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Browserifyに対するDuoの優位性について

11/18 21:19 追記

コメントにid:efclさんが書いてくれてますが、すいません、この記事、肝心なところ間違ってます…。

fmtというライブラリですが、npmにあるものとcomponentsにあるものでは名前は一緒ですが、内容が違っていました…。

本当はyields/fmt · GitHub見ないといけなかったのに、npmの方の chilts/fmt · GitHubをビルドしてしまってました。

実際にGitHubリポジトリ作っていただいているんで、そちら見ると分かりますが、Browserifyでビルドした方が(前半部分が圧縮されてることもあり)むしろファイルサイズ小さいです…。

Browserify 1.5Kb

(function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
var uid = require('uid');
var fmt = require('./fmt');

var msg = fmt('Your unique ID is %s!', uid());

var display = document.querySelector('.display');
var text = document.createTextNode(msg);

display.appendChild(text);

},{"./fmt":2,"uid":3}],2:[function(require,module,exports){

/**
 * toString.
 */

var toString = window.JSON
  ? JSON.stringify
  : String;

/**
 * Export `fmt`
 */

module.exports = fmt;

/**
 * Formatters
 */

fmt.o = toString;
fmt.s = String;
fmt.d = parseInt;

/**
 * Format the given `str`.
 *
 * @param {String} str
 * @param {...} args
 * @return {String}
 * @api public
 */

function fmt(str){
  var args = [].slice.call(arguments, 1);
  var j = 0;

  return str.replace(/%([a-z])/gi, function(_, f){
    return fmt[f]
      ? fmt[f](args[j++])
      : _ + f;
  });
}

},{}],3:[function(require,module,exports){
/**
 * Export `uid`
 */

module.exports = uid;

/**
 * Create a `uid`
 *
 * @param {String} len
 * @return {String} uid
 */

function uid(len) {
  len = len || 7;
  return Math.random().toString(35).substr(2, len);
}

},{}]},{},[1]);

Duo 2.5Kb

(function outer(modules, cache, entries){

  /**
   * Global
   */

  var global = (function(){ return this; })();

  /**
   * Require `name`.
   *
   * @param {String} name
   * @param {Boolean} jumped
   * @api public
   */

  function require(name, jumped){
    if (cache[name]) return cache[name].exports;
    if (modules[name]) return call(name, require);
    throw new Error('cannot find module "' + name + '"');
  }

  /**
   * Call module `id` and cache it.
   *
   * @param {Number} id
   * @param {Function} require
   * @return {Function}
   * @api private
   */

  function call(id, require){
    var m = cache[id] = { exports: {} };
    var mod = modules[id];
    var name = mod[2];
    var fn = mod[0];

    fn.call(m.exports, function(req){
      var dep = modules[id][1][req];
      return require(dep ? dep : req);
    }, m, m.exports, outer, modules, cache, entries);

    // expose as `name`.
    if (name) cache[name] = cache[id];

    return cache[id].exports;
  }

  /**
   * Require all entries exposing them on global if needed.
   */

  for (var id in entries) {
    if (entries[id]) {
      global[entries[id]] = require(id);
    } else {
      require(id);
    }
  }

  /**
   * Duo flag.
   */

  require.duo = true;

  /**
   * Expose cache.
   */

  require.cache = cache;

  /**
   * Expose modules
   */

  require.modules = modules;

  /**
   * Return newest require.
   */

   return require;
})({
1: [function(require, module, exports) {
var uid = require('matthewmueller/uid');
var fmt = require('yields/fmt');

var msg = fmt('Your unique ID is %s!', uid());

var display = document.querySelector('.display');
var text = document.createTextNode(msg);

display.appendChild(text);
}, {"matthewmueller/uid":2,"yields/fmt":3}],
2: [function(require, module, exports) {
/**
 * Export `uid`
 */

module.exports = uid;

/**
 * Create a `uid`
 *
 * @param {String} len
 * @return {String} uid
 */

function uid(len) {
  len = len || 7;
  return Math.random().toString(35).substr(2, len);
}

