vite.shared.ts

import { readFileSync } from 'node:fs';
import path from 'node:path';

import type { UserConfig } from 'vite';

export interface SharedViteOptions {
  entry?: string | Record<string, string>;
  esbuild?: { jsx: string; jsxImportSource: string };
  vanillaExtract?: boolean;
}

const BASE_EXTERNALS = ['react', 'react-dom', 'react/jsx-runtime'];

export async function createViteConfig(options: SharedViteOptions = {}): Promise<UserConfig> {
  const { entry = 'src/index.ts', vanillaExtract = true, esbuild } = options;

  const dts = (await import('vite-plugin-dts')).default;
  const plugins: UserConfig['plugins'] = [];

  if (vanillaExtract) {
    const { vanillaExtractPlugin } = await import('@vanilla-extract/vite-plugin');
    plugins.push(vanillaExtractPlugin());
  }

  plugins.push(dts({ entryRoot: 'src', outDir: 'dist', tsconfigPath: './tsconfig.json' }));

  const cwd = process.cwd();
  const isMap = typeof entry !== 'string';
  const libEntry = isMap
    ? Object.fromEntries(Object.entries(entry).map(([k, v]) => [k, path.resolve(cwd, v)]))
    : path.resolve(cwd, entry);

  const fileName = isMap ? (_: string, name: string) => `${name}.mjs` : () => 'index.mjs';

  const pkg = JSON.parse(readFileSync(path.resolve(cwd, 'package.json'), 'utf8'));
  const depNames = new Set([
    ...BASE_EXTERNALS,
    ...Object.keys(pkg.dependencies || {}),
    ...Object.keys(pkg.peerDependencies || {}),
  ]);

  const rollupExternal = (id: string) => {
    if (id[0] === '.' || id[0] === '/' || id[0] === '\0') return false;
    if (depNames.has(id)) return true;
    const slashIdx = id.indexOf('/');
    if (slashIdx > 0) {
      const pkgName =
        id[0] === '@' ? id.slice(0, id.indexOf('/', slashIdx + 1)) : id.slice(0, slashIdx);
      return pkgName ? depNames.has(pkgName) : false;
    }
    return false;
  };

  return {
    plugins,
    ...(esbuild && { esbuild }),
    build: {
      lib: { entry: libEntry, formats: ['es'], fileName },
      rollupOptions: {
        external: rollupExternal,
        output: { preserveModules: false },
      },
      cssCodeSplit: false,
      minify: false,
      cssMinify: true,
      target: 'es2020',
    },
  };
}