Best of Bun — 2025

  1. 1
    Article
    Avatar of bunBun·21w

    Bun v1.3.5

    Bun v1.3.5 introduces a new Bun.Terminal API for pseudo-terminal (PTY) support, enabling interactive terminal applications. The release adds compile-time feature flags for dead-code elimination in the bundler, improves Bun.stringWidth accuracy for Unicode and emoji, and implements V8 C++ value type checking APIs. It also adds Content-Disposition support for S3 uploads and fixes environment variable expansion in .npmrc files. The update addresses 32 issues including networking bugs (macOS kqueue CPU usage, HTTP proxy authentication), Windows-specific crashes (WebSocket with compression, bunx panics), Node.js compatibility improvements, TypeScript definition fixes, and security issues with trusted dependencies.

  2. 2
    Article
    Avatar of bunBun·38w

    500x faster postMessage(string)

    Bun v1.2.21 introduces a zero-copy optimization for postMessage(string) that achieves up to 500x faster performance and 22x less memory usage by avoiding serialization for thread-safe strings. The optimization works by directly sharing immutable string pointers between threads in JavaScriptCore, bypassing the Structured Clone Algorithm for strings that aren't atoms, substrings, or rope strings. This dramatically improves performance for common patterns like sending JSON between workers, with the optimization automatically applying to strings over 256 characters.

  3. 3
    Article
    Avatar of bunBun·24w

    Bun v1.3.3

    Bun v1.3.3 fixes 95 issues and introduces several new features. Key additions include CompressionStream and DecompressionStream APIs with support for gzip, deflate, brotli, and zstd formats. Standalone executables now support flags to disable automatic .env and bunfig.toml loading. The test runner gains retry and repeats options for handling flaky tests. A new --no-env-file flag allows disabling automatic environment file loading. SQLite has been upgraded to version 3.51.0, and the runtime now uses Zig 0.15.2. The release includes numerous bug fixes across the bundler, package installer, Windows support, Node.js compatibility, Web APIs, networking, YAML parsing, and TypeScript definitions.

  4. 4
    Article
    Avatar of bunBun·34w

    Bun v1.2.22

    Bun v1.2.22 introduces async stack traces for better debugging, 240x faster postMessage and structuredClone for simple objects, and YAML stringify support. The release includes significant improvements to the MySQL adapter with affectedRows and lastInsertRowid support, better column type handling, and TLS connectivity. The bundler gains new minification optimizations, JSX side effects preservation, and an onEnd hook for plugins. Additional enhancements cover WebSocket subprotocol negotiation, Redis database selection, HTTP server idle connection management, event loop delay monitoring, and extensive Node.js compatibility fixes across child_process, crypto, N-API, and other modules.

  5. 5
    Article
    Avatar of bunBun·22w

    Bun v1.3.4

    Bun v1.3.4 fixes 194 issues and introduces several new features. The release adds URLPattern API for declarative URL matching, fake timers for the test runner to control time in tests, and custom proxy headers in fetch requests. It fixes a critical http.Agent connection pooling bug that prevented connection reuse. Standalone executables now skip loading config files at runtime by default for better performance. The update includes SQLite 3.51.1, console.log %j format specifier support, and numerous bugfixes across testing, bundler, Windows compatibility, Node.js APIs, and FFI.

  6. 6
    Article
    Avatar of bunBun·29w

    Bun v1.3.1

    Bun v1.3.1 fixes 103 issues with significant performance and feature improvements. Key updates include 2× faster builds on macOS for symlink-heavy projects, source maps preserving legal comments, and CommonJS format now inlining import.meta. The test runner adds Vitest's global vi, --pass-with-no-tests and --only-failures flags. Package management improvements include .npmrc email authentication support, faster installs without peer dependencies, and selective hoisting via publicHoistPattern/hoistPattern for isolated installs. Node.js compatibility enhancements include FileHandle.readLines() in fs/promises. Numerous bundler, transpiler, WebSocket, MySQL, and Windows-specific bugs are resolved.

  7. 7
    Article
    Avatar of bunBun·32w

    Bun v1.2.23

    Bun v1.2.23 introduces major improvements including pnpm-lock.yaml migration for seamless switching from pnpm, Redis Pub/Sub support, concurrent test execution with configurable parallelism, platform-specific dependency filtering, system CA certificates support, Windows code signing for compiled executables, JSX configuration improvements, SQL array helpers, randomized test ordering, and numerous Node.js compatibility fixes across http, dns, worker_threads, crypto, and other modules.

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