esbuild-runner (esr)

esbuild-runner (esr) is a high-speed on-the-fly transpiler for modern JavaScript, TypeScript, and JSX, powered by esbuild. It replaces slower alternatives like ts-node and babel-register for running scripts, tests, or arbitrary code without pre-building. Current version is 2.3.0-plugins.0, built on esbuild (peer dependency of any version). It offers two modes: bundling (default, one-shot esbuild invocation) and transform (file-by-file with caching via --cache flag). Useful for development workflows, Jest transforms, and VSCode debugging. Ships TypeScript definitions. No built-in plugins; the 'plugins' suffix indicates compatibility with esbuild plugins.