fix(e2e): start cache CI service and count bypass calls

.github/workflows/test-provider-cache.yml

@@ -24,7 +24,7 @@ jobs:
         ports:
           - 6379:6379
         options: >-
-          --health-cmd 'redis-cli ping'
+          --health-cmd "redis-cli ping"
           --health-interval 5s
           --health-timeout 3s
           --health-retries 10
@@ -35,10 +35,10 @@ jobs:
       E2E_PROVIDER_CACHE: '0'
       E2E_FIXTURE_MODE: live
     steps:
-      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955
+      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
         with:
           persist-credentials: false
-      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version: '3.13'
       - uses: ./.github/actions/setup-uv-with-retries
@@ -56,7 +56,7 @@ jobs:
           -q --junitxml=provider-cache-results.xml
       - name: Save test results
         if: always()
-        uses: actions/upload-artifact@4cec3d8aa04e39d1a68397de0c4cd6fb9dce8ec1
+        uses: actions/upload-artifact@4cec3d8aa04e39d1a68397de0c4cd6fb9dce8ec1 # v4.6.1
         with:
           name: provider-cache-results
           path: provider-cache-results.xml

tests/code_coverage_tests/test_provider_cache.py

@@ -11,8 +11,10 @@ from collections.abc import Generator
 from concurrent.futures import ThreadPoolExecutor
 from contextlib import contextmanager
 from dataclasses import dataclass, replace
+from http.client import HTTPConnection
 from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
 from typing import Final
+from urllib.parse import urlsplit
 
 import pytest
 from e2e_http import NetworkError, PreparedForward, RawResponse, StreamChunk, StreamHead, forward, prepare_forward
@@ -407,3 +409,24 @@ def test_enabled_environment_reuses_store_across_fresh_backends(
         assert configured_cache_backend() is None
     finally:
         configured_cache.cache_clear()
+
+
+def test_duplicate_headers_bypass_cache_and_count_live_calls(store: RedisResponseStore, provider: Provider) -> None:
+    cache: Final = CacheEdge(store, SECRET)
+    with edge(cache, provider) as url:
+        parsed: Final = urlsplit(url)
+        for _ in range(2):
+            connection = HTTPConnection(str(parsed.hostname), parsed.port, timeout=5)
+            try:
+                connection.putrequest("POST", parsed.path)
+                connection.putheader("content-length", str(len(BODY)))
+                connection.putheader("content-type", "application/json")
+                connection.putheader("x-duplicate", "first")
+                connection.putheader("x-duplicate", "second")
+                connection.endheaders(BODY)
+                assert connection.getresponse().read() == SUCCESS
+            finally:
+                connection.close()
+    assert len(provider.hits) == 2
+    assert dict(cache.counters.counts)["duplicate_header_bypass"] == 2
+    assert dict(cache.counters.counts)["upstream_attempts"] == 2

tests/e2e/provider_edge.py

@@ -891,6 +891,7 @@ class _EdgeHandler(BaseHTTPRequestHandler):
         )
         if isinstance(edge_server.backend, CacheEdge) and duplicate_headers:
             edge_server.backend.counters.increment("duplicate_header_bypass")
+            edge_server.backend.counters.increment("upstream_attempts")
         outcome: Final = handle_edge_request(
             selected_backend,
             edge_server.mounts,