Stabilize CI browser tests on macOS and Windows runners

- SE_SKIP_DRIVER_IN_PATH: runner images ship a chromedriver on PATH
  that lags the installed Chrome, so Selenium Manager picked a
  mismatched driver ('ChromeDriver only supports Chrome version 152')
  and macOS Chrome tests failed or were silently skipped
- Pass --no-sandbox/--disable-dev-shm-usage to every Requestium-launched
  Chrome in tests via own_chrome_session(), as the conftest drivers
  already did. On Windows runners, sandboxed Chrome for Testing
  (selected by selenium 4.32's Selenium Manager) silently drops
  navigations: measured 21/30 OK sandboxed vs 30/30 with --no-sandbox
- Widen test_session_default_timeout_is_used's margin; it missed by
  20ms on a slow Ubuntu runner

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01446x2ZH4bs3pKQ6mV84K1a

Author: lordjabez

.github/workflows/python.yml

@@ -66,6 +66,9 @@ jobs:
       - run: pytest -r A
         env:
           SE_AUTO_UPDATE: true # opt-in to selenium 5 behavior
+          # Runner images put a chromedriver on PATH that can lag the installed Chrome ("This version of
+          # ChromeDriver only supports Chrome version N"); let Selenium Manager resolve a matching driver instead.
+          SE_SKIP_DRIVER_IN_PATH: true
           COVERAGE_FILE: .coverage.${{ matrix.os }}.${{ matrix.python-version }}.${{ matrix.resolution }}
 
       - uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f

tests/conftest.py

@@ -7,7 +7,7 @@
 from collections.abc import Generator, Sequence
 from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
 from pathlib import Path
-from typing import TYPE_CHECKING, cast
+from typing import TYPE_CHECKING, Any, cast
 from urllib.parse import parse_qs, urlsplit
 
 import pytest
@@ -46,6 +46,11 @@
 DISABLE_HTTPS_UPGRADES = "--disable-features=HttpsUpgrades,HttpsFirstBalancedModeAutoEnable"
 
 
+# Chrome for Testing with its sandbox enabled silently dropped navigations on GitHub's Windows runners (driver.get returned but
+# the page stayed on data:, in 9 of 30 launches). The library must not disable the sandbox itself, so tests pass these.
+CHROME_CI_ARGUMENTS = ("--no-sandbox", "--disable-dev-shm-usage")
+
+
 class _Handler(BaseHTTPRequestHandler):
     """
     Serves pages and small JSON endpoints, and doubles as an HTTP forward proxy.
@@ -206,13 +211,20 @@ def chrome_options(server: LocalServer, *, headless: bool, arguments: Sequence[s
     options.add_argument(DISABLE_HTTPS_UPGRADES)
     for argument in arguments:
         options.add_argument(argument)
-    options.add_argument("--no-sandbox")
-    options.add_argument("--disable-dev-shm-usage")
+    for argument in CHROME_CI_ARGUMENTS:
+        options.add_argument(argument)
     if headless:
         options.add_argument("--headless=new")
     return options
 
 
+def own_chrome_session(*, arguments: Sequence[str] = (), **kwargs: Any) -> requestium.Session:  # noqa: ANN401
+    """Create a Session that starts its own Chrome with the CI-safe arguments, followed by any in webdriver_options and then arguments."""
+    webdriver_options = dict(kwargs.pop("webdriver_options", None) or {})
+    webdriver_options["arguments"] = [*CHROME_CI_ARGUMENTS, *webdriver_options.get("arguments", ()), *arguments]
+    return requestium.Session(webdriver_options=webdriver_options, **kwargs)
+
+
 def _create_chrome_driver(server: LocalServer, *, headless: bool) -> webdriver.Chrome:
     try:
         driver = webdriver.Chrome(options=chrome_options(server, headless=headless))

tests/test_add_cookie.py

@@ -14,7 +14,7 @@
 import requestium.requestium
 from requestium.requestium_mixin import DriverMixin
 
