如何通过 Rollup.js 打包 JavaScript

learn-rollup/
├── src/
│   ├── scripts/
│   │   ├── modules/
│   │   │   ├── mod1.js
│   │   │   └── mod2.js
│   │   └── main.js
│   └── styles/
│       └── main.css
└── package.json

# Move to the folder where you keep your dev projects.
cd /path/to/your/projects

# Clone the starter branch of the app from GitHub.
git clone -b step-0 --single-branch https://github.com/jlengstorf/learn-rollup.git

# The files are downloaded to /path/to/your/projects/learn-rollup/

npm install --save-dev rollup

export default {
  entry: 'src/scripts/main.js',
  dest: 'build/js/main.min.js',
  format: 'iife',
  sourceMap: 'inline',
};

./node_modules/.bin/rollup -c

(function () {
'use strict';

/**
 * Says hello.
 * @param  {String} name a name
 * @return {String}      a greeting for name
 */
function sayHelloTo( name ) {
  const toSay = Hello, ${name}!;

  return toSay;
}

/**
 * Adds all the values in an array.
 * @param  {Array} arr an array of numbers
 * @return {Number}    the sum of all the array values
 */
const addArray = arr => {
  const result = arr.reduce((a, b) => a + b, 0);

  return result;
};

// Import a couple modules for testing.
// Run some functions from our imported modules.
const result1 = sayHelloTo('Jason');
const result2 = addArray([1, 2, 3, 4]);

// Print the results on the page.
const printTarget = document.getElementsByClassName('debug__output')[0];

printTarget.innerText = sayHelloTo('Jason') => ${result1}\n\n
printTarget.innerText += addArray([1, 2, 3, 4]) => ${result2};

}());
//# sourceMappingURL=data:application/json;charset=utf-8;base64,...

# Install Rollup’s Babel plugin.
npm install --save-dev rollup-plugin-babel

# Install the Babel preset for transpiling ES2015 using Rollup.
npm install --save-dev babel-preset-es2015-rollup

{
  "presets": ["es2015-rollup"],
}

// Rollup plugins
import babel from 'rollup-plugin-babel';

export default {
  entry: 'src/scripts/main.js',
  dest: 'build/js/main.min.js',
  format: 'iife',
  sourceMap: 'inline',
  plugins: [
    babel({
      exclude: 'node_modules/**',
    }),
  ],
};

./node_modules/.bin/rollup -c

// 译者注：若执行报错，运行 npm install --save-dev babel-preset-es2015 具体issue 详情见：https://github.com/jlengstorf/learn-rollup/issues/2

var addArray = function addArray(arr) {
  var result = arr.reduce(function (a, b) {
    return a + b;
  }, 0);

  return result;
};

npm install --save-dev rollup-plugin-eslint

$ ./node_modules/.bin/eslint --init
? How would you like to configure ESLint? Answer questions about your style
? Are you using ECMAScript 6 features? Yes
? Are you using ES6 modules? Yes
? Where will your code run? Browser
? Do you use CommonJS? No
? Do you use JSX? No
? What style of indentation do you use? Spaces
? What quotes do you use for strings? Single
? What line endings do you use? Unix
? Do you require semicolons? Yes
? What format do you want your config file to be in? JSON
Successfully created .eslintrc.json file in /Users/jlengstorf/dev/code.lengstorf.com/projects/learn-rollup

{
  "env": {
    "browser": true,
    "es6": true
  },
  "extends": "eslint:recommended",
  "parserOptions": {
    "sourceType": "module"
  },
  "rules": {
    "indent": [
      "error",
      4
    ],
    "linebreak-style": [
      "error",
      "unix"
    ],
    "quotes": [
      "error",
      "single"
    ],
    "semi": [
      "error",
      "always"
    ]
  }
}

{
  "env": {
    "browser": true,
    "es6": true
  },
  "globals": {
    "ENV": true
  },
  "extends": "eslint:recommended",
  "parserOptions": {
    "sourceType": "module"
  },
  "rules": {
    "indent": [
      "error",
      2
    ],
    "linebreak-style": [
      "error",
      "unix"
    ],
    "quotes": [
      "error",
      "single"
    ],
    "semi": [
      "error",
      "always"
    ]
  }
}

