vite.config.js

// vite.config.js
import { defineConfig } from 'vite';
import wasm from 'vite-plugin-wasm';
import topLevelAwait from 'vite-plugin-top-level-await';

// Set modern build target so top-level await in dependencies (e.g. three/examples WebGPU helper)
// doesn't get transformed to an unsupported lower target during bundle/transpile.
export default defineConfig({
  plugins: [
    wasm(),
    topLevelAwait()
  ],
  base: './',
  build: {
    target: 'es2022',
    // Ensures assets don't get lost in complex folder structures
    assetsDir: './',
    // Restrict rollup input to only the app's root index.html so Vite doesn't try to
    // analyze unrelated HTML files (like those under emsdk/tests) which can import
    // non-app modules such as loader.mjs.
    rollupOptions: {
      input: {
        main: './index.html'
      }
    }
  },
  esbuild: {
    // ensure esbuild treats code as modern so top-level await is preserved
    target: 'es2022'
  },
  // Ensure optimizeDeps only scans the app root entry (index.html) and targets
  // modern JS (esnext) so top-level await in dependencies is preserved.
  optimizeDeps: {
    // Force dependency scanning to the app's root index -- don't scan test HTML files
    // inside emsdk or other bundles which can include non-app imports.
    entries: ['./index.html'],
    esbuildOptions: {
      target: 'esnext'
    }
  },
  server: {
    headers: {
      // These headers are REQUIRED for SharedArrayBuffer (Pthreads)
      'Cross-Origin-Opener-Policy': 'same-origin',
      'Cross-Origin-Embedder-Policy': 'require-corp',
    },
    // Keep Vite from serving files outside the repository root by default.
    fs: {
      strict: true
    },
    // Ignore the emsdk test folder (these are unrelated test HTML files that can
    // confuse Vite's dependency scanner and cause unresolved import errors).
    watch: {
      ignored: ['**/emsdk/**']
    }
  },
  // Ensure the worker file is treated correctly if using Vite's worker import (optional but safe)
  worker: {
    format: 'es',
    plugins: () => [
      wasm(),
      topLevelAwait()
    ]
  }
});