-from .conftest import LocalServer, assert_first_cookie_matches, chrome_options, cookies_sent_by_driver
+from .conftest import LocalServer, assert_first_cookie_matches, chrome_options, cookies_sent_by_driver, own_chrome_session
 
 
 def test_ensure_add_cookie(clean_session: requestium.Session, cookie_data: dict[str, str]) -> None:
@@ -63,12 +63,10 @@ def chrome(server: LocalServer) -> Generator[DriverMixin, None, None]:
 def secure_chrome(https_server: LocalServer) -> Generator[DriverMixin, None, None]:
     """Start Chrome with *.secure.com mapped to the TLS listener (a forward proxy can't tunnel to it) and its certificate trusted."""
     arguments = [
-        "--no-sandbox",
-        "--disable-dev-shm-usage",
         f"--host-resolver-rules=MAP *.secure.com 127.0.0.1:{https_server.port}",
         "--ignore-certificate-errors",
     ]
-    session = requestium.Session(headless=True, webdriver_options={"arguments": arguments})
+    session = own_chrome_session(headless=True, arguments=arguments)
     yield session.driver
     session.close()
 

tests/test_cookies.py

@@ -6,7 +6,7 @@
 
 import requestium.requestium
 
-from .conftest import LocalServer, assert_first_cookie_matches, cookies_sent_by_driver
+from .conftest import LocalServer, assert_first_cookie_matches, cookies_sent_by_driver, own_chrome_session
 
 # Cookie domains in these tests are fake public hostnames such as example.com. The browsers and requests are pointed at
 # the local server as an HTTP proxy (see LocalServer), so nothing leaves the machine, yet cookie and domain rules are
@@ -107,7 +107,7 @@ def test_transfer_session_cookies_to_driver_no_domain_error(clean_session: reque
 def localhost_session(server: LocalServer) -> Generator[requestium.Session, None, None]:
     """Start a Chrome session where http://localhost:<port> reaches the test server and counts as a secure context for Secure cookies."""
     arguments = ["--host-resolver-rules=MAP localhost 127.0.0.1", f"--unsafely-treat-insecure-origin-as-secure=http://localhost:{server.port}"]
-    session = requestium.Session(headless=True, webdriver_options={"arguments": ["--no-sandbox", "--disable-dev-shm-usage", *arguments]})
+    session = own_chrome_session(headless=True, arguments=arguments)
     yield session
     session.close()
 

tests/test_ensure_element.py

@@ -144,11 +144,12 @@ def test_session_default_timeout_is_used(session: requestium.Session) -> None:
         short_session = requestium.Session(driver=session.driver, default_timeout=0.6)
         assert short_session.driver.default_timeout == 0.6
 
-        run_later(short_session, "document.body.appendChild(Object.assign(document.createElement('div'), {id: 'slow'}));", delay_ms=1500)
+        run_later(short_session, "document.body.appendChild(Object.assign(document.createElement('div'), {id: 'slow'}));", delay_ms=3000)
         start = time.monotonic()
         with pytest.raises(TimeoutException):
             short_session.driver.ensure_element(By.ID, "slow")
-        assert 0.6 <= time.monotonic() - start < 1.4
+        # Well under the 3s it takes the element to appear, with headroom for slow CI runners
+        assert 0.6 <= time.monotonic() - start < 2.5
 
         # An explicit timeout overrides the default
         assert short_session.driver.ensure_element(By.ID, "slow", timeout=5) is not None

tests/test_proxy.py

@@ -6,13 +6,13 @@
 
 import requestium
 
-from .conftest import DISABLE_HTTPS_UPGRADES, LocalServer
+from .conftest import DISABLE_HTTPS_UPGRADES, LocalServer, own_chrome_session
 
 PROXIED_HOST = "requestium-proxy-test.invalid"
 
 
 def test_proxy_flag_reaches_chrome(server: LocalServer) -> None:
-    session = requestium.Session(headless=True, webdriver_options={"arguments": [DISABLE_HTTPS_UPGRADES]})
+    session = own_chrome_session(headless=True, arguments=[DISABLE_HTTPS_UPGRADES])
     try:
         # Set after construction but before the first driver access
         session.proxies = {"http": server.url}
@@ -35,7 +35,7 @@ def test_proxy_flag_format() -> None:
 
 
 def test_credentialed_proxy_warns_and_is_skipped() -> None:
-    session = requestium.Session(headless=True)
+    session = own_chrome_session(headless=True)
     session.proxies = {"http": "http://user:secret@proxy.example:8080"}
     try:
         with pytest.warns(UserWarning, match="credentials") as record:
@@ -46,7 +46,7 @@ def test_credentialed_proxy_warns_and_is_skipped() -> None:
 
 
 def test_no_warnings_without_credentials() -> None:
-    session = requestium.Session(headless=True)
+    session = own_chrome_session(headless=True)
     session.proxies = {"http": "http://proxy.example:8080"}
     with warnings.catch_warnings():
         warnings.simplefilter("error")

tests/test_session.py

@@ -13,7 +13,7 @@
 from requestium.requestium import DriverMixin, RequestiumResponse
 from requestium.requestium_session import _mixin_class
 
