vite-plugin-wasm

Add WebAssembly ESM integration (aka. Webpack's asyncWebAssembly) to Vite and support wasm-pack generated modules.

Installation

This plugin supports Vite 2.x to 8.x. Just install it:

yarn add -D vite-plugin-wasm

Usage

You also need the vite-plugin-top-level-await plugin unless you target very modern browsers only (i.e. set build.target to esnext).

import wasm from "vite-plugin-wasm";
import topLevelAwait from "vite-plugin-top-level-await";

export default defineConfig({
  plugins: [
    wasm(),
    topLevelAwait()
  ]
});

If you are getting ESBuild errors of WASM files (In the format No loader is configured for ".wasm" files: node_modules/somepackage/somefile.wasm) with Vite < 3.0.3, please upgrade your Vite to >= 3.0.3 or upgrade this plugin to >= 3.1.0. A workaround is adding the corresponding imported module within node_modules to optimizeDeps.exclude, e.g.:

export default defineConfig({
  optimizeDeps: {
    exclude: [
      "@syntect/wasm"
    ]
  }
});

Web Worker

To use this plugin in Web Workers. Add it (and vite-plugin-top-level-await if necessary) to worker.plugins. To support Firefox, don't use ES workers. leave worker.format default and use vite-plugin-top-level-await >= 1.4.0 (see also here):

export default defineConfig({
  plugins: [
    wasm(),
    topLevelAwait()
  ],
  worker: {
    // Not needed with vite-plugin-top-level-await >= 1.3.0
    // format: "es",
    plugins: [
      wasm(),
      topLevelAwait()
    ]
  }
});

Notes

TypeScript typing is broken. Since we can't declare a module with Record<string, any> as its named export map, your import ... from "./module.wasm"; will still get Vite's built-in typing, but the transformed code is fine. Thus, you can simply use an asterisk import import * as wasmModule from "./module.wasm" and type assertion (you have typing for your WASM files, right?).