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 https://github.com/evanw/esbuild/issues/253

Installation

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

yarn add --dev esbuild-plugin-wasm

Usage

Add it to your esbuild plugins list

// build.ts
import esbuild from 'esbuild';
import wasmLoader from 'esbuild-plugin-wasm';

esbuild.build({
  ...
  plugins: [
    wasmLoader()
  ]
  ...
});

Then import your wasm

// 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 perffered 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'
})

npm