Read data from file-like objects in requests (#719)

responses/__init__.py

@@ -1054,6 +1054,21 @@ def _parse_request_params(
             params[key] = values
         return params
 
+    def _read_filelike_body(
+        self, body: Union[str, bytes, BufferedReader, None]
+    ) -> Union[str, bytes, None]:
+        # Requests/urllib support multiple types of body, including file-like objects.
+        # Read from the file if it's a file-like object to avoid storing a closed file
+        # in the call list and allow the user to compare against the data that was in the
+        # request.
+        # See GH #719
+        if isinstance(body, str) or isinstance(body, bytes) or body is None:
+            return body
+        # Based on https://github.com/urllib3/urllib3/blob/abbfbcb1dd274fc54b4f0a7785fd04d59b634195/src/urllib3/util/request.py#L220
+        if hasattr(body, "read"):
+            return body.read()  # type: ignore[attr-defined]
+        return body  # type: ignore[no-any-return]
+
     def _on_request(
         self,
         adapter: "HTTPAdapter",
@@ -1067,6 +1082,7 @@ def _on_request(
         request.params = self._parse_request_params(request.path_url)  # type: ignore[attr-defined]
         request.req_kwargs = kwargs  # type: ignore[attr-defined]
         request_url = str(request.url)
+        request.body = self._read_filelike_body(request.body)
 
         match, match_failed_reasons = self._find_match(request)
         resp_callback = self.response_callback

responses/tests/test_responses.py

@@ -2708,3 +2708,23 @@ def run():
 
     run()
     assert_reset()
+
+
+def test_file_like_body_in_request():
+    """Validate that when file-like objects are used in requests the data can be accessed
+    in the call list. This ensures that we are not storing file handles that may be closed
+    by the time the user wants to assert on the data in the request. GH #719.
+    """
+
+    @responses.activate
+    def run():
+        responses.add(responses.POST, "https://example.com")
+        with tempfile.TemporaryFile() as f:
+            f.write(b"test")
+            f.seek(0)
+            requests.post("https://example.com", data=f)
+        assert len(responses.calls) == 1
+        assert responses.calls[0].request.body == b"test"
+
+    run()
+    assert_reset()