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,
    typhonjsRuntime }       from '@typhonjs-fvtt/runtime/rollup';

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

// EXPERIMENTAL: Set to true to enable linking against the TyphonJS Runtime Library module.
// You must add a Foundry module dependency on the `typhonjs` Foundry package or manually install it in Foundry from:
// https://github.com/typhonjs-fvtt-lib/typhonjs/releases/latest/download/module.json
const s_TYPHONJS_MODULE_LIB = false;

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

// ATTENTION!
// You must change `base` and the `proxy` strings replacing `/modules/bossbar/` with your
// module or system ID.

export default () =>
{
    /** @type {import('vite').UserConfig} */
    return {
        root: 'src/',                             // Source location / esbuild root.
        base: '/modules/bossbar/',   // 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', 'chrome100'],
            keepNames: true   // Note: doesn't seem to work.
        },
        
        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 for `lang` will pull the language 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.
        server: {
            port: 30001,
            open: '/game',
            proxy: {
                '^(/modules/bossbar/languages)': 'http://localhost:30000',
                '^(?!/modules/bossbar/)': 'http://localhost:30000',
                '/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', 'chrome100'],
            terserOptions: s_COMPRESS ? { ...terserConfig(), ecma: 2022 } : void 0,
            lib: {
                entry: './module.js',
                formats: ['es'],
                fileName: 'index'
            }
        },
        
        plugins: [
            svelte({
                preprocess: preprocess(),
                onwarn: (warning, handler) =>
                {
                    // Suppress `a11y-missing-attribute` for missing href in <a> links.
                    // Foundry doesn't follow accessibility rules.
                    if (warning.message.includes(`<a> element should have an href attribute`)) { return; }
                    
                    // Let Rollup handle all other warnings normally.
                    handler(warning);
                },
            }),
            
            resolve(s_RESOLVE_CONFIG),    // Necessary when bundling npm-linked packages.
            
            // When s_TYPHONJS_MODULE_LIB is true transpile against the Foundry module version of TRL.
            s_TYPHONJS_MODULE_LIB && typhonjsRuntime()
        ]
    };
};