Bun

The v1.3.x series ran through v1.3.14, shipping test infrastructure, native APIs, and package manager work across each release.¹

bun test gained CI-grade tooling — --isolate, --parallel, --shard, and --changed flags added full test isolation, worker-based parallelism, CI sharding with Jest/Vitest syntax compatibility, and git-aware file filtering.²

Package installation became substantially cheaper: streaming tarball extraction cut memory usage by 17x, and the isolated linker reduced install time from 20.5s to 2.4s in peer-heavy monorepos.³

New native platform APIs shipped in v1.3.12:⁴

• Bun.WebView — a headless browser API with WebKit (macOS) and Chrome backends, dispatching OS-level events
• Bun.cron() for in-process scheduled tasks
• Direct Markdown-to-ANSI terminal rendering via bun ./file.md

The REPL was rewritten in Zig in v1.3.10, adding syntax highlighting, persistent history, and tab completion.⁵ Windows ARM64 support, TC39 standard decorator support (including accessor and Symbol.metadata), and self-contained HTML bundles via --compile --target=browser landed in the same release.

Source maps switched to a bit-packed binary format using 8x less memory, and gzip compression accelerated 5.5x via zlib-ng 2.3.3.⁶ A request smuggling fix and HTTP response splitting patch landed across the series.