}, {}],
3: [function(require, module, exports) {

/**
 * toString.
 */

var toString = window.JSON
  ? JSON.stringify
  : function(_){ return String(_); };

/**
 * Export `fmt`
 */

module.exports = fmt;

/**
 * Formatters
 */

fmt.o = toString;
fmt.s = String;
fmt.d = parseInt;

/**
 * Format the given `str`.
 *
 * @param {String} str
 * @param {...} args
 * @return {String}
 * @api public
 */

function fmt(str){
  var args = [].slice.call(arguments, 1);
  var j = 0;

  return str.replace(/%([a-z])/gi, function(_, f){
    return fmt[f]
      ? fmt[f](args[j++])
      : _ + f;
  });
}

}, {}]}, {}, {"1":""})

結論

ということで、この例ではファイルサイズ比べるの間違いでした。すみません。

こうなると2つの違いは、フロントエンドの観点で言うと

  • package.jsonの有無
  • CSS@importの有無

くらいになり、確かな優位性っていうのはないなーという感じになります。エコシステムとしてはBrowserifyの方が優位くらいですね。

一応、最初に書いた記事は下記に残しておきますが、参考にはならないです。今度からもうちょっとちゃんと確認してからブログ上げることにします。

id:efcl さん、@hokacchaさんご指摘ありがとうございましたー!


11/18 21:19 追記 -> ここから最初に書いた記事になりますが、上記のとおり参考にはなりません…。

@ahomuさんのNode学園祭2014でのセッションでDuoについての感想があったのですが、こんな感じでした。

GitHubからのインストール&ビルドがシームレス◎
現状だとnpm + Browserifyと比べて優位性が低い

このスライドでも紹介していただいたんですが、会社の公式エンジニアブログでかんたんパッケージマネージャDuoという記事を書いていまして、優位性ってとこが気にかかったんで、ちょっと書いておこうかと。

Duoの優位性

Browserifyに対する優位性として、現状自分が考える優位性は2つあって、

  • package.json書かなくていい
  • ビルド後のファイルの容量が段違いに小さい

という2点です。それぞれ簡単に。

package.json書かなくていい

本当にフロントエンドな感じなのに、package.json書くのはちょっと…みたいなとこあると思います。別に無ければ全然良いんですが。

さっきのエンジニアブログで出したコード例で言うと最低でも

$ npm init
$ npm i -S uid fmt

しないと使えないですが、(npm initの時点で色々聞かれるし)Duoだとそれが全然いらないというのは良いです。

まあ、package.jsonを他のところからコピーしても良いんですが、やっぱりフロントエンドの作業でnode.jsの設定ファイル書くのはなー的なとこがあります。

ビルド後のファイルの容量が段違いに小さい

1つめはとって付けたかのような理由なんですが、こっちは結構切実かなあと思います。

Browserifyでビルドしたものより、DuoでビルドしたJSの方が格段にファイルサイズ小さいです。

これは考えてみたら当たり前のことなんですが、BrowserifyはNode.jsのAPIをブラウザで使えるという機能がウリになってるため、そのAPIのコードがビルド後に入ってきてしまいます。

対して、Duoの場合は単純にインストールしたライブラリと、自分が書いたコード、+αでDuoのコードが入るだけになっていますので、サイズが全然小さいです。

試しにエンジニアブログで書いてるuidfmt使ったコードをビルドしてみました。

Browserify 21.9kb

(function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
function display(selector, text) {
    var target = document.querySelector(selector),
        msg = document.createTextNode(text);

    target.appendChild(msg);
}

module.exports = display;

},{}],2:[function(require,module,exports){
// var uid = require('matthewmueller/uid');
// var fmt = require('yields/fmt');
var uid = require('uid');
var fmt = require('fmt');
var display = require('./display');

var msg = fmt('Your unique ID is %s!', uid());

display('.display', msg);

