rolldown-plugin-wasm

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[![Unit Test][unit-test-src]][unit-test-href]

Rolldown plugin for WASM.

This project is heavily referenced from @rollup/plugin-wasm and vite-plugin-wasm.

Install

``bash
npm i rolldown-plugin-wasm
`

Usage

`ts
// rolldown.config.ts
import { defineConfig } from 'rolldown'
import { wasm } from 'rolldown-plugin-wasm'

export default defineConfig({
plugins: [
wasm({
// ...options
}),
],
})
`

$3

`ts
import { add } from './add.wasm'

add(1, 2)
`

$3

`ts
import init from './add.wasm?init'

const instance = await init(
imports, // optional
)

instance.exports.add(1, 2)
`

$3

`ts
import initSync from './add.wasm?init&sync'

const instance = initSync(
imports, // optional
)

instance.exports.add(1, 2)
`

$3

#### Target bundler (default, recommended)

`ts
import { add } from 'some-pkg'

add(1, 2)
`

#### Target web

##### Node.js

`ts
import { readFile } from 'node:fs/promises'
import init, { add } from 'some-pkg'
import wasmUrl from 'some-pkg/add_bg.wasm?url'

await init({
module_or_path: readFile(new URL(wasmUrl, import.meta.url)),
})

add(1, 2)
`

##### Browser

`ts
import init, { add } from 'some-pkg/add.js'
import wasmUrl from 'some-pkg/add_bg.wasm?url'

await init({
module_or_path: wasmUrl,
})

add(1, 2)
`

> [!NOTE]
> Other targets such as nodejs and no-modules are not supported.

$3

`jsonc
// tsconfig.json
{
"compilerOptions": {
"types": ["rolldown-plugin-wasm/types"],
},
}
`

Options

`ts
/**
* - "auto" will determine the environment at runtime and invoke the correct methods accordingly
* - "auto-inline" always inlines the WASM and will decode it according to the environment
* - "browser" omits emitting code that requires node.js builtin modules
* - "node" omits emitting code that requires fetch, but requires Node.js 20.16.0 or higher
*/
export type TargetEnv = 'auto' | 'auto-inline' | 'browser' | 'node'

export interface Options {
/**
* The maximum file size for inline files. If a file exceeds this limit, it will be copied to the destination folder and loaded from a separate file at runtime.
* If maxFileSize is set to 0 all files will be copied.
* Files specified in sync to load synchronously are always inlined, regardless of size.
*
@default 14 1024
*/
maxFileSize?: number
/**
* String used to rename the emitted Wasm files.
* @default '[hash][extname]'
*/
fileName?: string
/**
* A string which will be added in front of filenames when they are not inlined but are copied.
*/
publicPath?: string
/**
* Configures what code is emitted to instantiate the Wasm (both inline and separate)
*/
targetEnv?: TargetEnv
}
``

Sponsors

License

MIT License © 2026-PRESENT Kevin Deng

MIT Copyright (c) 2022 Menci

MIT License Copyright (c) 2019 RollupJS Plugin Contributors

[npm-version-src]: https://img.shields.io/npm/v/rolldown-plugin-wasm.svg
[npm-version-href]: https://npmjs.com/package/rolldown-plugin-wasm
[npm-downloads-src]: https://img.shields.io/npm/dm/rolldown-plugin-wasm
[npm-downloads-href]: https://www.npmcharts.com/compare/rolldown-plugin-wasm?interval=30
[unit-test-src]: https://github.com/sxzz/rolldown-plugin-wasm/actions/workflows/unit-test.yml/badge.svg
[unit-test-href]: https://github.com/sxzz/rolldown-plugin-wasm/actions/workflows/unit-test.yml