unit/local/lambda_service/test_local_lambda_invoke_service.py

@@ -379,6 +379,25 @@ def test_normalize_function_name_with_non_lambda_arn(self):
         with pytest.raises(InvalidFunctionNameException):
             normalize_lambda_function_name(s3_arn)
 
+    @patch("samcli.local.lambda_service.local_lambda_invoke_service.normalize_lambda_function_name")
+    @patch("samcli.local.lambda_service.local_lambda_invoke_service.LambdaErrorResponses")
+    def test_invoke_request_handler_with_invalid_function_name(self, lambda_error_responses_mock, normalize_mock):
+        """Test that InvalidFunctionNameException returns ValidationException"""
+        normalize_mock.side_effect = InvalidFunctionNameException("Invalid function name")
+        lambda_error_responses_mock.validation_exception.return_value = "ValidationException"
+
+        request_mock = Mock()
+        request_mock.get_data.return_value = b'{"key": "value"}'
+
+        lambda_runner_mock = Mock()
+        service = LocalLambdaInvokeService(lambda_runner=lambda_runner_mock, port=3001, host="127.0.0.1")
+
+        with patch("samcli.local.lambda_service.local_lambda_invoke_service.request", request_mock):
+            response = service._invoke_request_handler("invalid:function:name")
+
+        self.assertEqual(response, "ValidationException")
+        lambda_error_responses_mock.validation_exception.assert_called_once_with("Invalid function name")
+
     @patch("samcli.local.lambda_service.local_lambda_invoke_service.LocalLambdaInvokeService.service_response")
     @patch("samcli.local.lambda_service.local_lambda_invoke_service.LambdaOutputParser")
     def test_invoke_request_handler_with_arn(self, lambda_output_parser_mock, service_response_mock):