Sucrase

What Sucrase is

Sucrase is a free JavaScript transform tool for development builds aimed at modern JavaScript runtimes. It provides transforms for JSX, TypeScript, and Flow, along with imports, React hot loader code, and Jest. Its default JavaScript syntax transforms cover optional chaining, nullish coalescing, class fields, numeric separators, and optional catch binding. Sucrase strips TypeScript and Flow annotations but does not check types; a separate typechecker or linter is recommended. Developers can install it as an npm or Yarn development dependency, then use its CLI, Node require hook, ts-node plugin, or JavaScript API. Listed integrations include Webpack, Gulp, Jest, Rollup, and Broccoli, and it supports source maps. Sucrase targets modern runtimes rather than older browsers such as Internet Explorer, so unsupported syntax needs handling by the runtime or other tooling. Its transforms cannot be extended through plugins. The project describes Sucrase as most useful during development, while Babel or tsc may be a better fit for production builds. It is MIT-licensed and is available at no cost.

Who it suits

Sucrase suits developers who want quick transforms for modern JavaScript development builds, especially projects using JSX, TypeScript, or Flow. It is less suited to workflows that need type checking, older-browser compilation, or extensible transforms.

Getting started

1. Visit https://sucrase.io/.
2. Install Sucrase as an npm or Yarn development dependency.
3. Use it through the CLI, Node require hook, ts-node plugin, or JavaScript API.
4. Add a listed integration such as Webpack, Gulp, Jest, Rollup, or Broccoli if it fits your workflow.

Verdict

Choose Sucrase for development builds targeting modern JavaScript runtimes when its available transforms and integrations fit your project. Look elsewhere if you need type checking, old-browser output, extensible plugins, or a production-build tool better suited to that role.