@babel/core

What is @babel/core?

@babel/core is the core library of the Babel JavaScript compiler. It is primarily used for transforming ES6+ code into backwards compatible JavaScript that can be run by older JavaScript engines. Babel is widely used for its ability to transpile new JavaScript syntax, JSX, TypeScript, and for its plugin system that allows developers to use experimental features and customize the build process.

What are @babel/core's main functionalities?

Syntax Transformation

Transforms modern JavaScript syntax into a backwards compatible version. For example, it can convert ES6 arrow functions into regular ES5 functions.

require('@babel/core').transform('code', { presets: ['@babel/preset-env'] });

Plugin/Preset Application

Applies Babel plugins or presets to the code to enable specific transformations or sets of transformations.

require('@babel/core').transform('code', { plugins: ['@babel/plugin-transform-arrow-functions'] });

Source Map Generation

Generates source maps which help in debugging the original source code after it has been transformed by Babel.

require('@babel/core').transform('code', { sourceMaps: true });

Code Generation

Generates code from an Abstract Syntax Tree (AST). This is useful when you want to transform the AST directly or manipulate it before generating code.

require('@babel/core').transformFromAst(ast, 'code', { presets: ['@babel/preset-env'] });

Other packages similar to @babel/core

typescript

TypeScript is a superset of JavaScript that compiles to plain JavaScript. It offers type checking and is aimed at the development of large applications. While it does transpile code, it is more focused on type safety and less on new syntax features.

esbuild

esbuild is an extremely fast JavaScript bundler and minifier. It also provides a limited set of transformation features, such as JSX and TypeScript support. It is not as extensible as Babel but is focused on speed and efficiency.

swc

swc is a super-fast compiler written in Rust that aims to be a drop-in replacement for Babel. It supports most of the modern JavaScript features and is focused on performance. It is gaining popularity in the JavaScript community for its speed.

README

@babel/core

Babel compiler core.

See our website @babel/core for more information or the issues associated with this package.

Install

Using npm:

npm install --save-dev @babel/core

or using yarn:

yarn add @babel/core --dev

Changelog

v7.25.7 (2024-10-02)

:bug: Bug Fix

• babel-helper-validator-identifier
  • #16825 fix: update identifier to unicode 16 (@JLHwung)
• babel-traverse
  • #16814 fix: issue with node path keys updated on unrelated paths (@DylanPiercey)
• babel-plugin-transform-classes
  • #16797 Use an inclusion rather than exclusion list for super() check (@nicolo-ribaudo)
• babel-generator
  • #16788 Fix printing of TS infer in compact mode (@nicolo-ribaudo)
  • #16785 Print TS type annotations for destructuring in assignment pattern (@nicolo-ribaudo)
  • #16778 Respect [no LineTerminator here] after nodes (@nicolo-ribaudo)

:nail_care: Polish

• babel-types
  • #16852 Add deprecated JSDOC for fields (@liuxingbaoyu)

:house: Internal

• babel-core
  • #16820 Allow sync loading of ESM when --experimental-require-module (@nicolo-ribaudo)
• babel-helper-compilation-targets, babel-helper-plugin-utils, babel-preset-env
  • #16858 Add browserslist config to external dependency (@JLHwung)
• babel-plugin-proposal-destructuring-private, babel-plugin-syntax-decimal, babel-plugin-syntax-import-reflection, babel-standalone
  • #16809 Archive syntax-import-reflection and syntax-decimal (@nicolo-ribaudo)
• babel-generator
  • #16779 Simplify logic for [no LineTerminator here] before nodes (@nicolo-ribaudo)

:running_woman: Performance

• babel-plugin-transform-typescript
  • #16875 perf: Avoid extra cloning of namespaces (@liuxingbaoyu)
• babel-types
  • #16842 perf: Improve @babel/types builders (@liuxingbaoyu)
  • #16828 Only access BABEL_TYPES_8_BREAKING at startup (@nicolo-ribaudo)