Fix aiohttp ignore_localhost consuming response body

docs/changelog.rst

@@ -7,6 +7,9 @@ For a full list of triaged issues, bugs and PRs and what release they are target
 
 All help in providing PRs to close out bug issues is appreciated. Even if that is providing a repo that fully replicates issues. We have very generous contributors that have added these to bug issues which meant another contributor picked up the bug and closed it out.
 
+-  8.1.2
+    - Fix aiohttp ``ignore_localhost`` consuming response body, causing ``IncompleteReadError`` - thanks @AronsonDan
+
 -  8.1.1
     - Fix sync requests in async contexts for HTTPX (#965) - thanks @seowalex
     - CI: bump peter-evans/create-pull-request from 7 to 8 (#969)

tests/integration/test_aiohttp.py

@@ -500,3 +500,21 @@ def test_use_cassette_with_io(tmpdir, caplog, httpbin):
     with vcr.use_cassette(str(tmpdir.join("post.yaml"))):
         _, response_json = request("POST", url, output="json", data=data)
         assert response_json["data"] == "hello"
+
+
+@pytest.mark.online
+def test_ignore_localhost_does_not_consume_response_body(tmpdir, httpbin):
+    """When ignore_localhost=True, VCR should not consume the response body.
+
+    Previously, record_responses() would call response.read() to capture the
+    body before cassette.append() checked filter_request(). For ignored hosts,
+    the response was never saved but the body was already consumed, causing
+    IncompleteReadError for callers that later tried to read the response.
+    """
+    url = f"http://localhost:{httpbin.port}/get"
+
+    with vcr.use_cassette(str(tmpdir.join("ignore.yaml")), ignore_localhost=True) as cass:
+        response, response_text = get(url, output="text")
+        assert response.status == 200
+        assert len(response_text) > 0
+        assert len(cass) == 0

vcr/stubs/aiohttp_stubs.py

@@ -278,7 +278,8 @@ async def new_request(self, method, url, **kwargs):
         log.info("%s not in cassette, sending to real server", vcr_request)
 
         response = await real_request(self, method, url, **kwargs)
-        await record_responses(cassette, vcr_request, response)
+        if cassette.filter_request(vcr_request):
+            await record_responses(cassette, vcr_request, response)
         return response
 
     return new_request