rollup.config.ts

import aliasPlugin, { type Alias } from '@rollup/plugin-alias';
import commonjsPlugin from '@rollup/plugin-commonjs';
import jsonPlugin from '@rollup/plugin-json';
import { nodeResolve } from '@rollup/plugin-node-resolve';
import typescriptPlugin from '@rollup/plugin-typescript';
import fs from 'fs-extra';
import type { InputOptions, RollupOptions } from 'rollup';
import dtsPlugin from 'rollup-plugin-dts';

const outputPath = `dist`;

const commonPlugins = [
  commonjsPlugin(),
  jsonPlugin(),
  nodeResolve({ exportConditions: ['node'] }), // https://github.com/SBoudrias/Inquirer.js/issues/1153#issuecomment-1212827810
  typescriptPlugin(),
];

const commonAliases: Alias[] = [];

const commonInputOptions: InputOptions = {
  input: 'src/index.ts',
  plugins: [aliasPlugin({ entries: commonAliases }), commonPlugins],
};

const cliCommands = await fs.readdir('src/cli');

const config: RollupOptions[] = [
  // ESM output.
  {
    ...commonInputOptions,
    output: [
      {
        extend: true,
        file: `${outputPath}/index.mjs`,
        format: 'esm',
      },
    ],
  },

  // Type definitions output.
  {
    ...commonInputOptions,
    plugins: [commonInputOptions.plugins, dtsPlugin()],
    output: [
      {
        extend: true,
        file: `${outputPath}/index.d.ts`,
        format: 'esm',
      },
      {
        extend: true,
        file: `${outputPath}/index.d.mts`,
        format: 'esm',
      },
    ],
  },

  // CLI output.
  ...cliCommands.map<RollupOptions>((c) => ({
    ...commonInputOptions,
    input: `src/cli/${c}/index.ts`,
    output: [
      {
        extend: true,
        file: `${outputPath}/${c}.cli.mjs`,
        format: 'esm',
      },
    ],
  })),
];

export default config;