recommend-swc-over-babel

What This Rule Detects

This rule detects repositories using Babel that could benefit from migrating to SWC.

Why It Matters

SWC (Speedy Web Compiler) is a Rust-based compiler that provides:

• Significantly faster transpilation (often 10-20x faster than Babel)
• Native TypeScript support without additional plugins
• Faster CI/CD pipeline execution
• Lower memory footprint
• Drop-in replacement for standard Babel presets

Suggested Action

Consider migrating from Babel to SWC. The migration typically involves:

1. Install @swc/core and @swc/cli
2. Update your build scripts to use swc instead of babel
3. Convert Babel config to SWC config (.swcrc)

When This Rule Is Skipped

This rule will NOT recommend SWC if any of the following are detected:

• Custom Babel plugins: Projects using custom or third-party Babel plugins that may not have SWC equivalents
• babel-plugin-macros: SWC does not support the macros ecosystem
• Decorators (especially legacy): SWC’s decorator support differs from Babel’s, particularly for legacy decorators
• emotion Babel plugin: Requires @swc/plugin-emotion or @emotion/react with SWC compiler integration
• styled-components Babel plugin: Requires @swc/plugin-styled-components or styled-components compiler
• relay Babel plugin: Requires @swc/plugin-relay or relay compiler
• i18n extraction plugins: lingui, formatjs, i18next-extract, etc. have no direct SWC equivalents
• core-js / useBuiltIns: Polyfill strategy may need reconfiguration
• Legacy browser targets: IE11, old Chrome/Firefox/Safari versions may not be supported by SWC

These patterns indicate a higher migration risk that requires manual assessment.

Measurement

Compare transpilation time and output compatibility between Babel and SWC.

Compatibility Notes

• SWC is not a full drop-in replacement for Babel’s plugin ecosystem
• Standard presets (@babel/preset-env, @babel/preset-typescript, @babel/preset-react) map well to SWC
• SWC has growing plugin support via @swc/plugin-* packages
• Consider running SWC in parallel with Babel during migration to verify output