unplugin-macros

Macros are a mechanism for running JavaScript functions at bundle-time. The value returned from these functions or variables are directly inlined into your bundle.

Installation

# npm
npm i -D unplugin-macros

# jsr
npx jsr add -D @unplugin/macros

Vite

// vite.config.ts
import Macros from 'unplugin-macros/vite'

export default defineConfig({
  plugins: [Macros()],
})

Rollup

// rollup.config.js
import Macros from 'unplugin-macros/rollup'

export default {
  plugins: [Macros()],
}

esbuild

Requires esbuild >= 0.15

// esbuild.config.js
import { build } from 'esbuild'

build({
  plugins: [require('unplugin-macros/esbuild')()],
})

Webpack

// webpack.config.js
module.exports = {
  /* ... */
  plugins: [require('unplugin-macros/webpack')()],
}

Usage

// main.js
import { buildTime, getRandom } from './macros' with { type: 'macro' }

getRandom() // Will be replaced with a random number at build time
buildTime // Will be replaced with the timestamp at the build time

// macros.js
export function getRandom() {
  return Math.random()
}
export const buildTime = Date.now()

See more in Bun Macros.

TypeScript

Import Attributes syntax is supported in TypeScript 5.3 and above. However, you can use assert keyword instead of with, which is supported in TypeScript 4.5 and above.

ESLint

Import Attributes syntax is supported in ESLint v9.14.0.

Options

Refer to docs.

Thanks

Thanks to Bun Macros.

Sponsors

License

MIT License © 2023-PRESENT 三咲智子