rollup.config.js

import typescript from '@rollup/plugin-typescript';
import commonjs from '@rollup/plugin-commonjs';
import resolve from '@rollup/plugin-node-resolve';
import external from 'rollup-plugin-peer-deps-external';
import postcss from 'rollup-plugin-postcss';

const external_deps = ['react', 'react-dom'];

// CommonJS build configuration
const cjs_config = {
  input: 'src/index.ts',
  output: {
    file: 'dist/index.js',
    format: 'cjs',
    sourcemap: true,
    exports: 'named',
    globals: {
      react: 'React',
      'react-dom': 'ReactDOM'
    }
  },
  external: external_deps,
  plugins: [
    external(),
    postcss({
      modules: true,
      extract: 'styles.module.css'
    }),
    resolve({
      extensions: ['.js', '.jsx', '.ts', '.tsx']
    }),
    commonjs({
      transformMixedEsModules: true,
      include: [/node_modules/, /src/],
      requireReturnsDefault: 'auto'
    }),
    typescript({
      tsconfig: './tsconfig.json',
      exclude: ['example/**/*']
    })
  ]
};

// ES Module build configuration
const esm_config = {
  input: 'src/index.ts',
  output: {
    file: 'dist/index.esm.js',
    format: 'esm',
    sourcemap: true,
    exports: 'named'
  },
  external: external_deps,
  plugins: [
    external(),
    postcss({
      modules: true,
      extract: false
    }),
    resolve({
      extensions: ['.js', '.jsx', '.ts', '.tsx'],
      mainFields: ['module', 'jsnext:main', 'main'],
      browser: true,
      preferBuiltins: false
    }),
    commonjs({
      transformMixedEsModules: true,
      include: [/node_modules/],
      requireReturnsDefault: 'namespace',
      esmExternals: true
    }),
    typescript({
      tsconfig: './tsconfig.json',
      exclude: ['example/**/*']
    })
  ]
};

// Update ESM typescript config to ensure pure ES modules
esm_config.plugins = esm_config.plugins.map(plugin => {
  if (plugin?.name === 'typescript') {
    return typescript({
      tsconfig: './tsconfig.json',
      exclude: ['example/**/*'],
      module: 'esnext',
      target: 'es2015'
    });
  }
  return plugin;
});

export default [cjs_config, esm_config];