Bun — JavaScript Runtime & Toolkit In-Depth Reference

Comprehensive reference for the Bun CLI (https://bun.sh/docs), covering the command reference, configuration, package manager, test runner, bundler, runtime API, shell, and module resolution. Bun is an all-in-one JavaScript runtime built on JavaScriptCore (not V8), with a native bundler, transpiler, test runner, and package manager written in Zig and C++.

Data Flow

Source file (.js/.ts/.jsx/.tsx)
  → transpiler (JS/TS/JSX → vanilla JS, dead code elimination)
    → module resolver (node_modules, exports field, tsconfig paths)
      → runtime (JavaScriptCore engine executes)
        → globals (Web API + Node.js + Bun-specific)
          → Bun API (serve, file, spawn, write, hash, etc.)

Sub-Resources

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