Wrap invalid filesystem path errors in file utility

Co-authored-by: Shri Sukhani <shrisukhani@users.noreply.github.com>

Author: cursoragent

hyperbrowser/client/file_utils.py

@@ -22,8 +22,18 @@ def ensure_existing_file_path(
         raise HyperbrowserError("file_path must resolve to a string path")
     if not normalized_path:
         raise HyperbrowserError("file_path must not be empty")
-    if not os.path.exists(normalized_path):
+    if "\x00" in normalized_path:
+        raise HyperbrowserError("file_path must not contain null bytes")
+    try:
+        path_exists = os.path.exists(normalized_path)
+    except (OSError, ValueError) as exc:
+        raise HyperbrowserError("file_path is invalid", original_error=exc) from exc
+    if not path_exists:
         raise HyperbrowserError(missing_file_message)
-    if not os.path.isfile(normalized_path):
+    try:
+        is_file = os.path.isfile(normalized_path)
+    except (OSError, ValueError) as exc:
+        raise HyperbrowserError("file_path is invalid", original_error=exc) from exc
+    if not is_file:
         raise HyperbrowserError(not_file_message)
     return normalized_path

tests/test_file_utils.py

@@ -2,6 +2,7 @@
 
 import pytest
 
+import hyperbrowser.client.file_utils as file_utils
 from hyperbrowser.client.file_utils import ensure_existing_file_path
 from hyperbrowser.exceptions import HyperbrowserError
 
@@ -79,3 +80,28 @@ def test_ensure_existing_file_path_rejects_empty_string_paths():
             missing_file_message="missing",
             not_file_message="not-file",
         )
+
+
+def test_ensure_existing_file_path_rejects_null_byte_paths():
+    with pytest.raises(
+        HyperbrowserError, match="file_path must not contain null bytes"
+    ):
+        ensure_existing_file_path(
+            "bad\x00path.txt",
+            missing_file_message="missing",
+            not_file_message="not-file",
+        )
+
+
+def test_ensure_existing_file_path_wraps_invalid_path_os_errors(monkeypatch):
+    def raising_exists(path: str) -> bool:
+        raise OSError("invalid path")
+
+    monkeypatch.setattr(file_utils.os.path, "exists", raising_exists)
+
+    with pytest.raises(HyperbrowserError, match="file_path is invalid"):
+        ensure_existing_file_path(
+            "/tmp/maybe-invalid",
+            missing_file_message="missing",
+            not_file_message="not-file",
+        )