[py] Use pinned browser and driver for remote Grid tests instead of Selenium Manager

Author: titusfortner

py/conftest.py

@@ -16,6 +16,7 @@
 # under the License.
 
 import http.server
+import json
 import os
 import socketserver
 import sys
@@ -208,6 +209,43 @@ def _resolve_bazel_path(path):
     return path
 
 
+# Maps the test driver name to its (browserName, vendor options key).
+_GRID_VENDOR_OPTIONS = {
+    "chrome": ("chrome", "goog:chromeOptions"),
+    "edge": ("MicrosoftEdge", "ms:edgeOptions"),
+    "firefox": ("firefox", "moz:firefoxOptions"),
+}
+
+
+def _pinned_grid_args(config):
+    """Pin the driver and browser in a driver-configuration so the Grid node skips Selenium Manager.
+
+    Returns an empty list when nothing is pinned, keeping the default Selenium Manager behavior.
+    """
+    drivers_opt = config.option.drivers or []
+    driver = next((d for d in drivers_opt if d.lower() in _GRID_VENDOR_OPTIONS), None)
+    executable = config.option.executable  # --driver-binary
+    binary = config.option.binary  # --browser-binary
+    if not (driver and executable and binary):
+        return []
+
+    driver_path = _resolve_bazel_path(executable).strip("'")
+    browser_path = _resolve_bazel_path(binary).strip("'")
+    browser_name, vendor_key = _GRID_VENDOR_OPTIONS[driver.lower()]
+    stereotype = json.dumps({"browserName": browser_name, vendor_key: {"binary": browser_path}})
+    return [
+        "--enable-managed-downloads",
+        "true",
+        "--detect-drivers",
+        "false",
+        "--driver-configuration",
+        f"display-name={driver}",
+        "max-sessions=1",
+        f"webdriver-executable={driver_path}",
+        f"stereotype={stereotype}",
+    ]
+
+
 def get_extensions_location():
     """Locate the test extensions directory.
 
@@ -551,7 +589,7 @@ def server(request):
         # under Wayland, so we use XWayland instead.
         remote_env["MOZ_ENABLE_WAYLAND"] = "0"
 
-    server = Server(env=remote_env, startup_timeout=60)
+    server = Server(env=remote_env, startup_timeout=60, args=_pinned_grid_args(request.config) or None)
 
     repo_root = Path(__file__).parent.parent  # py/conftest.py -> py/ -> selenium/
     jar_path = "java/src/org/openqa/selenium/grid/selenium_server_deploy.jar"

py/selenium/webdriver/remote/server.py

@@ -44,8 +44,13 @@ class Server:
             Available levels: "SEVERE", "WARNING", "INFO", "CONFIG", "FINE", "FINER", "FINEST".
         env: Mapping that defines the environment variables for the server process.
         java_path: Path to the java executable to run the server.
+        args: Arguments for the standalone server command. Defaults to enabling Selenium
+            Manager and managed downloads; pass a list to override these entirely (e.g. to
+            pin drivers with "--driver-configuration").
     """
 
+    DEFAULT_ARGS = ("--selenium-manager", "true", "--enable-managed-downloads", "true")
+
     def __init__(
         self,
         host=None,
@@ -56,6 +61,7 @@ def __init__(
         env=None,
         java_path=None,
         startup_timeout=10,
+        args=None,
     ):
         if path and version:
             raise TypeError("Not allowed to specify a version when using an existing server path")
@@ -68,6 +74,7 @@ def __init__(
         self.env = env
         self.java_path = java_path
         self.startup_timeout = startup_timeout
+        self.args = list(args) if args is not None else list(self.DEFAULT_ARGS)
         self.process = None
 
     @property
@@ -190,10 +197,7 @@ def start(self):
             str(self.port),
             "--log-level",
             self.log_level,
-            "--selenium-manager",
-            "true",
-            "--enable-managed-downloads",
-            "true",
+            *self.args,
         ]
         if self.host is not None:
             command.extend(["--host", self.host])