},{"./display":1,"fmt":3,"uid":4}],3:[function(require,module,exports){
// --------------------------------------------------------------------------------------------------------------------
//
// fmt.js - Command line output formatting.
//
// Copyright (c) 2012 Andrew Chilton - http://chilts.org/
// Written by Andrew Chilton <andychilton@gmail.com>
//
// License: http://opensource.org/licenses/MIT
//
// --------------------------------------------------------------------------------------------------------------------

var util = require('util');

// --------------------------------------------------------------------------------------------------------------------

var sep  = '===============================================================================';
var line = '-------------------------------------------------------------------------------';
var field = '                    ';

// --------------------------------------------------------------------------------------------------------------------

// separator
module.exports.separator = function() {
    console.log(sep);
};

// alias the above
module.exports.sep = module.exports.separator;

// line
module.exports.line = function() {
    console.log(line);
};

// title
module.exports.title = function(title) {
    var out = '--- ' + title + ' ';
    out += line.substr(out.length);
    console.log(out);
};

// field
module.exports.field = function(key, value) {
    console.log('' + key + field.substr(key.length) + ' : ' + value);
};

// subfield
module.exports.subfield = function(key, value) {
    console.log('- ' + key + field.substr(key.length + 2) + ' : ' + value);
};

// list item
module.exports.li = function(msg) {
    console.log('* ' + msg);
};

// dump
module.exports.dump = function(data, name) {
    if ( name ) {
        console.log(name + ' :', util.inspect(data, false, null, true));
    }
    else {
        console.log(util.inspect(data, false, null, true));
    }
};

// msg
module.exports.msg = function(msg) {
    console.log(msg);
};

// --------------------------------------------------------------------------------------------------------------------

},{"util":8}],4:[function(require,module,exports){
/**
 * Export `uid`
 */

module.exports = uid;

/**
 * Create a `uid`
 *
 * @param {String} len
 * @return {String} uid
 */

function uid(len) {
  len = len || 7;
  return Math.random().toString(35).substr(2, len);
}

},{}],5:[function(require,module,exports){
if (typeof Object.create === 'function') {
  // implementation from standard node.js 'util' module
  module.exports = function inherits(ctor, superCtor) {
    ctor.super_ = superCtor
    ctor.prototype = Object.create(superCtor.prototype, {
      constructor: {
        value: ctor,
        enumerable: false,
        writable: true,
        configurable: true
      }
    });
  };
} else {
  // old school shim for old browsers
  module.exports = function inherits(ctor, superCtor) {
    ctor.super_ = superCtor
    var TempCtor = function () {}
    TempCtor.prototype = superCtor.prototype
    ctor.prototype = new TempCtor()
    ctor.prototype.constructor = ctor
  }
}

},{}],6:[function(require,module,exports){
// shim for using process in browser

var process = module.exports = {};

process.nextTick = (function () {
    var canSetImmediate = typeof window !== 'undefined'
    && window.setImmediate;
    var canMutationObserver = typeof window !== 'undefined'
    && window.MutationObserver;
    var canPost = typeof window !== 'undefined'
    && window.postMessage && window.addEventListener
    ;

    if (canSetImmediate) {
        return function (f) { return window.setImmediate(f) };
    }

    var queue = [];

    if (canMutationObserver) {
        var hiddenDiv = document.createElement("div");
        var observer = new MutationObserver(function () {
            var queueList = queue.slice();
            queue.length = 0;
            queueList.forEach(function (fn) {
                fn();
            });
        });

        observer.observe(hiddenDiv, { attributes: true });

        return function nextTick(fn) {
            if (!queue.length) {
                hiddenDiv.setAttribute('yes', 'no');
            }
            queue.push(fn);
        };
    }

    if (canPost) {
        window.addEventListener('message', function (ev) {
            var source = ev.source;
            if ((source === window || source === null) && ev.data === 'process-tick') {
                ev.stopPropagation();
                if (queue.length > 0) {
                    var fn = queue.shift();
                    fn();
                }
            }
        }, true);

        return function nextTick(fn) {
            queue.push(fn);
            window.postMessage('process-tick', '*');
        };
    }

    return function nextTick(fn) {
        setTimeout(fn, 0);
    };
})();

process.title = 'browser';
process.browser = true;
process.env = {};
process.argv = [];

function noop() {}

process.on = noop;
process.addListener = noop;
process.once = noop;
process.off = noop;
process.removeListener = noop;
process.removeAllListeners = noop;
process.emit = noop;

process.binding = function (name) {
    throw new Error('process.binding is not supported');
};

