fix(event-handler): multi-value query string and validation of scalar parameters (#3795)

Author: rubenfonseca

aws_lambda_powertools/event_handler/middlewares/openapi_validation.py

@@ -368,7 +368,10 @@ def _get_embed_body(
     return received_body, field_alias_omitted
 
 
-def _normalize_multi_query_string_with_param(query_string: Optional[Dict[str, str]], params: Sequence[ModelField]):
+def _normalize_multi_query_string_with_param(
+    query_string: Dict[str, List[str]],
+    params: Sequence[ModelField],
+) -> Dict[str, Any]:
     """
     Extract and normalize resolved_query_string_parameters
 
@@ -383,15 +386,15 @@ def _normalize_multi_query_string_with_param(query_string: Optional[Dict[str, st
     -------
     A dictionary containing the processed multi_query_string_parameters.
     """
-    if query_string:
-        for param in filter(is_scalar_field, params):
-            try:
-                # if the target parameter is a scalar, we keep the first value of the query string
-                # regardless if there are more in the payload
-                query_string[param.alias] = query_string[param.alias][0]
-            except KeyError:
-                pass
-    return query_string
+    resolved_query_string: Dict[str, Any] = query_string
+    for param in filter(is_scalar_field, params):
+        try:
+            # if the target parameter is a scalar, we keep the first value of the query string
+            # regardless if there are more in the payload
+            resolved_query_string[param.alias] = query_string[param.alias][0]
+        except KeyError:
+            pass
+    return resolved_query_string
 
 
 def _normalize_multi_header_values_with_param(headers: Optional[Dict[str, str]], params: Sequence[ModelField]):

aws_lambda_powertools/utilities/data_classes/alb_event.py

@@ -36,11 +36,11 @@ def multi_value_query_string_parameters(self) -> Optional[Dict[str, List[str]]]:
         return self.get("multiValueQueryStringParameters")
 
     @property
-    def resolved_query_string_parameters(self) -> Optional[Dict[str, Any]]:
+    def resolved_query_string_parameters(self) -> Dict[str, List[str]]:
         if self.multi_value_query_string_parameters:
             return self.multi_value_query_string_parameters
 
-        return self.query_string_parameters
+        return super().resolved_query_string_parameters
 
     @property
     def resolved_headers_field(self) -> Optional[Dict[str, Any]]:

aws_lambda_powertools/utilities/data_classes/api_gateway_proxy_event.py

@@ -119,11 +119,11 @@ def multi_value_query_string_parameters(self) -> Optional[Dict[str, List[str]]]:
         return self.get("multiValueQueryStringParameters")
 
     @property
-    def resolved_query_string_parameters(self) -> Optional[Dict[str, Any]]:
+    def resolved_query_string_parameters(self) -> Dict[str, List[str]]:
         if self.multi_value_query_string_parameters:
             return self.multi_value_query_string_parameters
 
-        return self.query_string_parameters
+        return super().resolved_query_string_parameters
 
     @property
     def resolved_headers_field(self) -> Optional[Dict[str, Any]]:
@@ -318,16 +318,6 @@ def http_method(self) -> str:
     def header_serializer(self):
         return HttpApiHeadersSerializer()
 
-    @property
-    def resolved_query_string_parameters(self) -> Optional[Dict[str, Any]]:
-        if self.query_string_parameters is not None:
-            query_string = {
-                key: value.split(",") if "," in value else value for key, value in self.query_string_parameters.items()
-            }
-            return query_string
-
-        return {}
-
     @property
     def resolved_headers_field(self) -> Optional[Dict[str, Any]]:
         if self.headers is not None:

aws_lambda_powertools/utilities/data_classes/bedrock_agent_event.py

@@ -109,10 +109,6 @@ def query_string_parameters(self) -> Optional[Dict[str, str]]:
         # together with the other parameters. So we just return all parameters here.
         return {x["name"]: x["value"] for x in self["parameters"]} if self.get("parameters") else None
 
-    @property
-    def resolved_query_string_parameters(self) -> Optional[Dict[str, str]]:
-        return self.query_string_parameters
-
     @property
     def resolved_headers_field(self) -> Optional[Dict[str, Any]]:
         return {}

aws_lambda_powertools/utilities/data_classes/common.py

@@ -104,15 +104,19 @@ def query_string_parameters(self) -> Optional[Dict[str, str]]:
         return self.get("queryStringParameters")
 
     @property
-    def resolved_query_string_parameters(self) -> Optional[Dict[str, str]]:
+    def resolved_query_string_parameters(self) -> Dict[str, List[str]]:
         """
         This property determines the appropriate query string parameter to be used
         as a trusted source for validating OpenAPI.
 
