Validate env base URL resolver input type

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

Author: cursoragent

hyperbrowser/config.py

@@ -71,6 +71,8 @@ def parse_headers_from_env(raw_headers: Optional[str]) -> Optional[Dict[str, str
     def resolve_base_url_from_env(raw_base_url: Optional[str]) -> str:
         if raw_base_url is None:
             return "https://api.hyperbrowser.ai"
+        if not isinstance(raw_base_url, str):
+            raise HyperbrowserError("HYPERBROWSER_BASE_URL must be a string")
         if not raw_base_url.strip():
             raise HyperbrowserError("HYPERBROWSER_BASE_URL must not be empty when set")
         return ClientConfig.normalize_base_url(raw_base_url)

tests/test_config.py

@@ -290,6 +290,10 @@ def test_client_config_resolve_base_url_from_env_defaults_and_rejects_blank():
         ClientConfig.resolve_base_url_from_env("   ")
     with pytest.raises(HyperbrowserError, match="include a host"):
         ClientConfig.resolve_base_url_from_env("https://")
+    with pytest.raises(
+        HyperbrowserError, match="HYPERBROWSER_BASE_URL must be a string"
+    ):
+        ClientConfig.resolve_base_url_from_env(123)  # type: ignore[arg-type]
 
 
 def test_client_config_normalize_base_url_validates_and_normalizes():