// TODO(shtylman)
process.cwd = function () { return '/' };
process.chdir = function (dir) {
    throw new Error('process.chdir is not supported');
};

},{}],7:[function(require,module,exports){
module.exports = function isBuffer(arg) {
  return arg && typeof arg === 'object'
    && typeof arg.copy === 'function'
    && typeof arg.fill === 'function'
    && typeof arg.readUInt8 === 'function';
}
},{}],8:[function(require,module,exports){
(function (process,global){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

var formatRegExp = /%[sdj%]/g;
exports.format = function(f) {
  if (!isString(f)) {
    var objects = [];
    for (var i = 0; i < arguments.length; i++) {
      objects.push(inspect(arguments[i]));
    }
    return objects.join(' ');
  }

  var i = 1;
  var args = arguments;
  var len = args.length;
  var str = String(f).replace(formatRegExp, function(x) {
    if (x === '%%') return '%';
    if (i >= len) return x;
    switch (x) {
      case '%s': return String(args[i++]);
      case '%d': return Number(args[i++]);
      case '%j':
        try {
          return JSON.stringify(args[i++]);
        } catch (_) {
          return '[Circular]';
        }
      default:
        return x;
    }
  });
  for (var x = args[i]; i < len; x = args[++i]) {
    if (isNull(x) || !isObject(x)) {
      str += ' ' + x;
    } else {
      str += ' ' + inspect(x);
    }
  }
  return str;
};


// Mark that a method should not be used.
// Returns a modified function which warns once by default.
// If --no-deprecation is set, then it is a no-op.
exports.deprecate = function(fn, msg) {
  // Allow for deprecating things in the process of starting up.
  if (isUndefined(global.process)) {
    return function() {
      return exports.deprecate(fn, msg).apply(this, arguments);
    };
  }

  if (process.noDeprecation === true) {
    return fn;
  }

  var warned = false;
  function deprecated() {
    if (!warned) {
      if (process.throwDeprecation) {
        throw new Error(msg);
      } else if (process.traceDeprecation) {
        console.trace(msg);
      } else {
        console.error(msg);
      }
      warned = true;
    }
    return fn.apply(this, arguments);
  }

  return deprecated;
};


var debugs = {};
var debugEnviron;
exports.debuglog = function(set) {
  if (isUndefined(debugEnviron))
    debugEnviron = process.env.NODE_DEBUG || '';
  set = set.toUpperCase();
  if (!debugs[set]) {
    if (new RegExp('\\b' + set + '\\b', 'i').test(debugEnviron)) {
      var pid = process.pid;
      debugs[set] = function() {
        var msg = exports.format.apply(exports, arguments);
        console.error('%s %d: %s', set, pid, msg);
      };
    } else {
      debugs[set] = function() {};
    }
  }
  return debugs[set];
};


/**
 * Echos the value of a value. Trys to print the value out
 * in the best way possible given the different types.
 *
 * @param {Object} obj The object to print out.
 * @param {Object} opts Optional options object that alters the output.
 */
/* legacy: obj, showHidden, depth, colors*/
function inspect(obj, opts) {
  // default options
  var ctx = {
    seen: [],
    stylize: stylizeNoColor
  };
  // legacy...
  if (arguments.length >= 3) ctx.depth = arguments[2];
  if (arguments.length >= 4) ctx.colors = arguments[3];
  if (isBoolean(opts)) {
    // legacy...
    ctx.showHidden = opts;
  } else if (opts) {
    // got an "options" object
    exports._extend(ctx, opts);
  }
  // set default options
  if (isUndefined(ctx.showHidden)) ctx.showHidden = false;
  if (isUndefined(ctx.depth)) ctx.depth = 2;
  if (isUndefined(ctx.colors)) ctx.colors = false;
  if (isUndefined(ctx.customInspect)) ctx.customInspect = true;
  if (ctx.colors) ctx.stylize = stylizeWithColor;
  return formatValue(ctx, obj, ctx.depth);
}
exports.inspect = inspect;


