Validate HYPERBROWSER_HEADERS value types before config init

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

Author: cursoragent

hyperbrowser/config.py

@@ -63,5 +63,12 @@ def from_env(cls) -> "ClientConfig":
                 raise HyperbrowserError(
                     "HYPERBROWSER_HEADERS must be a JSON object of string pairs"
                 )
+            if any(
+                not isinstance(key, str) or not isinstance(value, str)
+                for key, value in parsed_headers.items()
+            ):
+                raise HyperbrowserError(
+                    "HYPERBROWSER_HEADERS must be a JSON object of string pairs"
+                )
             headers = parsed_headers
         return cls(api_key=api_key, base_url=base_url, headers=headers)

tests/test_config.py

@@ -62,6 +62,17 @@ def test_client_config_from_env_rejects_non_object_headers_json(monkeypatch):
         ClientConfig.from_env()
 
 
+def test_client_config_from_env_rejects_non_string_header_values(monkeypatch):
+    monkeypatch.setenv("HYPERBROWSER_API_KEY", "test-key")
+    monkeypatch.setenv("HYPERBROWSER_HEADERS", '{"X-Request-Id":123}')
+
+    with pytest.raises(
+        HyperbrowserError,
+        match="HYPERBROWSER_HEADERS must be a JSON object of string pairs",
+    ):
+        ClientConfig.from_env()
+
+
 def test_client_config_from_env_ignores_blank_headers(monkeypatch):
     monkeypatch.setenv("HYPERBROWSER_API_KEY", "test-key")
     monkeypatch.setenv("HYPERBROWSER_HEADERS", "   ")