Fix recording content_type

CHANGES

@@ -1,3 +1,8 @@
+0.25.8
+------
+
+* Fix bug where the content type is always recorded as either text/plain or application/json. See #770
+
 0.25.7
 ------
 

responses/_recorder.py

@@ -26,6 +26,7 @@
 from responses import RequestsMock
 from responses import Response
 from responses import _real_send
+from responses import _UNSET
 from responses.registries import OrderedRegistry
 
 
@@ -153,6 +154,7 @@ def _on_request(
             status=requests_response.status_code,
             body=requests_response.text,
             headers=headers_values,
+            content_type=requests_response.headers.get("Content-Type", _UNSET),
         )
         self._registry.add(responses_response)
         return requests_response

responses/tests/test_recorder.py

@@ -58,7 +58,7 @@ def get_data(host, port):
                     "url": f"http://{host}:{port}/202",
                     "body": "OK",
                     "status": 202,
-                    "content_type": "text/plain",
+                    "content_type": "image/tiff",
                     "auto_calculate_content_length": False,
                 }
             },
@@ -132,7 +132,7 @@ def prepare_server(self, httpserver):
         httpserver.expect_request("/202").respond_with_data(
             "OK",
             status=202,
-            content_type="text/plain",
+            content_type="image/tiff",
         )
         httpserver.expect_request("/404").respond_with_data(
             "404 Not Found",