old_contents: // Inspired by (but complete rewrite of) requirejs-metagen
  var _           = require('lodash/fp'),
      Promise     = require('bluebird'),
      readDir     = Promise.promisify(require('recursive-readdir')),
      fs          = Promise.promisifyAll(require('fs'));
  
  // Path Utils
  var filesRelative = (dir, ex) => readDir(dir, ex).map(x => x.slice(dir.length));
  var noExt = file => file.slice(0, _.lastIndexOf('.', file));
  
  // Core
  var metagen = dir => filesRelative(dir.path, dir.exclusions || [dir.output || 'all.js']).then(files =>
      fs.writeFileAsync(dir.path + (dir.output || 'all.js'), dir.format(files, dir))
  );
  
  // Formats
  metagen.formats = {};
  metagen.formats.commonJS = files => `define(function(require) {
      return {
          ${ files.map(file => `'${ noExt(file) }': require('./${ noExt(file) }')`).join(',\n        ') }
      };
  });`;
  metagen.formats.amd = files => `define([
      ${ files.map(file => `'${ noExt(file) }'`).join(',\n    ') }
  ], function() {
      return {
          ${ files.map((file, i) => `'${ noExt(file) }': arguments[${ i }]`).join(',\n        ') }
      }
  });`;
  
  // use FP when https://github.com/lodash/lodash/pull/2503 is released
  var zipObjectDeep = require('lodash/zipObjectDeep');
  
  // Deep Formats
  var deepKeys    = _.map(_.flow(noExt, _.replace('/', '.'))),
      stringify   = x => JSON.stringify(x, null, 4),
      indent      = _.replace(/\n/g, '\n    '),
      unquote     = _.replace(/"/g, ''),
      deepify     = _.flow(zipObjectDeep, stringify, indent, unquote);
      
  metagen.formats.deepCommonJS = files => `define(function(require) {
      return ${ deepify(deepKeys(files), files.map(file => `require('${ noExt(file) }')`))};
  });`;
  metagen.formats.deepAMD = files => `define([
      ${ files.map(file => `'${ noExt(file) }'`).join(',\n    ') }
  ], function() {
      return ${ deepify(deepKeys(files), files.map((file, i) => `arguments[${ i }]`))};
  });`;
  
  module.exports = metagen;
new_contents: // Inspired by (but complete rewrite of) requirejs-metagen
  var _           = require('lodash/fp'),
      Promise     = require('bluebird'),
      readDir     = Promise.promisify(require('recursive-readdir')),
      fs          = Promise.promisifyAll(require('fs'));
  
  // Path Utils
  var filesRelative = (dir, ex) => readDir(dir, ex).map(x => x.slice(dir.length));
  var noExt = file => file.slice(0, _.lastIndexOf('.', file));
  
  // Core
  var metagen = dir => filesRelative(dir.path, dir.exclusions || [dir.output || 'all.js']).then(files =>
      fs.writeFileAsync(dir.path + (dir.output || 'all.js'), dir.format(files, dir))
  );
  
  // Formats
  metagen.formats = {};
  metagen.formats.commonJS = files => `define(function(require) {
      return {
          ${ files.map(file => `'${ noExt(file) }': require('./${ noExt(file) }')`).join(',\n        ') }
      };
  });`;
  metagen.formats.amd = files => `define([
      ${ files.map(file => `'${ noExt(file) }'`).join(',\n    ') }
  ], function() {
      return {
          ${ files.map((file, i) => `'${ noExt(file) }': arguments[${ i }]`).join(',\n        ') }
      }
  });`;
  
  // use FP when https://github.com/lodash/lodash/pull/2503 is released
  var zipObjectDeep = require('lodash/zipObjectDeep');
  
  // Deep Formats
  var deepKeys    = _.map(_.flow(noExt, _.replace(/\//g, '.'))),
      stringify   = x => JSON.stringify(x, null, 4),
      indent      = _.replace(/\n/g, '\n    '),
      unquote     = _.replace(/"require(.*)'\)"/g, "require$1')"),
      deepify     = _.flow(zipObjectDeep, stringify, indent, unquote);
      
  metagen.formats.deepCommonJS = files => `define(function(require) {
      return ${ deepify(deepKeys(files), files.map(file => `require('${ noExt(file) }')`))};
  });`;
  metagen.formats.deepAMD = files => `define([
      ${ files.map(file => `'${ noExt(file) }'`).join(',\n    ') }
  ], function() {
      return ${ deepify(deepKeys(files), files.map((file, i) => `arguments[${ i }]`))};
  });`;
  
  module.exports = metagen;
subject: tweak regexes and wrap nested keys in quotes