[py] Properly verify Selenium Manager exists (#16711)

Author: cgoldberg

py/selenium/webdriver/common/selenium_manager.py

@@ -14,6 +14,7 @@
 # KIND, either express or implied.  See the License for the
 # specific language governing permissions and limitations
 # under the License.
+
 import json
 import logging
 import os
@@ -55,13 +56,20 @@ def binary_paths(self, args: list) -> dict:
 
     @staticmethod
     def _get_binary() -> Path:
-        """Determines the path of the correct Selenium Manager binary.
+        """Determines the path of the Selenium Manager binary.
+
+        Location of the binary is checked in this order:
+
+        1. location set in an environment variable
+        2. location where setuptools-rust places the compiled binary (built from the sdist package)
+        3. location where we ship binaries in the wheel package for the platform this is running on
+        4. give up
 
         Returns:
             The Selenium Manager executable location.
 
         Raises:
-            WebDriverException: If the platform is unsupported.
+            WebDriverException: If the platform is unsupported or Selenium Manager executable can't be found.
         """
         compiled_path = Path(__file__).parent.joinpath("selenium-manager")
         exe = sysconfig.get_config_var("EXE")
@@ -71,9 +79,12 @@ def _get_binary() -> Path:
         path: Path | None = None
 
         if (env_path := os.getenv("SE_MANAGER_PATH")) is not None:
-            logger.debug("Selenium Manager set by env SE_MANAGER_PATH to: %s", env_path)
-            path = Path(env_path)
-        elif compiled_path.exists():
+            logger.debug(f"Selenium Manager set by env SE_MANAGER_PATH to: {env_path}")
+            path_candidate = Path(env_path)
+            if not path_candidate.is_file():
+                raise WebDriverException(f"SE_MANAGER_PATH does not point to a file: {env_path}")
+            path = path_candidate
+        elif compiled_path.is_file():
             path = compiled_path
         else:
             allowed = {
@@ -87,7 +98,7 @@ def _get_binary() -> Path:
 
             arch = platform.machine() if sys.platform in ("linux", "freebsd", "openbsd") else "any"
             if sys.platform in ["freebsd", "openbsd"]:
-                logger.warning("Selenium Manager binary may not be compatible with %s; verify settings", sys.platform)
+                logger.warning(f"Selenium Manager binary may not be compatible with {sys.platform}; verify settings")
 
             location = allowed.get((sys.platform, arch))
             if location is None:
@@ -98,7 +109,7 @@ def _get_binary() -> Path:
         if path is None or not path.is_file():
             raise WebDriverException(f"Unable to obtain working Selenium Manager binary; {path}")
 
-        logger.debug("Selenium Manager binary found at: %s", path)
+        logger.debug(f"Selenium Manager binary found at: {path}")
 
         return path
 

py/test/selenium/webdriver/common/selenium_manager_tests.py

@@ -108,7 +108,7 @@ def test_error_if_invalid_env_path(monkeypatch):
 
     with pytest.raises(WebDriverException) as excinfo:
         SeleniumManager()._get_binary()
-    assert f"Unable to obtain working Selenium Manager binary; {sm_path}" in str(excinfo.value)
+    assert f"SE_MANAGER_PATH does not point to a file: {sm_path}" in str(excinfo.value)
 
 
 def test_run_successful():