Add stdio regression test for raw invalid UTF-8 tool arguments by raashish1601 · Pull Request #2369 · modelcontextprotocol/python-sdk

raashish1601 · 2026-03-28T13:09:36Z

Summary

add an end-to-end stdio regression for issue [Bug] Server crashes with anyio.ClosedResourceError when receiving raw invalid UTF-8 bytes #2328 using raw invalid UTF-8 bytes in a tools/call request
assert the server returns a JSON-RPC error response instead of crashing or dropping the reply on stdin EOF
exercise the existing stdio transport plus low-level server path without external server packages

PYTHONPATH=src python -m pytest -o addopts='' tests/issues/test_2328_stdio_invalid_utf8.py -q
PYTHONPATH=src python -m pytest -o addopts='' tests/server/test_stdio.py tests/issues/test_2328_stdio_invalid_utf8.py -q
python -m ruff check tests/issues/test_2328_stdio_invalid_utf8.py
git diff --check

raashish1601 added 2 commits March 28, 2026 18:35

Add regression test for invalid stdio UTF-8

c894c9e

test: cover delayed stdio EOF race

c492865

raashish1601 mentioned this pull request Mar 28, 2026

test: cover raw invalid UTF-8 stdio regression #2370

Closed

test: restore coverage for stdio invalid UTF-8 regression

08f7629