rollup.config.mjs

import path from 'path';
import resolve from '@rollup/plugin-node-resolve';
import commonjs from '@rollup/plugin-commonjs';
import alias from '@rollup/plugin-alias';
import typescript from 'rollup-plugin-typescript2';
import dts from 'rollup-plugin-dts';
import del from 'rollup-plugin-delete';

const modules = [
  'Animatry',
  'use-animatry'
];
const barrel = 'index';
const allEntries = [...modules, barrel];

const kebabToCamel = str =>
  str.replace(/-([a-z])/g, (_, c) => c.toUpperCase());

const getInputPath = name =>
  path.join('src', name === barrel ? '' : name, 'index.ts');

const isExternal = id =>
  id === 'react' ||
  id === 'react-dom' ||
  id.startsWith('animatry') ||
  id.startsWith('animatry/core') ||
  allEntries.some(name => id === `@${name}` || id.startsWith(`@${name}/`));

const rewriteFlatImports = {
  name: 'rewrite-flat-imports',
  generateBundle(_opts, bundle) {
    const pattern = new RegExp(`@(${modules.join('|')})`, 'g');
    for (const file of Object.values(bundle)) {
      if (file.type !== 'chunk') continue;
      file.code = file.code
        .replace(pattern, (_, mod) => `./${kebabToCamel(mod)}.js`)
        .replace(/\.\/([a-z0-9-]+)\/\1\.js/g, './$1.js')
        .replace(/\.\/([a-z0-9-]+)\/index\.js/g, './$1.js');
    }
  }
};


const aliasEntries = modules.map(name => ({
  find: `@${name}`,
  replacement: path.resolve(`./src/${name}`),
}));

const noDecl = {
  tsconfigOverride: {
    compilerOptions: {
      declaration: false,
      declarationMap: false,
    }
  },
  clean: true
};

// ESM Build
const esmPlugins = [
  resolve(),
  alias({ entries: aliasEntries }),
  commonjs({ requireReturnsDefault: 'auto' }),
  typescript({
    tsconfig: './tsconfig.json',
    ...noDecl
  }),
  rewriteFlatImports
];

const createEsmConfig = name => ({
  input: getInputPath(name),
  output: {
    file: `dist/esm/${kebabToCamel(name)}.js`,
    format: 'esm',
  },
  external: isExternal,
  plugins: esmPlugins,
});

const esmConfigs = allEntries.map(createEsmConfig);

// Type declarations
const createDtsConfig = name => ({
  input: getInputPath(name),
  output: {
    file: `dist/types/${kebabToCamel(name)}.d.ts`,
    format: 'es',
  },
  plugins: [
    alias({ entries: aliasEntries }),
    dts(),
    name === barrel && del({
      targets: ['dist/esm/*/', 'dist/umd/*'],
      runOnce: true
    }),
    name === barrel && del({
      targets: ['dist/esm/index.d.ts', 'dist/umd/index.d.ts']
    })
  ].filter(Boolean)
});

const dtsConfigs = allEntries.map(createDtsConfig);

export default [
  ...esmConfigs,
  ...dtsConfigs
];