rollup.config.mjs

import typescript from 'rollup-plugin-typescript2'
import pkg from './package.json' assert { type: 'json' }
import terser from '@rollup/plugin-terser'
import resolve from '@rollup/plugin-node-resolve'

export default [
  {
    input: './src/index.ts',
    external: ['illusory'],
    plugins: [
      typescript({
        useTsconfigDeclarationDir: true,
        tsconfigOverride: {
          compilerOptions: {
            declarationDir: pkg.types
          }
        }
      })
    ],

    output: [
      {
        file: pkg.module,
        format: 'es'
      }
    ]
  },
  {
    input: './src/index.ts',
    external: ['illusory'],
    plugins: [
      typescript({
        tsconfigOverride: {
          compilerOptions: {
            target: 'es5',
            declaration: false
          }
        }
      })
    ],

    output: [
      {
        file: pkg.main,
        format: 'cjs'
      }
    ]
  },
  {
    input: './src/index.ts',
    external: ['illusory'],
    plugins: [
      typescript({
        tsconfigOverride: {
          compilerOptions: {
            target: 'es5',
            declaration: false
          }
        }
      }),
      terser({
        sourceMap: true,
        output: {
          comments: 'all'
        }
      }),
      resolve({
        mainFields: ['unpkg']
      })
    ],

    output: [
      {
        file: pkg.unpkg,
        format: 'iife',
        name: 'window',
        extend: true,
        globals: {
          illusory: 'window'
        }
      }
    ]
  }
]