// http://en.wikipedia.org/wiki/ANSI_escape_code#graphics
inspect.colors = {
  'bold' : [1, 22],
  'italic' : [3, 23],
  'underline' : [4, 24],
  'inverse' : [7, 27],
  'white' : [37, 39],
  'grey' : [90, 39],
  'black' : [30, 39],
  'blue' : [34, 39],
  'cyan' : [36, 39],
  'green' : [32, 39],
  'magenta' : [35, 39],
  'red' : [31, 39],
  'yellow' : [33, 39]
};

// Don't use 'blue' not visible on cmd.exe
inspect.styles = {
  'special': 'cyan',
  'number': 'yellow',
  'boolean': 'yellow',
  'undefined': 'grey',
  'null': 'bold',
  'string': 'green',
  'date': 'magenta',
  // "name": intentionally not styling
  'regexp': 'red'
};


function stylizeWithColor(str, styleType) {
  var style = inspect.styles[styleType];

  if (style) {
    return '\u001b[' + inspect.colors[style][0] + 'm' + str +
           '\u001b[' + inspect.colors[style][1] + 'm';
  } else {
    return str;
  }
}


function stylizeNoColor(str, styleType) {
  return str;
}


function arrayToHash(array) {
  var hash = {};

  array.forEach(function(val, idx) {
    hash[val] = true;
  });

  return hash;
}


function formatValue(ctx, value, recurseTimes) {
  // Provide a hook for user-specified inspect functions.
  // Check that value is an object with an inspect function on it
  if (ctx.customInspect &&
      value &&
      isFunction(value.inspect) &&
      // Filter out the util module, it's inspect function is special
      value.inspect !== exports.inspect &&
      // Also filter out any prototype objects using the circular check.
      !(value.constructor && value.constructor.prototype === value)) {
    var ret = value.inspect(recurseTimes, ctx);
    if (!isString(ret)) {
      ret = formatValue(ctx, ret, recurseTimes);
    }
    return ret;
  }

  // Primitive types cannot have properties
  var primitive = formatPrimitive(ctx, value);
  if (primitive) {
    return primitive;
  }

  // Look up the keys of the object.
  var keys = Object.keys(value);
  var visibleKeys = arrayToHash(keys);

  if (ctx.showHidden) {
    keys = Object.getOwnPropertyNames(value);
  }

  // IE doesn't make error fields non-enumerable
  // http://msdn.microsoft.com/en-us/library/ie/dww52sbt(v=vs.94).aspx
  if (isError(value)
      && (keys.indexOf('message') >= 0 || keys.indexOf('description') >= 0)) {
    return formatError(value);
  }

  // Some type of object without properties can be shortcutted.
  if (keys.length === 0) {
    if (isFunction(value)) {
      var name = value.name ? ': ' + value.name : '';
      return ctx.stylize('[Function' + name + ']', 'special');
    }
    if (isRegExp(value)) {
      return ctx.stylize(RegExp.prototype.toString.call(value), 'regexp');
    }
    if (isDate(value)) {
      return ctx.stylize(Date.prototype.toString.call(value), 'date');
    }
    if (isError(value)) {
      return formatError(value);
    }
  }

  var base = '', array = false, braces = ['{', '}'];

  // Make Array say that they are Array
  if (isArray(value)) {
    array = true;
    braces = ['[', ']'];
  }

  // Make functions say that they are functions
  if (isFunction(value)) {
    var n = value.name ? ': ' + value.name : '';
    base = ' [Function' + n + ']';
  }

