Improve JSON req error on disallowed empty body

connexion/validators/form_data.py

@@ -70,12 +70,13 @@ async def _parse(self, stream: t.AsyncGenerator[bytes, None], scope: Scope) -> d
 
         return data
 
-    def _validate(self, data: dict) -> None:
+    def _validate(self, body: t.Any) -> t.Optional[dict]:  # type: ignore[return]
+        if not isinstance(body, dict):
+            raise BadRequestProblem("Parsed body must be a mapping")
         if self._strict_validation:
-            self._validate_params_strictly(data)
-
+            self._validate_params_strictly(body)
         try:
-            self._validator.validate(data)
+            self._validator.validate(body)
         except ValidationError as exception:
             error_path_msg = format_error_with_path(exception=exception)
             logger.error(

connexion/validators/json.py

@@ -61,7 +61,9 @@ async def _parse(
         except json.decoder.JSONDecodeError as e:
             raise BadRequestProblem(detail=str(e))
 
-    def _validate(self, body: dict) -> None:
+    def _validate(self, body: t.Any) -> t.Optional[dict]:
+        if not self._nullable and body is None:
+            raise BadRequestProblem("Request body must not be empty")
         try:
             return self._validator.validate(body)
         except ValidationError as exception:

tests/api/test_errors.py

@@ -88,3 +88,10 @@ def test_errors(problem_app):
         "Invalid Content-type (text/html)"
     )
     assert unsupported_media_type_body["status"] == 415
+
+
+def test_should_raise_400_for_no_json(simple_app):
+    app_client = simple_app.test_client()
+    response = app_client.post("/v1.0/test-empty-object-body")
+    assert response.status_code == 400
+    assert response.json()["detail"] == "Request body must not be empty"