         This is necessary because different resolvers use different formats to encode
         multi query string parameters.
         """
-        return self.query_string_parameters
+        if self.query_string_parameters is not None:
+            query_string = {key: value.split(",") for key, value in self.query_string_parameters.items()}
+            return query_string
+
+        return {}
 
     @property
     def resolved_headers_field(self) -> Optional[Dict[str, Any]]:
@@ -186,17 +190,15 @@ def get_header_value(
         name: str,
         default_value: str,
         case_sensitive: Optional[bool] = False,
-    ) -> str:
-        ...
+    ) -> str: ...
 
     @overload
     def get_header_value(
         self,
         name: str,
         default_value: Optional[str] = None,
         case_sensitive: Optional[bool] = False,
-    ) -> Optional[str]:
-        ...
+    ) -> Optional[str]: ...
 
     def get_header_value(
         self,

aws_lambda_powertools/utilities/data_classes/vpc_lattice.py

@@ -73,17 +73,15 @@ def get_header_value(
         name: str,
         default_value: str,
         case_sensitive: Optional[bool] = False,
-    ) -> str:
-        ...
+    ) -> str: ...
 
     @overload
     def get_header_value(
         self,
         name: str,
         default_value: Optional[str] = None,
         case_sensitive: Optional[bool] = False,
-    ) -> Optional[str]:
-        ...
+    ) -> Optional[str]: ...
 
     def get_header_value(
         self,
@@ -140,10 +138,6 @@ def query_string_parameters(self) -> Dict[str, str]:
         """The request query string parameters."""
         return self["query_string_parameters"]
 
-    @property
-    def resolved_query_string_parameters(self) -> Optional[Dict[str, str]]:
-        return self.query_string_parameters
-
     @property
     def resolved_headers_field(self) -> Optional[Dict[str, Any]]:
         if self.headers is not None:
@@ -255,17 +249,21 @@ def path(self) -> str:
 
     @property
     def request_context(self) -> vpcLatticeEventV2RequestContext:
-        """he VPC Lattice v2 Event request context."""
+        """The VPC Lattice v2 Event request context."""
         return vpcLatticeEventV2RequestContext(self["requestContext"])
 
     @property
     def query_string_parameters(self) -> Optional[Dict[str, str]]:
-        """The request query string parameters."""
-        return self.get("queryStringParameters")
+        """The request query string parameters.
 
-    @property
-    def resolved_query_string_parameters(self) -> Optional[Dict[str, str]]:
-        return self.query_string_parameters
+        For VPC Lattice V2, the queryStringParameters will contain a Dict[str, List[str]]
+        so to keep compatibility with existing utilities, we merge all the values with a comma.
+        """
+        params = self.get("queryStringParameters")
+        if params:
+            return {key: ",".join(value) for key, value in params.items()}
+        else:
+            return None
 
     @property
     def resolved_headers_field(self) -> Optional[Dict[str, str]]:

tests/functional/event_handler/conftest.py

@@ -2,6 +2,8 @@
 
 import pytest
 
+from tests.functional.utils import load_event
+
 
 @pytest.fixture
 def json_dump():
@@ -39,3 +41,33 @@ def validation_schema():
 @pytest.fixture
 def raw_event():
     return {"message": "hello hello", "username": "blah blah"}
+
+
+@pytest.fixture
+def gw_event():
+    return load_event("apiGatewayProxyEvent.json")
+
+
+@pytest.fixture
+def gw_event_http():
+    return load_event("apiGatewayProxyV2Event.json")
+
+
+@pytest.fixture
+def gw_event_alb():
+    return load_event("albMultiValueQueryStringEvent.json")
+
+
+@pytest.fixture
+def gw_event_lambda_url():
+    return load_event("lambdaFunctionUrlEventWithHeaders.json")
+
+
+@pytest.fixture
+def gw_event_vpc_lattice():
+    return load_event("vpcLatticeV2EventWithHeaders.json")
+
+
+@pytest.fixture
+def gw_event_vpc_lattice_v1():
+    return load_event("vpcLatticeEvent.json")