  // Make RegExps say that they are RegExps
  if (isRegExp(value)) {
    base = ' ' + RegExp.prototype.toString.call(value);
  }

  // Make dates with properties first say the date
  if (isDate(value)) {
    base = ' ' + Date.prototype.toUTCString.call(value);
  }

  // Make error with message first say the error
  if (isError(value)) {
    base = ' ' + formatError(value);
  }

  if (keys.length === 0 && (!array || value.length == 0)) {
    return braces[0] + base + braces[1];
  }

  if (recurseTimes < 0) {
    if (isRegExp(value)) {
      return ctx.stylize(RegExp.prototype.toString.call(value), 'regexp');
    } else {
      return ctx.stylize('[Object]', 'special');
    }
  }

  ctx.seen.push(value);

  var output;
  if (array) {
    output = formatArray(ctx, value, recurseTimes, visibleKeys, keys);
  } else {
    output = keys.map(function(key) {
      return formatProperty(ctx, value, recurseTimes, visibleKeys, key, array);
    });
  }

  ctx.seen.pop();

  return reduceToSingleString(output, base, braces);
}


function formatPrimitive(ctx, value) {
  if (isUndefined(value))
    return ctx.stylize('undefined', 'undefined');
  if (isString(value)) {
    var simple = '\'' + JSON.stringify(value).replace(/^"|"$/g, '')
                                             .replace(/'/g, "\\'")
                                             .replace(/\\"/g, '"') + '\'';
    return ctx.stylize(simple, 'string');
  }
  if (isNumber(value))
    return ctx.stylize('' + value, 'number');
  if (isBoolean(value))
    return ctx.stylize('' + value, 'boolean');
  // For some reason typeof null is "object", so special case here.
  if (isNull(value))
    return ctx.stylize('null', 'null');
}


function formatError(value) {
  return '[' + Error.prototype.toString.call(value) + ']';
}


function formatArray(ctx, value, recurseTimes, visibleKeys, keys) {
  var output = [];
  for (var i = 0, l = value.length; i < l; ++i) {
    if (hasOwnProperty(value, String(i))) {
      output.push(formatProperty(ctx, value, recurseTimes, visibleKeys,
          String(i), true));
    } else {
      output.push('');
    }
  }
  keys.forEach(function(key) {
    if (!key.match(/^\d+$/)) {
      output.push(formatProperty(ctx, value, recurseTimes, visibleKeys,
          key, true));
    }
  });
  return output;
}


function formatProperty(ctx, value, recurseTimes, visibleKeys, key, array) {
  var name, str, desc;
  desc = Object.getOwnPropertyDescriptor(value, key) || { value: value[key] };
  if (desc.get) {
    if (desc.set) {
      str = ctx.stylize('[Getter/Setter]', 'special');
    } else {
      str = ctx.stylize('[Getter]', 'special');
    }
  } else {
    if (desc.set) {
      str = ctx.stylize('[Setter]', 'special');
    }
  }
  if (!hasOwnProperty(visibleKeys, key)) {
    name = '[' + key + ']';
  }
  if (!str) {
    if (ctx.seen.indexOf(desc.value) < 0) {
      if (isNull(recurseTimes)) {
        str = formatValue(ctx, desc.value, null);
      } else {
        str = formatValue(ctx, desc.value, recurseTimes - 1);
      }
      if (str.indexOf('\n') > -1) {
        if (array) {
          str = str.split('\n').map(function(line) {
            return '  ' + line;
          }).join('\n').substr(2);
        } else {
          str = '\n' + str.split('\n').map(function(line) {
            return '   ' + line;
          }).join('\n');
        }
      }
    } else {
      str = ctx.stylize('[Circular]', 'special');
    }
  }
  if (isUndefined(name)) {
    if (array && key.match(/^\d+$/)) {
      return str;
    }
    name = JSON.stringify('' + key);
    if (name.match(/^"([a-zA-Z_][a-zA-Z_0-9]*)"$/)) {
      name = name.substr(1, name.length - 2);
      name = ctx.stylize(name, 'name');
    } else {
      name = name.replace(/'/g, "\\'")
                 .replace(/\\"/g, '"')
                 .replace(/(^"|"$)/g, "'");
      name = ctx.stylize(name, 'string');
    }
  }

