and for model destory TODO polyfill TODO mixin

src/__tests__/casperjs/command_view_test.js

@@ -0,0 +1,48 @@
+var CasperUtils = require('./casperUtils').CasperUtils;
+
+casper.start(
+  CasperUtils.getUrlForCommands([
+    'asd'
+  ]),
+  function() {
+    this.test.assertTitle('Learn Git Branching');
+
+    casper.waitFor(CasperUtils.waits.jsMount)
+    .wait(300)
+    .then(CasperUtils.screenshot.entirePage)
+    .then(CasperUtils.enterCommand('git checkout C1'))
+    .wait(800)
+    .then(CasperUtils.asserts.selectorContainsText(
+      'div.modalView.inFront div.toolbar',
+      'Select a level'
+    ))
+    .then(CasperUtils.asserts.selectorContainsText(
+      'div.modalView.inFront div.displayName h3',
+      'Introduction Sequence'
+    ))
+    .then(CasperUtils.asserts.selectorContainsText(
+      'div.modalView.inFront div.seriesView p',
+      "A nicely paced introduction to the majority of git commands"
+    ))
+    .then(function() {
+      this.page.sendEvent('keypress', this.page.event.key.Right);
+    })
+    .wait(700)
+    .then(CasperUtils.screenshot.entirePage)
+    // Now we have selected the first level
+    .then(CasperUtils.asserts.selectorContainsText(
+      'div.modalView.inFront div.seriesView p',
+      "Introduction to Git Commits"
+    ))
+    .then(function() {
+      this.page.sendEvent('keypress', this.page.event.key.Enter);
+    })
+    .wait(700)
+    .then(CasperUtils.screenshot.entirePage)
+    .then(CasperUtils.asserts.selectorContainsText(
+      'div.levelNameWrapper',
+      "Level Introduction to Git Commits"
+    ))
+    .then(CasperUtils.testDone);
+
+}).run();

src/js/models/commandModel.js

@@ -201,7 +201,6 @@ var Command = Backbone.Model.extend({
   },
 
   addWarning: function(msg) {
-    console.log('this is the warning', msg);
     this.get('warnings').push(msg);
     // change numWarnings so the change event fires. This is bizarre -- Backbone can't
     // detect if an array changes, so adding an element does nothing

src/js/react_views/CommandView.jsx

@@ -18,11 +18,17 @@ var CommandView = React.createClass({
 
   componentDidMount: function() {
     this.props.command.on('change', this.updateStateFromModel, this);
+    this.props.command.on('destroy', this.onModelDestroy, this);
     this.updateStateFromModel();
   },
 
   componentWillUnmount: function() {
     this.props.command.off('change', this.updateStateFromModel, this);
+    this.props.command.off('destroy', this.onModelDestroy, this);
+  },
+
+  onModelDestroy: function() {
+    React.unmountComponentAtNode(this.getDOMNode().parentNode);
   },
 
   updateStateFromModel: function() {