Truncate oversized transport error messages

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

Author: cursoragent

hyperbrowser/transport/error_utils.py

@@ -5,6 +5,7 @@
 import httpx
 
 _HTTP_METHOD_TOKEN_PATTERN = re.compile(r"^[!#$%&'*+\-.^_`|~0-9A-Z]+$")
+_MAX_ERROR_MESSAGE_LENGTH = 2000
 
 
 def _normalize_request_method(method: Any) -> str:
@@ -31,6 +32,12 @@ def _normalize_request_url(url: Any) -> str:
     return normalized_url
 
 
+def _truncate_error_message(message: str) -> str:
+    if len(message) <= _MAX_ERROR_MESSAGE_LENGTH:
+        return message
+    return f"{message[:_MAX_ERROR_MESSAGE_LENGTH]}... (truncated)"
+
+
 def _stringify_error_value(value: Any, *, _depth: int = 0) -> str:
     if _depth > 10:
         return str(value)
@@ -71,8 +78,8 @@ def extract_error_message(response: httpx.Response, fallback_error: Exception) -
     def _fallback_message() -> str:
         response_text = response.text
         if isinstance(response_text, str) and response_text.strip():
-            return response_text
-        return str(fallback_error)
+            return _truncate_error_message(response_text)
+        return _truncate_error_message(str(fallback_error))
 
     try:
         error_data: Any = response.json()
@@ -95,7 +102,9 @@ def _fallback_message() -> str:
     else:
         extracted_message = _stringify_error_value(error_data)
 
-    return extracted_message if extracted_message.strip() else _fallback_message()
+    if not extracted_message.strip():
+        return _fallback_message()
+    return _truncate_error_message(extracted_message)
 
 
 def extract_request_error_context(error: httpx.RequestError) -> tuple[str, str]:

tests/test_transport_error_utils.py

@@ -281,3 +281,25 @@ def test_extract_error_message_skips_blank_message_and_uses_detail():
     )
 
     assert message == "useful detail"
+
+
+def test_extract_error_message_truncates_extracted_messages():
+    large_message = "x" * 2100
+    message = extract_error_message(
+        _DummyResponse({"message": large_message}),
+        RuntimeError("fallback detail"),
+    )
+
+    assert message.endswith("... (truncated)")
+    assert len(message) < len(large_message)
+
+
+def test_extract_error_message_truncates_fallback_response_text():
+    large_response_text = "y" * 2100
+    message = extract_error_message(
+        _DummyResponse("   ", text=large_response_text),
+        RuntimeError("fallback detail"),
+    )
+
+    assert message.endswith("... (truncated)")
+    assert len(message) < len(large_response_text)