esbuild-plugin-wasm

An asynchronous .wasm file loader for esbuild. This allows you to directly import .wasm files as if they were a javascript module, similar to how it works in Webpack.

This plugin follows the WebAssembly/ES Module Integration proposal for loading WebAssembly from a JavaScript import statement.

Requirements

• esbuild >= 0.11.0
• node >= 10.0.0

⚠️ Important Note ⚠️

This loader makes use of top-level await, which only has partial support in esbuild. For now, it is only supported with the esm output format, not the iife or cjs formats. See evanw/esbuild#253

Installation

npm install --save-dev esbuild-plugin-wasm

or

yarn add --dev esbuild-plugin-wasm

Usage

1. Add it to your esbuild plugins list

   CommonJS

   // build.js
   const esbuild = require('esbuild')
   const { wasmLoader } = require('esbuild-plugin-wasm')
   
   esbuild.build({
   ...
   plugins: [
       wasmLoader()
   ]
   ...
   });

   ESM

   // build.js
   import esbuild from 'esbuild'
   import { wasmLoader } from 'esbuild-plugin-wasm'
   
   esbuild.build({
   ...
   plugins: [
       wasmLoader()
   ]
   ...
   });

   Typescript

   // build.ts
   import esbuild from 'esbuild'
   import { wasmLoader } from 'esbuild-plugin-wasm'
   
   esbuild.build({
   ...
   plugins: [
       wasmLoader()
   ]
   ...
   });

2. Then import and use your wasm in your project

   ESM

   // app.js
   import wasm from "./lib.wasm";
   
   console(wasm.add(1, 2));

   Typescript

   // app.ts
   import wasm from "./lib.wasm";
   
   console(wasm.add(1, 2));

Configuration

wasmLoader({
    // (Default) Deferred mode copies the WASM binary to the output directory,
    // and then `fetch()`s it at runtime. This is the default mode.
    mode: 'deferred'

    // Embedded mode embeds the WASM binary in the javascript bundle as a
    // base64 string. Note this will greatly bloat the resulting bundle
    // (the binary will take up about 30% more space this way)
    mode: 'embedded'
})