Reject empty direct API key values in client config

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

Author: cursoragent

hyperbrowser/config.py

@@ -21,6 +21,8 @@ def __post_init__(self) -> None:
         if self.headers is not None and not isinstance(self.headers, dict):
             raise HyperbrowserError("headers must be a dictionary of string pairs")
         self.api_key = self.api_key.strip()
+        if not self.api_key:
+            raise HyperbrowserError("api_key must not be empty")
         self.base_url = self.base_url.strip().rstrip("/")
         if not self.base_url:
             raise HyperbrowserError("base_url must not be empty")

tests/test_config.py

@@ -64,6 +64,9 @@ def test_client_config_rejects_non_string_values():
     with pytest.raises(HyperbrowserError, match="headers must be a dictionary"):
         ClientConfig(api_key="test-key", headers="x=1")  # type: ignore[arg-type]
 
+    with pytest.raises(HyperbrowserError, match="api_key must not be empty"):
+        ClientConfig(api_key="   ")
+
 
 def test_client_config_rejects_empty_or_invalid_base_url():
     with pytest.raises(HyperbrowserError, match="base_url must not be empty"):