automerge/javascript/examples/vite/README.md

Vite + Automerge

There are three things you need to do to get WASM packaging working with vite:

1. Install the top level await plugin
2. Install the vite-plugin-wasm plugin
3. Exclude automerge-wasm from the optimizer

First, install the packages we need:

yarn add vite-plugin-top-level-await
yarn add vite-plugin-wasm

In vite.config.js

import { defineConfig } from "vite"
import wasm from "vite-plugin-wasm"
import topLevelAwait from "vite-plugin-top-level-await"

export default defineConfig({
    plugins: [topLevelAwait(), wasm()],
    
    // This is only necessary if you are using `SharedWorker` or `WebWorker`, as 
    // documented in https://vitejs.dev/guide/features.html#import-with-constructors
    worker: { 
        format: "es",
        plugins: [topLevelAwait(), wasm()] 
    },

    optimizeDeps: {
        // This is necessary because otherwise `vite dev` includes two separate
        // versions of the JS wrapper. This causes problems because the JS
        // wrapper has a module level variable to track JS side heap
        // allocations, initializing this twice causes horrible breakage
        exclude: ["@automerge/automerge-wasm"]
    }
})

Now start the dev server:

yarn vite

Running the example

yarn install
yarn dev