v4.12.22

opengeos/geoaiv4.12.22May 22, 2026by yusukebe

AI Summary

This release updates the testing infrastructure to Vitest v4 and improves MIME handling, compression logic, and WebSocket protocol negotiation.

Key Highlights

Updated vitest to v4 and cleaned up test code
Improved MIME charset specification per MIME type
Compression now respects Accept-Encoding when encoding option is set
Added msgpack as a compressible content type

New Features

Msgpack support as a compressible content type

Full Release Notes

## What's Changed
* chore: update vitest to v4 and cleanups by @BlankParticle in https://github.com/honojs/hono/pull/4952
* fix(mime): specify charset parameter per MIME type instead of mechanical detection by @renatograsso10 in https://github.com/honojs/hono/pull/4912
* fix(compress): respect Accept-Encoding when encoding option is set by @LeSingh1 in https://github.com/honojs/hono/pull/4951
* fix(deno): echo negotiated WebSocket subprotocol in upgrade response by @ATOM00blue in https://github.com/honojs/hono/pull/4955
* feat: add msgpack as a compressible content type by @na-trium-144 in https://github.com/honojs/hono/pull/4957

## New Contributors
* @renatograsso10 made their first contribution in https://github.com/honojs/hono/pull/4912
* @LeSingh1 made their first contribution in https://github.com/honojs/hono/pull/4951
* @ATOM00blue made their first contribution in https://github.com/honojs/hono/pull/4955
* @na-trium-144 made their first contribution in https://github.com/honojs/hono/pull/4957

**Full Changelog**: https://github.com/honojs/hono/compare/v4.12.21...v4.12.22