-from .conftest import LocalServer, chrome_options, validate_session
+from .conftest import LocalServer, chrome_options, own_chrome_session, validate_session
 
 SessionFactory = Callable[..., requestium.Session]
 
@@ -24,7 +24,7 @@ def make_session() -> Generator[SessionFactory, None, None]:
     sessions: list[requestium.Session] = []
 
     def _make_session(**kwargs: Any) -> requestium.Session:  # noqa: ANN401
-        session = requestium.Session(**kwargs)
+        session = own_chrome_session(**kwargs)
         sessions.append(session)
         return session
 
@@ -90,7 +90,7 @@ def driver_is_dead(driver: WebDriver) -> bool:
 
 
 def test_close_quits_lazily_started_chrome() -> None:
-    session = requestium.Session(headless=True)
+    session = own_chrome_session(headless=True)
     driver = session.driver
     assert not driver_is_dead(driver)
     session.close()
@@ -99,7 +99,7 @@ def test_close_quits_lazily_started_chrome() -> None:
 
 
 def test_close_then_driver_access_starts_fresh_chrome() -> None:
-    session = requestium.Session(headless=True)
+    session = own_chrome_session(headless=True)
     first = session.driver
     session.close()
     second = session.driver
@@ -111,20 +111,20 @@ def test_close_then_driver_access_starts_fresh_chrome() -> None:
 
 
 def test_context_manager_quits_driver() -> None:
-    with requestium.Session(headless=True) as session:
+    with own_chrome_session(headless=True) as session:
         driver = session.driver
         assert not driver_is_dead(driver)
     assert driver_is_dead(driver)
 
 
 def test_close_without_driver_does_not_start_one() -> None:
-    session = requestium.Session(headless=True)
+    session = own_chrome_session(headless=True)
     session.close()
     assert session._driver is None
 
 
 def test_close_twice_is_harmless() -> None:
-    session = requestium.Session(headless=True)
+    session = own_chrome_session(headless=True)
     driver = session.driver
     driver.quit()
     session.close()

tests/test_user_agent.py

@@ -4,7 +4,7 @@
 
 import requestium.requestium
 
-from .conftest import LocalServer
+from .conftest import LocalServer, own_chrome_session
 
 
 @pytest.fixture
@@ -55,7 +55,7 @@ def test_transfer_driver_cookies_to_session_can_skip_user_agent(reset_session_he
 
 
 def test_custom_user_agent_reaches_chrome() -> None:
-    session = requestium.Session(headless=True)
+    session = own_chrome_session(headless=True)
     session.headers["User-Agent"] = "RequestiumTest/1.0"
     try:
         assert session.driver.execute_script("return navigator.userAgent;") == "RequestiumTest/1.0"
@@ -64,7 +64,7 @@ def test_custom_user_agent_reaches_chrome() -> None:
 
 
 def test_default_user_agent_is_not_forced() -> None:
-    session = requestium.Session(headless=True)
+    session = own_chrome_session(headless=True)
     try:
         user_agent = session.driver.execute_script("return navigator.userAgent;")
         assert "python-requests" not in user_agent
@@ -73,7 +73,7 @@ def test_default_user_agent_is_not_forced() -> None:
 
 
 def test_user_supplied_user_agent_argument_wins() -> None:
-    session = requestium.Session(headless=True, webdriver_options={"arguments": ["--user-agent=FromOptions/2.0"]})
+    session = own_chrome_session(headless=True, arguments=["--user-agent=FromOptions/2.0"])
     session.headers["User-Agent"] = "FromHeaders/1.0"
     try:
         assert session.driver.execute_script("return navigator.userAgent;") == "FromOptions/2.0"