Broaden header JSON parsing error hardening

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

Author: cursoragent

hyperbrowser/header_utils.py

@@ -125,7 +125,9 @@ def parse_headers_env_json(raw_headers: Optional[str]) -> Optional[Dict[str, str
         return None
     try:
         parsed_headers = json.loads(raw_headers)
-    except (json.JSONDecodeError, ValueError, RecursionError, TypeError) as exc:
+    except HyperbrowserError:
+        raise
+    except Exception as exc:
         raise HyperbrowserError(
             "HYPERBROWSER_HEADERS must be valid JSON object",
             original_error=exc,

tests/test_header_utils.py

@@ -149,6 +149,36 @@ def _raise_recursion_error(_raw_headers: str):
     assert exc_info.value.original_error is not None
 
 
+def test_parse_headers_env_json_wraps_unexpected_json_errors(
+    monkeypatch: pytest.MonkeyPatch,
+):
+    def _raise_runtime_error(_raw_headers: str):
+        raise RuntimeError("unexpected json parser failure")
+
+    monkeypatch.setattr("hyperbrowser.header_utils.json.loads", _raise_runtime_error)
+
+    with pytest.raises(
+        HyperbrowserError, match="HYPERBROWSER_HEADERS must be valid JSON object"
+    ) as exc_info:
+        parse_headers_env_json('{"X-Trace-Id":"abc123"}')
+
+    assert exc_info.value.original_error is not None
+
+
+def test_parse_headers_env_json_preserves_hyperbrowser_json_errors(
+    monkeypatch: pytest.MonkeyPatch,
+):
+    def _raise_hyperbrowser_error(_raw_headers: str):
+        raise HyperbrowserError("custom header json failure")
+
+    monkeypatch.setattr("hyperbrowser.header_utils.json.loads", _raise_hyperbrowser_error)
+
+    with pytest.raises(HyperbrowserError, match="custom header json failure") as exc_info:
+        parse_headers_env_json('{"X-Trace-Id":"abc123"}')
+
+    assert exc_info.value.original_error is None
+
+
 def test_parse_headers_env_json_rejects_non_mapping_payload():
     with pytest.raises(
         HyperbrowserError,