---
title: "Bun v1.2.20"
url: https://daily.dev/posts/bun-v1-2-20-jstzodqja
source_url: https://bun.com/blog/bun-v1.2.20
type: article
source: "Bun"
published: 2025-08-10T12:03:13.717Z
updated: 2025-08-10T12:03:37.740Z
tags: ["javascript", "testing", "nodejs", "webassembly", "bun"]
reading_time: 11
upvotes: 34
comments: 0
language: en
---

> ## Documentation Index
> Fetch the complete documentation index at: https://daily.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Bun v1.2.20

**[Bun](https://daily.dev/sources/bun)** · 11 min read · 34 upvotes · 0 comments

## Summary

Bun v1.2.20 fixes 141 issues and introduces significant performance improvements including reduced idle CPU usage and 40x faster AbortSignal.timeout. Key features include automatic yarn.lock migration to bun.lock, improved test diffing with new matchers like toHaveReturnedWith, TypeScript type testing with expectTypeOf, and WebAssembly streaming support. The release adds automatic ETag headers for static routes, Windows long path support, and enhanced workspace management with recursive flags for bun outdated and bun update commands.

## Full article

daily.dev links to this article rather than hosting it. Read it at the original source: <https://bun.com/blog/bun-v1.2.20>

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---

Tags: [#javascript](https://daily.dev/tags/javascript), [#testing](https://daily.dev/tags/testing), [#nodejs](https://daily.dev/tags/nodejs), [#webassembly](https://daily.dev/tags/webassembly), [#bun](https://daily.dev/tags/bun)

[View this post on daily.dev](https://daily.dev/posts/bun-v1-2-20-jstzodqja)