old_contents: const resolve = require('rollup-plugin-node-resolve');
  const commonjs = require('rollup-plugin-commonjs');
  const babel = require('rollup-plugin-babel');
  const uglify = require('rollup-plugin-uglify').uglify;
  
  const pkg = require('./package.json');
  const version = process.env.VERSION || pkg.version;
  const name = process.env.NAME || pkg.name;
  const author = process.env.AUTHOR || pkg.author;
  
  const banner = `/* 
   * @preserve
   * ${name}.js v${version}
   * ${new Date().getFullYear()} - powered by ${author}
   */
  `
  const config = module.exports = {
  
    input: 'src/main.js',
    output: {
      file: `dist/${name}.js`,
      format: 'umd',
      name: name,
      banner: banner
    },
    plugins: [
      resolve(),
      commonjs(),
      babel()
    ]
  
  }
  
  if (process.env.NODE_ENV === 'production') {
    config.plugins.push(uglify({
      output: {
        comments: function (node, comment) {
          var text = comment.value;
          var type = comment.type;
          if (type == "comment2") {
            return /@preserve|@license|@cc_on/i.test(text);
          }
        }
      }
    }));
  } else {
    config.output.file = `dist/${name}.dev.js`;
  }
new_contents: const resolve = require('rollup-plugin-node-resolve');
  const commonjs = require('rollup-plugin-commonjs');
  const babel = require('rollup-plugin-babel');
  const uglify = require('rollup-plugin-uglify').uglify;
  
  const pkg = require('./package.json');
  const version = process.env.VERSION || pkg.version;
  const name = process.env.NAME || pkg.name;
  const author = process.env.AUTHOR || pkg.author;
  
  const banner = `/* 
   * @preserve
   * ${name}.js v${version}
   * ${new Date().getFullYear()} - powered by ${author}
   */
  `
  
  const isProduction = process.env.NODE_ENV === 'production';
  
  module.exports = {
  
    input: 'src/main.js',
    output: {
      file: `dist/${name}${isProduction ? '.min.' : '.debug.'}js`,
      format: 'umd',
      name: name,
      banner: banner
    },
    plugins: [
      resolve(),
      commonjs(),
      babel(),
      isProduction && uglify({
        output: {
          comments: function (node, comment) {
            var text = comment.value;
            var type = comment.type;
            if (type == "comment2") {
              return /@preserve|@license|@cc_on/i.test(text);
            }
          }
        }
      })
    ]
  
  }
subject: modify rollup configuration