  return name + ': ' + str;
}


function reduceToSingleString(output, base, braces) {
  var numLinesEst = 0;
  var length = output.reduce(function(prev, cur) {
    numLinesEst++;
    if (cur.indexOf('\n') >= 0) numLinesEst++;
    return prev + cur.replace(/\u001b\[\d\d?m/g, '').length + 1;
  }, 0);

  if (length > 60) {
    return braces[0] +
           (base === '' ? '' : base + '\n ') +
           ' ' +
           output.join(',\n  ') +
           ' ' +
           braces[1];
  }

  return braces[0] + base + ' ' + output.join(', ') + ' ' + braces[1];
}


// NOTE: These type checking functions intentionally don't use `instanceof`
// because it is fragile and can be easily faked with `Object.create()`.
function isArray(ar) {
  return Array.isArray(ar);
}
exports.isArray = isArray;

function isBoolean(arg) {
  return typeof arg === 'boolean';
}
exports.isBoolean = isBoolean;

function isNull(arg) {
  return arg === null;
}
exports.isNull = isNull;

function isNullOrUndefined(arg) {
  return arg == null;
}
exports.isNullOrUndefined = isNullOrUndefined;

function isNumber(arg) {
  return typeof arg === 'number';
}
exports.isNumber = isNumber;

function isString(arg) {
  return typeof arg === 'string';
}
exports.isString = isString;

function isSymbol(arg) {
  return typeof arg === 'symbol';
}
exports.isSymbol = isSymbol;

function isUndefined(arg) {
  return arg === void 0;
}
exports.isUndefined = isUndefined;

function isRegExp(re) {
  return isObject(re) && objectToString(re) === '[object RegExp]';
}
exports.isRegExp = isRegExp;

function isObject(arg) {
  return typeof arg === 'object' && arg !== null;
}
exports.isObject = isObject;

function isDate(d) {
  return isObject(d) && objectToString(d) === '[object Date]';
}
exports.isDate = isDate;

function isError(e) {
  return isObject(e) &&
      (objectToString(e) === '[object Error]' || e instanceof Error);
}
exports.isError = isError;

function isFunction(arg) {
  return typeof arg === 'function';
}
exports.isFunction = isFunction;

function isPrimitive(arg) {
  return arg === null ||
         typeof arg === 'boolean' ||
         typeof arg === 'number' ||
         typeof arg === 'string' ||
         typeof arg === 'symbol' ||  // ES6 symbol
         typeof arg === 'undefined';
}
exports.isPrimitive = isPrimitive;

exports.isBuffer = require('./support/isBuffer');

function objectToString(o) {
  return Object.prototype.toString.call(o);
}


function pad(n) {
  return n < 10 ? '0' + n.toString(10) : n.toString(10);
}


var months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep',
              'Oct', 'Nov', 'Dec'];

// 26 Feb 16:19:34
function timestamp() {
  var d = new Date();
  var time = [pad(d.getHours()),
              pad(d.getMinutes()),
              pad(d.getSeconds())].join(':');
  return [d.getDate(), months[d.getMonth()], time].join(' ');
}


// log is just a thin wrapper to console.log that prepends a timestamp
exports.log = function() {
  console.log('%s - %s', timestamp(), exports.format.apply(exports, arguments));
};


