@swc/core

What is @swc/core?

The @swc/core package is a super-fast compiler written in Rust that allows for transforming ECMAScript 2015+ code into a backwards compatible version of JavaScript that can be run in older browsers or environments. It is designed to be highly performant and offers features such as transpilation, minification, and source maps generation.

What are @swc/core's main functionalities?

JavaScript/TypeScript Transpilation

Transpiles TypeScript or modern JavaScript to a specified ECMAScript target version. This example demonstrates transpiling TypeScript code to ES5.

require('@swc/core').transformSync('const x: number = 1;', { jsc: { parser: { syntax: 'typescript' }, target: 'es5' } });

Code Minification

Minifies JavaScript code to reduce file size, which is beneficial for production environments. This example shows how to minify a simple expression.

require('@swc/core').transformSync('const x = 1 + 2;', { minify: true });

Source Maps

Generates source maps for the transformed code, aiding in debugging by mapping the transformed code back to the original source code. This example demonstrates generating a source map for a file named 'input.js'.

require('@swc/core').transformFileSync('input.js', { sourceMaps: true });

Other packages similar to @swc/core

babel-core

Babel is a widely used JavaScript compiler that also allows for transforming modern JavaScript into backward compatible versions. Compared to @swc/core, Babel is more established with a larger ecosystem of plugins, but @swc/core is known for its superior performance due to being written in Rust.

typescript

The TypeScript compiler not only provides type checking but also has the capability to transpile TypeScript code to JavaScript, similar to the transpilation feature of @swc/core. However, TypeScript does not focus on minification or other optimizations that @swc/core offers.

esbuild

Esbuild is a fast JavaScript bundler and minifier. It shares similar goals with @swc/core in terms of performance and efficiency. While both are focused on speed, esbuild emphasizes on bundling and has a different set of features compared to the more transpilation-focused @swc/core.

README

The README file is missing

Changelog

[1.6.3] - 2024-06-19

Bug Fixes

• (css/minifier) Don't tranform rotate deg (#9072) (8d37dae)

• (es/decorators) Reduce the number of sourcemap mappings (#9074) (cfe3ba3)

Performance

• (common) Use Chars in StringInput (#9073) (7698eaa)

• (es/lexer) Optimize lexer (#9075) (6426928)

• (es/lexer) Make lexing of string literals faster (#9077) (373bac5)

• (es/lexer) Reduce allocation while lexing identifiers (#9076) (69f00b8)

• (es/lexer) Add a fast-path to template literal lexer (#9080) (238f1c5)

• (es/lexer) Add fast-path to jsx lexer (#9081) (af58606)

Refactor

• (common) Simplify StringInput implementation (#9071) (c3a8c0b)