A simple js include

modules.json

[
  "js/util/dom-creator.js",
  "js/main.js"
]

simple-modules.js

/*
 * Usage:
 *  <script data-modules='modules.json' src='js/simple-modules.js' type='text/javascript'></script>
 * Will load all js files specified in modules.json array:
 * 
 */
(function(){
  var $src = document.querySelector("script[data-modules]");
  var mods = $src.dataset["modules"].split(",");
··
  var url;
  for(var i=0; i < mods.length; i++) {
    url = mods[i].trim();
    if(url.indexOf(".json") !== -1){
      load_json(url);
    }else{
      load_js(url);
    }
  }

  function load_js(url) {
    var script = document.createElement("script");
    script.type ="text/javascript"
    script.src = url;
    $src.parentElement.appendChild(script)
  }

  function load_json(url) {
    var handleJSON = function handleJSON(data){
      for(var i=0; i < data.length; i++){
        load_js(data[i]);
      }
    }

    getJSON(url, handleJSON);
  }

  //From: https://mathiasbynens.be/notes/xhr-responsetype-json
  function getJSON(url, successHandler, errorHandler) {
    var xhr = new XMLHttpRequest();
    xhr.open('get', url, true);
    xhr.responseType = 'json';
    xhr.onload = function() {
      var status = xhr.status;
      if (status == 200) {
        successHandler && successHandler(xhr.response);
      } else {
        errorHandler && errorHandler(status);
      }
    };
    xhr.send();
  };·
})();