old_contents: var request = require('axios')
  
  var WebpackFeatures = function(featuresContext) {
      this.each = function(fn) {
          this.list().then(function(files) {
              files.forEach(fn)
          })
      }
  
      this.list = function() {
          var pendingRequests = []
          var featureFilenames = featuresContext.keys()
  
          featureFilenames.forEach(function(f, i) {
              var req = request.get(featuresContext(f))
  
              pendingRequests.push(req)
          })
  
          return request.all(pendingRequests).then(request.spread(this.handleResponse))
      }
  
      this.handleResponse = function() {
          var args = Array.prototype.slice.call(arguments);
          var files = []
  
          if (typeof args[0] === 'object') {
              files = args.map(function(arg) {
                  return arg[0]
              })
          } else {
              files = [args[0]]
          }
  
          return files
      }
  }
  
  module.exports = WebpackFeatures
  
new_contents: var request = require('axios')
  
  var WebpackFeatures = function(featuresContext) {
      this.each = function(fn) {
          this.list().then(function() {
              var files = arguments[0]
              files.forEach(fn)
          })
      }
  
      this.list = function() {
          var pendingRequests = []
          var featureFilenames = featuresContext.keys()
  
          featureFilenames.forEach(function(f, i) {
              var req = request.get(featuresContext(f))
  
              pendingRequests.push(req)
          })
  
          var all = request.all(pendingRequests).then(this.handleResponse)
          return all
      }
  
      this.handleResponse = function() {
          var args = Array.prototype.slice.call(arguments)
          var responses = args[0]
          var files = responses.map(function(f) {
              return f.data
          })
  
          return files
      }
  }
  
  module.exports = WebpackFeatures
  
subject: Fix bug when processing ajax response