fix: Response content-length header needs to be recalculated if the response body is mutated in a post hook.

Author: EdgyEdgemond

src/starlette_problem/handler.py

@@ -106,6 +106,7 @@ def __call__(self: t.Self, request: Request, exc: Exception) -> Response:
 
         for post_hook in self.post_hooks:
             content, response = post_hook(content, request, response)
+            response.headers["content-length"] = str(len(response.body))
 
         return response
 

tests/test_handler.py

@@ -116,6 +116,7 @@ def test_strip_extras_post_hook_disabled(self):
             response.body
             == b'{"type":"something-wrong","title":"This is an error.","status":500,"a":"b","detail":"something bad"}'
         )
+        assert response.headers["content-length"] == "100"
 
     def test_strip_extras_post_hook_enabled(self):
         request = mock.Mock(headers={})
@@ -130,6 +131,7 @@ def test_strip_extras_post_hook_enabled(self):
             response.body
             == b'{"type":"something-wrong","title":"This is an error.","status":500,"detail":"something bad"}'
         )
+        assert response.headers["content-length"] == "92"
 
     def test_strip_extras_post_hook_exclude_status_code(self):
         request = mock.Mock(headers={})