// Rollup plugins
import babel from 'rollup-plugin-babel';
import eslint from 'rollup-plugin-eslint';

export default {
  entry: 'src/scripts/main.js',
  dest: 'build/js/main.min.js',
  format: 'iife',
  sourceMap: 'inline',
  plugins: [
    babel({
      exclude: 'node_modules/**',
    }),
    eslint({
      exclude: [
        'src/styles/**',
      ]
    }),
  ],
};

$ ./node_modules/.bin/rollup -c

/Users/jlengstorf/dev/code.lengstorf.com/projects/learn-rollup/src/scripts/main.js
  12:64  error  Missing semicolon  semi

✖ 1 problem (1 error, 0 warnings)

npm install --save debug

// Import a couple modules for testing.
import { sayHelloTo } from './modules/mod1';
import addArray from './modules/mod2';

// Import a logger for easier debugging.
import debug from 'debug';
const log = debug('app:log');

// Enable the logger.
debug.enable('*');
log('Logging is enabled!');

// Run some functions from our imported modules.
const result1 = sayHelloTo('Jason');
const result2 = addArray([1, 2, 3, 4]);

// Print the results on the page.
const printTarget = document.getElementsByClassName('debug__output')[0];

printTarget.innerText = sayHelloTo('Jason') => ${result1}\n\n;
printTarget.innerText += addArray([1, 2, 3, 4]) => ${result2};

$ ./node_modules/.bin/rollup -c
Treating 'debug' as external dependency
No name was provided for external module 'debug' in options.globals – guessing 'debug'

npm install --save-dev rollup-plugin-node-resolve rollup-plugin-commonjs

// Rollup plugins
import babel from 'rollup-plugin-babel';
import eslint from 'rollup-plugin-eslint';
import resolve from 'rollup-plugin-node-resolve';
import commonjs from 'rollup-plugin-commonjs';

export default {
  entry: 'src/scripts/main.js',
  dest: 'build/js/main.min.js',
  format: 'iife',
  sourceMap: 'inline',
  plugins: [
    resolve({
      jsnext: true,
      main: true,
      browser: true,
    }),
    commonjs(),
    eslint({
      exclude: [
        'src/styles/**',
      ]
    }),
    babel({
      exclude: 'node_modules/**',
    }),
  ],
};

// Import a logger for easier debugging.
import debug from 'debug';
const log = debug('app:log');

// The logger should only be disabled if we’re not in production.
if (ENV !== 'production') {

  // Enable the logger.
  debug.enable('*');
  log('Logging is enabled!');
} else {
  debug.disable();
}

npm install --save-dev rollup-plugin-replace

// Rollup plugins
import babel from 'rollup-plugin-babel';
import eslint from 'rollup-plugin-eslint';
import resolve from 'rollup-plugin-node-resolve';
import commonjs from 'rollup-plugin-commonjs';
import replace from 'rollup-plugin-replace';

export default {
  entry: 'src/scripts/main.js',
  dest: 'build/js/main.min.js',
  format: 'iife',
  sourceMap: 'inline',
  plugins: [
    resolve({
      jsnext: true,
      main: true,
      browser: true,
    }),
    commonjs(),
    eslint({
      exclude: [
        'src/styles/**',
      ]
    }),
    babel({
      exclude: 'node_modules/**',
    }),
    replace({
      ENV: JSON.stringify(process.env.NODE_ENV || 'development'),
    }),
  ],
};

NODE_ENV=production ./node_modules/.bin/rollup -c

npm install --save-dev rollup-plugin-uglify

// Rollup plugins
import babel from 'rollup-plugin-babel';
import eslint from 'rollup-plugin-eslint';
import resolve from 'rollup-plugin-node-resolve';
import commonjs from 'rollup-plugin-commonjs';
import replace from 'rollup-plugin-replace';
import uglify from 'rollup-plugin-uglify';

export default {
  entry: 'src/scripts/main.js',
  dest: 'build/js/main.min.js',
  format: 'iife',
  sourceMap: 'inline',
  plugins: [
    resolve({
      jsnext: true,
      main: true,
      browser: true,
    }),
    commonjs(),
    eslint({
      exclude: [
        'src/styles/**',
      ]
    }),
    babel({
      exclude: 'node_modules/**',
    }),
    replace({
      ENV: JSON.stringify(process.env.NODE_ENV || 'development'),
    }),
    (process.env.NODE_ENV === 'production' && uglify()),
  ],
};

NODE_ENV=production ./node_modules/.bin/rollup -c