/**
 * Inherit the prototype methods from one constructor into another.
 *
 * The Function.prototype.inherits from lang.js rewritten as a standalone
 * function (not on Function.prototype). NOTE: If this file is to be loaded
 * during bootstrapping this function needs to be rewritten using some native
 * functions as prototype setup using normal JavaScript does not work as
 * expected during bootstrapping (see mirror.js in r114903).
 *
 * @param {function} ctor Constructor function which needs to inherit the
 *     prototype.
 * @param {function} superCtor Constructor function to inherit prototype from.
 */
exports.inherits = require('inherits');

exports._extend = function(origin, add) {
  // Don't do anything if add isn't an object
  if (!add || !isObject(add)) return origin;

  var keys = Object.keys(add);
  var i = keys.length;
  while (i--) {
    origin[keys[i]] = add[keys[i]];
  }
  return origin;
};

function hasOwnProperty(obj, prop) {
  return Object.prototype.hasOwnProperty.call(obj, prop);
}

}).call(this,require('_process'),typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{"./support/isBuffer":7,"_process":6,"inherits":5}]},{},[2]);

Duo 2.7kb

(function outer(modules, cache, entries){

  /**
   * Global
   */

  var global = (function(){ return this; })();

  /**
   * Require `name`.
   *
   * @param {String} name
   * @param {Boolean} jumped
   * @api public
   */

  function require(name, jumped){
    if (cache[name]) return cache[name].exports;
    if (modules[name]) return call(name, require);
    throw new Error('cannot find module "' + name + '"');
  }

  /**
   * Call module `id` and cache it.
   *
   * @param {Number} id
   * @param {Function} require
   * @return {Function}
   * @api private
   */

  function call(id, require){
    var m = cache[id] = { exports: {} };
    var mod = modules[id];
    var name = mod[2];
    var fn = mod[0];

    fn.call(m.exports, function(req){
      var dep = modules[id][1][req];
      return require(dep ? dep : req);
    }, m, m.exports, outer, modules, cache, entries);

    // expose as `name`.
    if (name) cache[name] = cache[id];

    return cache[id].exports;
  }

  /**
   * Require all entries exposing them on global if needed.
   */

  for (var id in entries) {
    if (entries[id]) {
      global[entries[id]] = require(id);
    } else {
      require(id);
    }
  }

  /**
   * Duo flag.
   */

  require.duo = true;

  /**
   * Expose cache.
   */

  require.cache = cache;

  /**
   * Expose modules
   */

  require.modules = modules;

  /**
   * Return newest require.
   */

   return require;
})({
1: [function(require, module, exports) {
var uid = require('matthewmueller/uid');
var fmt = require('yields/fmt');
var display = require('./display');

var msg = fmt('Your unique ID is %s!', uid());

display('.display', msg);

}, {"matthewmueller/uid":2,"yields/fmt":3,"./display":4}],
2: [function(require, module, exports) {
/**
 * Export `uid`
 */

module.exports = uid;

/**
 * Create a `uid`
 *
 * @param {String} len
 * @return {String} uid
 */

function uid(len) {
  len = len || 7;
  return Math.random().toString(35).substr(2, len);
}

}, {}],
3: [function(require, module, exports) {

/**
 * toString.
 */

var toString = window.JSON
  ? JSON.stringify
  : function(_){ return String(_); };

/**
 * Export `fmt`
 */

module.exports = fmt;

/**
 * Formatters
 */

fmt.o = toString;
fmt.s = String;
fmt.d = parseInt;

/**
 * Format the given `str`.
 *
 * @param {String} str
 * @param {...} args
 * @return {String}
 * @api public
 */

function fmt(str){
  var args = [].slice.call(arguments, 1);
  var j = 0;

  return str.replace(/%([a-z])/gi, function(_, f){
    return fmt[f]
      ? fmt[f](args[j++])
      : _ + f;
  });
}

}, {}],
4: [function(require, module, exports) {
function display(selector, text) {
    var target = document.querySelector(selector),
        msg = document.createTextNode(text);

    target.appendChild(msg);
}

module.exports = display;

}, {}]}, {}, {"1":""})

Conclusion

ということで、フロントエンドでCommonJSスタイルを使いたい!だけど、特にNode.jsのAPIは使わないわ…っていう場合にはDuoも有効な選択肢じゃないかなーと思います。

とは言え、自分もSubstack大好きっ子なんでBrowserifyも好きなんですけども。