super ugly, but added jslinting

client/modules/IDE/components/Editor.js

@@ -2,6 +2,10 @@ import React, { PropTypes } from 'react';
 import CodeMirror from 'codemirror';
 import 'codemirror/mode/javascript/javascript';
 import 'codemirror/addon/selection/active-line';
+import 'codemirror/addon/lint/lint';
+import 'codemirror/addon/lint/javascript-lint';
+import { JSHINT } from 'jshint';
+window.JSHINT = JSHINT;
 
 class Editor extends React.Component {
 
@@ -12,7 +16,9 @@ class Editor extends React.Component {
       lineNumbers: true,
       styleActiveLine: true,
       mode: 'javascript',
-      lineWrapping: true
+      lineWrapping: true,
+      gutters: ['CodeMirror-lint-markers'],
+      lint: true
     });
     this._cm.on('change', () => { // eslint-disable-line
       // this.props.updateFileContent('sketch.js', this._cm.getValue());

client/styles/main.scss

@@ -5,6 +5,7 @@
 @import 'base/base';
 
 @import 'vendors/codemirror';
+@import 'vendors/lint';
 
 @import 'components/p5-widget-codemirror-theme';
 @import 'components/editor';

client/styles/vendors/_lint.scss

@@ -0,0 +1,73 @@
+/* The lint marker gutter */
+.CodeMirror-lint-markers {
+  width: 16px;
+}
+
+.CodeMirror-lint-tooltip {
+  background-color: infobackground;
+  border: 1px solid black;
+  border-radius: 4px 4px 4px 4px;
+  color: infotext;
+  font-family: monospace;
+  font-size: 10pt;
+  overflow: hidden;
+  padding: 2px 5px;
+  position: fixed;
+  white-space: pre;
+  white-space: pre-wrap;
+  z-index: 100;
+  max-width: 600px;
+  opacity: 0;
+  transition: opacity .4s;
+  -moz-transition: opacity .4s;
+  -webkit-transition: opacity .4s;
+  -o-transition: opacity .4s;
+  -ms-transition: opacity .4s;
+}
+
+.CodeMirror-lint-mark-error, .CodeMirror-lint-mark-warning {
+  background-position: left bottom;
+  background-repeat: repeat-x;
+}
+
+.CodeMirror-lint-mark-error {
+  background-image:
+  url("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAQAAAADCAYAAAC09K7GAAAAAXNSR0IArs4c6QAAAAZiS0dEAP8A/wD/oL2nkwAAAAlwSFlzAAALEwAACxMBAJqcGAAAAAd0SU1FB9sJDw4cOCW1/KIAAAAZdEVYdENvbW1lbnQAQ3JlYXRlZCB3aXRoIEdJTVBXgQ4XAAAAHElEQVQI12NggIL/DAz/GdA5/xkY/qPKMDAwAADLZwf5rvm+LQAAAABJRU5ErkJggg==")
+  ;
+}
+
+.CodeMirror-lint-mark-warning {
+  background-image: url("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAQAAAADCAYAAAC09K7GAAAAAXNSR0IArs4c6QAAAAZiS0dEAP8A/wD/oL2nkwAAAAlwSFlzAAALEwAACxMBAJqcGAAAAAd0SU1FB9sJFhQXEbhTg7YAAAAZdEVYdENvbW1lbnQAQ3JlYXRlZCB3aXRoIEdJTVBXgQ4XAAAAMklEQVQI12NkgIIvJ3QXMjAwdDN+OaEbysDA4MPAwNDNwMCwiOHLCd1zX07o6kBVGQEAKBANtobskNMAAAAASUVORK5CYII=");
+}
+
+.CodeMirror-lint-marker-error, .CodeMirror-lint-marker-warning {
+  background-position: center center;
+  background-repeat: no-repeat;
+  cursor: pointer;
+  display: inline-block;
+  height: 16px;
+  width: 16px;
+  vertical-align: middle;
+  position: relative;
+}
+
+.CodeMirror-lint-message-error, .CodeMirror-lint-message-warning {
+  padding-left: 18px;
+  background-position: top left;
+  background-repeat: no-repeat;
+}
+
+.CodeMirror-lint-marker-error, .CodeMirror-lint-message-error {
+  background-image: url("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAMAAAAoLQ9TAAAAHlBMVEW7AAC7AACxAAC7AAC7AAAAAAC4AAC5AAD///+7AAAUdclpAAAABnRSTlMXnORSiwCK0ZKSAAAATUlEQVR42mWPOQ7AQAgDuQLx/z8csYRmPRIFIwRGnosRrpamvkKi0FTIiMASR3hhKW+hAN6/tIWhu9PDWiTGNEkTtIOucA5Oyr9ckPgAWm0GPBog6v4AAAAASUVORK5CYII=");
+}
+
+.CodeMirror-lint-marker-warning, .CodeMirror-lint-message-warning {
+  background-image: url("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAMAAAAoLQ9TAAAANlBMVEX/uwDvrwD/uwD/uwD/uwD/uwD/uwD/uwD/uwD6twD/uwAAAADurwD2tQD7uAD+ugAAAAD/uwDhmeTRAAAADHRSTlMJ8mN1EYcbmiixgACm7WbuAAAAVklEQVR42n3PUQqAIBBFUU1LLc3u/jdbOJoW1P08DA9Gba8+YWJ6gNJoNYIBzAA2chBth5kLmG9YUoG0NHAUwFXwO9LuBQL1giCQb8gC9Oro2vp5rncCIY8L8uEx5ZkAAAAASUVORK5CYII=");
+}
+
+.CodeMirror-lint-marker-multiple {
+  background-image: url("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAcAAAAHCAMAAADzjKfhAAAACVBMVEUAAAAAAAC/v7914kyHAAAAAXRSTlMAQObYZgAAACNJREFUeNo1ioEJAAAIwmz/H90iFFSGJgFMe3gaLZ0od+9/AQZ0ADosbYraAAAAAElFTkSuQmCC");
+  background-repeat: no-repeat;
+  background-position: right bottom;
+  width: 100%; height: 100%;
+}

package.json

@@ -70,6 +70,7 @@
     "eslint-loader": "^1.3.0",
     "express": "^4.13.4",
     "express-session": "^1.13.0",
+    "jshint": "^2.9.2",
     "moment": "^2.14.1",
     "mongoose": "^4.4.16",
     "passport": "^0.3.2",