queryStringParameters set to None when there are no GET parameters

localstack/services/apigateway/apigateway_listener.py

@@ -334,7 +334,7 @@ def apply_request_parameters(
             if request_parameters.get(request_param_key, None) == request_param_value:
                 uri = uri.replace(f"{{{key}}}", path_params[key])
 
-    if integration.get("type") != "HTTP_PROXY" and request_parameters:
+    if integration.get("type") != "HTTP_PROXY" and request_parameters and query_params:
         for key in query_params.copy():
             request_query_key = f"integration.request.querystring.{key}"
             request_param_val = f"method.request.querystring.{key}"

localstack/services/apigateway/helpers.py

@@ -956,7 +956,7 @@ def extract_query_string_params(path: str) -> Tuple[str, Dict[str, str]]:
 
     # strip trailing slashes from path to fix downstream lookups
     path = path.rstrip("/") or "/"
-    return [path, query_string_params]
+    return [path, query_string_params or None]
 
 
 def get_cors_response(headers):

localstack/utils/http.py

@@ -90,7 +90,8 @@ def add_query_params_to_url(uri: str, query_params: Dict) -> str:
     query_dict = dict(parse_qsl(url.query))
 
     # updates the dict with new query parameters
-    query_dict.update(query_params)
+    if query_params:
+        query_dict.update(query_params)
 
     # encodes query parameters
     url_query = urlencode(query_dict)

tests/unit/test_apigateway.py

@@ -30,6 +30,10 @@ def test_extract_query_params(self):
         self.assertEqual("/foo/bar", path)
         self.assertEqual({"foo": "foo", "bar": ["bar", "baz"]}, query_params)
 
+        path, query_params = apigateway_listener.extract_query_string_params("/foo/bar")
+        self.assertEqual("/foo/bar", path)
+        self.assertEqual(None, query_params)
+
     def test_extract_path_params(self):
         params = apigateway_listener.extract_path_params("/foo/bar", "/foo/{param1}")
         self.assertEqual({"param1": "bar"}, params)