Deflake http adaptor tests: retry route-not-ready 404s

hhenson · claude · hhenson · commit 02fb58ee45ba · 2026-07-18T06:20:46.000+04:00
The http_client adaptor test client retried connection failures but a
successful connection returning a 404 was recorded as the result. On a
slow CI runner the request can beat the handler graph's route
registration, so tornado returns its default not-found (HTTP 404, HTML
body) instead of the handler's 202/200 - failing the assertion
(observed on macOS-26 CI: test_http_server_handler_preserves_keyed_
auxiliary_outputs, [(404, b'&lt;html&gt;...')] != [(202, ...)]).

Retry a 404 up to the existing 10s deadline, same as a connection
error. Safe here because these tests never expect a 404. The REST
adaptor tests are deliberately left alone - they DO expect app-produced
404s (JSON bodies), distinguishable from the tornado default only by
body, and were not observed flaking.

Full tornado suite 42/42; full python suite 1258 passed / 19 skipped.

Co-Authored-By: Claude Opus 4.8 (1M context) &lt;noreply@anthropic.com&gt;
diff --git a/python/tests/adaptors/tornado/test_http_client_adaptor.py b/python/tests/adaptors/tornado/test_http_client_adaptor.py
@@ -334,6 +334,9 @@ def request(method, body=None):
                         },
                     )
                     response = connection.getresponse()
+                    if response.status == 404 and time.monotonic() < deadline:
+                        time.sleep(0.02)
+                        continue
                     responses.append(
                         {
                             "status": response.status,
@@ -455,6 +458,9 @@ def run():
                     try:
                         connection.request("GET", f"/handler-{free_tcp_port}/item")
                         response = connection.getresponse()
+                        if response.status == 404 and time.monotonic() < deadline:
+                            time.sleep(0.02)
+                            continue
                         client_result.append((response.status, response.read()))
                         break
                     except (ConnectionRefusedError, OSError):
@@ -534,6 +540,9 @@ def run():
                         try:
                             connection.request("GET", route)
                             response = connection.getresponse()
+                            if response.status == 404 and time.monotonic() < deadline:
+                                time.sleep(0.02)
+                                continue
                             client_results.append((response.status, response.read()))
                             break
                         except (ConnectionRefusedError, OSError):
@@ -620,6 +629,9 @@ def run():
                     try:
                         connection.request("GET", route)
                         response = connection.getresponse()
+                        if response.status == 404 and time.monotonic() < deadline:
+                            time.sleep(0.02)
+                            continue
                         client_results.append((response.status, response.read()))
                         break
                     except (ConnectionRefusedError, OSError):
