use-build

use-build is a bundler plugin help you to move logic and run it at build time

Usage

use use build directive to declare a build time file, in following code snippet, fetchMessage and zod schema validation is done at build time

// env.ts
"use build"

import { z } from "zod"
import { envSchema } from "./env-schema"

async function fetchMessage()
    console.log("should only run on build time")
    const delay = (ms: number) => new Promise(resolve => setTimeout(resolve, ms))
    await delay(1000)
    return "Hello world"
}

export const env = envSchema.parse(import.meta.env)

export const message = z.string().parse(await fetchMessage())

and you can use all export values by directly importing the build time file at runtime

import { useState } from "react"
import { container } from "./index.css"
import { message } from "./env"

export function Main() {
    const [count, setCount] = useState(0)

    return (
        <div className={container}>
            <button onClick={() => setCount(count => count + 1)}>count: {count}</button>
            <p>{message}</p>
        </div>
    )
}

Setup

npm install -D use-build

// vite.config.ts
import { defineConfig } from "vite"
import { UseBuildPlugin } from "use-build/vite"
import react from "@vitejs/plugin-react"

// https://vitejs.dev/config/
export default defineConfig({
    plugins: [react(), UseBuildPlugin()]
})

use-build currently supports:

• vite

• rsbuild

in development 🚧

• rspack

• rolldown

Caveat

All export values from build time file must be serializable.

Todo

• HMR

• Tests

• typescript plugins

Inspirations

GitHub - t3-oss/t3-env

GitHub - egoist/vite-plugin-compile-time: Some compile-time magic for your Vite project

License

MIT.