vite.config.mjs

import { svelte }          from '@sveltejs/vite-plugin-svelte';
import resolve             from '@rollup/plugin-node-resolve'; // This resolves NPM modules from node_modules.
import preprocess          from 'svelte-preprocess';
import {
   postcssConfig,
   terserConfig }          from '@typhonjs-fvtt/runtime/rollup';

// ATTENTION!
// Please modify the below variables: s_PACKAGE_ID and s_SVELTE_HASH_ID appropriately.

// For convenience, you just need to modify the package ID below as it is used to fill in default proxy settings for
// the dev server.
const s_PACKAGE_ID = 'modules/autoanimations';

// A short additional string to add to Svelte CSS hash values to make yours unique. This reduces the amount of
// duplicated framework CSS overlap between many TRL packages enabled on Foundry VTT at the same time.
const s_SVELTE_HASH_ID = 'auto';

const s_COMPRESS = false;  // Set to true to compress the module bundle.
const s_SOURCEMAPS = true; // Generate sourcemaps for the bundle (recommended).

// Used in bundling.
const s_RESOLVE_CONFIG = {
   browser: true,
   dedupe: ['svelte']
};

export default () =>
{
   /** @type {import('vite').UserConfig} */
   return {
      root: 'src/',                 // Source location / esbuild root.
      base: `/${s_PACKAGE_ID}/`,    // Base module path that 30001 / served dev directory.
      publicDir: false,             // No public resources to copy.
      cacheDir: '../.vite-cache',   // Relative from root directory.

      resolve: { conditions: ['import', 'browser'] },

      esbuild: {
         target: ['es2022']
      },

      css: {
         // Creates a standard configuration for PostCSS with autoprefixer & postcss-preset-env.
         postcss: postcssConfig({ compress: s_COMPRESS, sourceMap: s_SOURCEMAPS })
      },

      // About server options:
      // - Set to `open` to boolean `false` to not open a browser window automatically. This is useful if you set up a
      // debugger instance in your IDE and launch it with the URL: 'http://localhost:30001/game'.
      //
      // - The top proxy entry redirects requests under the module path for `style.css` and following standard static
      // directories: `assets`, `lang`, and `packs` and will pull those resources from the main Foundry / 30000 server.
      // This is necessary to reference the dev resources as the root is `/src` and there is no public / static
      // resources served with this particular Vite configuration. Modify the proxy rule as necessary for your
      // static resources / project.
      server: {
         port: 30001,
         open: '/game',
         proxy: {
            // Serves static files from main Foundry server.
            [`^(/${s_PACKAGE_ID}/(assets|lang|packs|style.css))`]: 'http://localhost:30000',

            // All other paths besides package ID path are served from main Foundry server.
            [`^(?!/${s_PACKAGE_ID}/)`]: 'http://localhost:30000',

            // Enable socket.io from main Foundry server.
            '/socket.io': { target: 'ws://localhost:30000', ws: true }
         }
      },

      build: {
         outDir: __dirname,
         emptyOutDir: false,
         sourcemap: s_SOURCEMAPS,
         brotliSize: true,
         minify: s_COMPRESS ? 'terser' : false,
         target: ['es2022'],
         terserOptions: s_COMPRESS ? { ...terserConfig(), ecma: 2022 } : void 0,
         lib: {
            entry: './index.js',
            formats: ['es'],
            fileName: 'index'
         }
      },

      plugins: [
         svelte({
            compilerOptions: {
               // Provides a custom hash adding the string defined in `s_SVELTE_HASH_ID` to scoped Svelte styles;
               // This is reasonable to do as the framework styles in TRL compiled across `n` different packages will
               // be the same. Slightly modifying the hash ensures that your package has uniquely scoped styles for all
               // TRL components and makes it easier to review styles in the browser debugger.
               cssHash: ({ hash, css }) => `svelte-${s_SVELTE_HASH_ID}-${hash(css)}`
            },
            preprocess: preprocess()
         }),

         resolve(s_RESOLVE_CONFIG)  // Necessary when bundling npm-linked packages.
      ]
   };
};