fix: prevent raw decoder from closing before sync completion

airbyte_cdk/sources/declarative/decoders/composite_raw_decoder.py

@@ -151,6 +151,10 @@ def decode(
         self, response: requests.Response
     ) -> Generator[MutableMapping[str, Any], None, None]:
         if self.is_stream_response():
+            # urllib mentions that some interfaces don't play nice with auto_close [here](https://urllib3.readthedocs.io/en/stable/user-guide.html#using-io-wrappers-with-response-content)
+            # We have indeed observed some issues with CSV parsing. Hence, we will manage the closing of the file ourselves until we find a better solution.
+            response.raw.auto_close = False
             yield from self.parser.parse(data=response.raw)  # type: ignore[arg-type]
+            response.raw.close()
         else:
             yield from self.parser.parse(data=io.BytesIO(response.content))

unit_tests/sources/declarative/decoders/test_composite_decoder.py

@@ -4,7 +4,10 @@
 import csv
 import gzip
 import json
+import socket
+from http.server import BaseHTTPRequestHandler, HTTPServer
 from io import BytesIO, StringIO
+from threading import Thread
 from unittest.mock import patch
 
 import pytest
@@ -20,6 +23,12 @@
 from airbyte_cdk.utils import AirbyteTracedException
 
 
+def find_available_port() -> int:
+    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+        s.bind(("localhost", 0))
+        return s.getsockname()[1]  # type: ignore  # this should return a int
+
+
 def compress_with_gzip(data: str, encoding: str = "utf-8"):
     """
     Compress the data using Gzip.
@@ -202,6 +211,39 @@ def test_composite_raw_decoder_csv_parser_values(requests_mock, encoding: str, d
     assert parsed_records == expected_data
 
 
+class TestServer(BaseHTTPRequestHandler):
+    def do_GET(self) -> None:
+        self.send_response(200)
+        self.end_headers()
+        self.wfile.write(bytes("col1,col2\nval1,val2", "utf-8"))
+
+
+def test_composite_raw_decoder_csv_parser_without_mocked_response():
+    """
+    This test reproduce a `ValueError: I/O operation on closed file` error we had with CSV parsing. We could not catch this with other tests because the closing of the mocked response from requests_mock was not the same as the one in requests.
+
+    We first identified this issue while working with the sample defined https://people.sc.fsu.edu/~jburkardt/data/csv/addresses.csv.
+    This should be reproducible by having the test server return the `self.wfile.write` statement as a comment below but it does not. However, it wasn't reproducible.
+
+    Currently we use `self.wfile.write(bytes("col1,col2\nval1,val2", "utf-8"))` to reproduce which we know is not a valid csv as it does not end with a newline character. However, this is the only we were able to reproduce locally.
+    """
+    # self.wfile.write(bytes('John,Doe,120 jefferson st.,Riverside, NJ, 08075\nJack,McGinnis,220 hobo Av.,Phila, PA,09119\n"John ""Da Man""",Repici,120 Jefferson St.,Riverside, NJ,08075\nStephen,Tyler,"7452 Terrace ""At the Plaza"" road",SomeTown,SD, 91234\n,Blankman,,SomeTown, SD, 00298\n"Joan ""the bone"", Anne",Jet,"9th, at Terrace plc",Desert City,CO,00123\n', "utf-8"))
+
+    # start server
+    port = find_available_port()
+    httpd = HTTPServer(("localhost", port), TestServer)
+    thread = Thread(target=httpd.serve_forever, args=())
+    thread.start()
+    try:
+        response = requests.get(f"http://localhost:{port}", stream=True)
+        result = list(CompositeRawDecoder(parser=CsvParser()).decode(response))
+
+        assert len(result) == 1
+    finally:
+        httpd.shutdown()  # release port and kill the thread
+        thread.join(timeout=5)  # ensure thread is cleaned up
+
+
 def test_given_response_already_consumed_when_decode_then_no_data_is_returned(requests_mock):
     requests_mock.register_uri(
         "GET", "https://airbyte.io/", content=json.dumps({"test": "test"}).encode()