rollup.config.ts

// rollup.config.ts
import typescript  from '@rollup/plugin-typescript'
import nodeResolve from '@rollup/plugin-node-resolve'
import commonjs    from '@rollup/plugin-commonjs'
import terser      from '@rollup/plugin-terser'

const libraryName = 'tapscript'

const treeshake = {
	moduleSideEffects: false,
	propertyReadSideEffects: false,
	tryCatchDeoptimization: false
}

const onwarn = warning => {
	// eslint-disable-next-line no-console
	console.error(
		'Building Rollup produced warnings that need to be resolved. ' +
			'Please keep in mind that the browser build may never have external dependencies!'
	);
	// eslint-disable-next-line unicorn/error-message
	throw Object.assign(new Error(), warning);
}

const tsConfig = { 
  compilerOptions: {
    declaration: false,
    declarationDir: null,
    declarationMap: false
  }
}

const nodeConfig = {
  input: 'src/index.ts',
  onwarn,
  output: [
    {
      file      : 'dist/main.cjs',
      format    : 'cjs',
      sourcemap : true,
    },
    {
      file      : 'dist/module.mjs',
      format    : 'es',
      sourcemap : true,
      minifyInternalExports: false
    },
  ],
  plugins: [ typescript(tsConfig), nodeResolve(), commonjs() ],
  strictDeprecations: true,
  treeshake
}

const browserConfig = {
  input: 'src/index.ts',
  onwarn,
  output: [
    {
      file      : 'dist/bundle.min.js',
      format    : 'iife',
      name      : libraryName,
      plugins   : [terser()],
      sourcemap : true
    },
  ],
  plugins: [ 
    typescript(tsConfig), 
    nodeResolve({ browser: true }), 
    commonjs() 
  ],
  strictDeprecations: true,
  treeshake
}

export default [ nodeConfig, browserConfig ]