What is babel-cli?
The babel-cli package provides a command line interface for Babel, a JavaScript compiler that allows you to use next generation JavaScript, today. It can transform your JavaScript files using Babel plugins and presets, making it easier to write modern JavaScript code that works in older environments.
What are babel-cli's main functionalities?
Transpile JavaScript files
This command transpiles all JavaScript files in the 'src' directory and outputs the transformed files into the 'lib' directory. It uses the Babel configuration specified in your project to determine how to transform the code.
babel src --out-dir lib
Watch files for changes
This command is similar to the previous one, but it also watches the 'src' directory for changes. Whenever a file is modified, Babel will automatically re-transpile the file and output the updated version to the 'lib' directory.
babel src --out-dir lib --watch
Specify presets and plugins
This command allows you to specify Babel presets and plugins directly in the command line. In this example, it uses the '@babel/preset-env' preset and the '@babel/plugin-transform-arrow-functions' plugin to transform the code.
babel src --out-dir lib --presets @babel/preset-env --plugins @babel/plugin-transform-arrow-functions
Other packages similar to babel-cli
typescript
TypeScript is a language that builds on JavaScript by adding static type definitions. The TypeScript compiler (tsc) can be used to transpile TypeScript code into JavaScript. Unlike Babel, TypeScript focuses on type safety and catching errors at compile time.
esbuild
esbuild is an extremely fast JavaScript bundler and minifier. It can also transpile modern JavaScript syntax to older versions. Compared to Babel, esbuild is much faster but may not support as many transformations and plugins.
swc
swc (Speedy Web Compiler) is a super-fast JavaScript/TypeScript compiler written in Rust. It aims to be a drop-in replacement for Babel with a focus on speed. While it supports many of the same transformations as Babel, it may not have as extensive a plugin ecosystem.