Require concrete exception text render outputs

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

Author: cursoragent

hyperbrowser/exceptions.py

@@ -21,13 +21,15 @@ def _safe_exception_text(value: Any, *, fallback: str) -> str:
         text_value = str(value)
     except Exception:
         return fallback
-    if not isinstance(text_value, str):
+    if type(text_value) is not str:
         return fallback
     try:
         sanitized_value = "".join(
             "?" if ord(character) < 32 or ord(character) == 127 else character
             for character in text_value
         )
+        if type(sanitized_value) is not str:
+            return fallback
         if sanitized_value.strip():
             return _truncate_exception_text(sanitized_value)
     except Exception:

tests/test_exceptions.py

@@ -98,3 +98,16 @@ def __str__(self) -> str:
         str(error)
         == "request failed - Caused by _BrokenOriginalError: <unstringifiable _BrokenOriginalError>"
     )
+
+
+def test_hyperbrowser_error_str_falls_back_for_string_subclass_str_results():
+    class _BrokenMessage:
+        class _SubclassString(str):
+            pass
+
+        def __str__(self) -> str:
+            return self._SubclassString("request failed")
+
+    error = HyperbrowserError(_BrokenMessage())  # type: ignore[arg-type]
+
+    assert str(error) == "Hyperbrowser error"