diff --git a/client/commonFramework/add-faux-stream.js b/client/commonFramework/add-faux-stream.js
index c25f69f75b..17a57e212c 100644
--- a/client/commonFramework/add-faux-stream.js
+++ b/client/commonFramework/add-faux-stream.js
@@ -1,35 +1,22 @@
 window.common = (function(global) {
   const {
-    $,
-    Rx: { Observable, Disposable },
     common = { init: [] }
   } = global;
 
 
-  function getFaux() {
-    return new Observable(function(observer) {
-      const jqXHR = $.get('/js/faux.js')
-        .success(data => observer.onNext(data))
-        .fail(e => observer.onError(e))
-        .always(() => observer.onCompleted());
+  const faux$ = common.getScriptContent$('/js/faux.js').shareReplay();
 
-      return new Disposable(() => {
-        jqXHR.abort();
-      });
-    });
-  }
-
-  const faux$ = getFaux().shareReplay();
-
-  common.safeHTMLRun = function safeHTMLRun(code) {
-    if (!code.match(/\<script\>/gi)) {
-      return Observable.just(code);
-    }
+  common.hasJs = function hasJs(code = '') {
+    return code.match(/\<\s?script\s?\>/gi) &&
+      code.match(/\<\s?\/\s?script\s?\>/gi);
+  };
 
+  common.addFaux$ = function addFaux$(code) {
     // grab user javaScript
     var scriptCode = code
       .split(/\<\s?script\s?\>/gi)[1]
       .split(/\<\s?\/\s?script\s?\>/gi)[0];
+
     return faux$.map(faux => faux + scriptCode);
   };
 
diff --git a/client/commonFramework/end.js b/client/commonFramework/end.js
index 3f2dbdd689..7fa85bb830 100644
--- a/client/commonFramework/end.js
+++ b/client/commonFramework/end.js
@@ -71,24 +71,24 @@ $(document).ready(function() {
       }
     );
 
-  var $preview = $('#preview');
-  if ($preview.html()) {
-    $preview.load(function() {
-      common.executeChallenge()
-        .subscribe(
-          ({ output = '' }) => {
-            common.updateOutputDisplay(output);
-          },
-          ({ err }) => {
-            common.updateOutputDisplay('' + err);
-          }
-        );
-    });
-  } else if (
-    challengeType !== '2' &&
-    challengeType !== '3' &&
-    challengeType !== '4' &&
-    challengeType !== '7'
+  if (challengeType === challengeTypes.HTML) {
+    var $preview = $('#preview');
+    return Observable.fromCallback($preview.ready, $preview)()
+      .delay(500)
+      .flatMap(() => common.executeChallenge$())
+      .subscribe(
+        ({ code, tests }) => {
+          common.displayTestResults(tests);
+        },
+        ({ err }) => {
+          console.error(err);
+        }
+      );
+  }
+
+  if (
+    challengeType === challengeTypes.BONFIRE &&
+    challengeType === challengeTypes.JS
   ) {
     Observable.just({})
       .delay(500)
diff --git a/client/commonFramework/execute-challenge-stream.js b/client/commonFramework/execute-challenge-stream.js
index dfcfdf0d9e..57196e2312 100644
--- a/client/commonFramework/execute-challenge-stream.js
+++ b/client/commonFramework/execute-challenge-stream.js
@@ -84,9 +84,28 @@ window.common = (function(global) {
         // add head and tail and detect loops
         return Observable.just({ code: head + code + tail, original: code });
       })
-      .map(data => {
+      .flatMap(data => {
         if (common.challengeType === common.challengeTypes.HTML) {
-          return common.getScriptCode(data);
+
+          if (common.hasJs(code)) {
+            return common.addFaux$(data)
+              .flatMap(code => common.detectLoops$(code))
+              .flatMap(({ err }) => {
+                if (err) {
+                  return Observable.throw({ err });
+                }
+                return common.runPreviewTests$({
+                  code: data.code,
+                  tests: common.tests.slice()
+                });
+              });
+          }
+
+          return common.updatePreview$(data.code)
+            .flatMap(code => common.runPreviewTests$({
+              code,
+              tests: common.tests.slice()
+            }));
         }
 
         return common.addTestsToString(Object.assign(
@@ -95,21 +114,21 @@ window.common = (function(global) {
             code: common.removeComments(code),
             tests: common.tests.slice()
           }
-        ));
-      })
-      .flatMap(common.detectLoops$)
-      .flatMap(({ err, code, data, userTests, original }) => {
-          if (err) {
-            return Observable.throw({ err });
-          }
+        ))
+        .flatMap(common.detectLoops$)
+        .flatMap(({ err, code, data, userTests, original }) => {
+            if (err) {
+              return Observable.throw({ err });
+            }
 
-          return common.runTests$({
-            data,
-            code,
-            userTests,
-            original,
-            output: data.output.replace(/\\\"/gi, '')
-          });
+            return common.runTests$({
+              data,
+              code,
+              userTests,
+              original,
+              output: data.output.replace(/\\\"/gi, '')
+            });
+        });
       })
       .catch(e => {
         return e && e.err ?
diff --git a/client/commonFramework/init.js b/client/commonFramework/init.js
index 05bf8a520e..152bc3b71e 100644
--- a/client/commonFramework/init.js
+++ b/client/commonFramework/init.js
@@ -3,7 +3,7 @@ window.common = (function(global) {
   // all classes should be stored here
   // called at the beginning of dom ready
   const {
-    Rx: { config },
+    Rx: { Disposable, Observable, config },
     common = { init: [] }
   } = global;
 
@@ -86,5 +86,21 @@ window.common = (function(global) {
     return code.replace(regexp, text);
   };
 
+  common.getScriptContent$ = function getScriptContent$(script) {
+    return Observable.create(function(observer) {
+      const jqXHR = $.get(script)
+        .success(data => {
+          observer.onNext(data);
+          observer.onCompleted();
+        })
+        .fail(e => observer.onError(e))
+        .always(() => observer.onCompleted());
+
+      return new Disposable(() => {
+        jqXHR.abort();
+      });
+    });
+  };
+
   return common;
 })(window);
diff --git a/client/commonFramework/output-display.js b/client/commonFramework/output-display.js
index 3220510db8..7850435317 100644
--- a/client/commonFramework/output-display.js
+++ b/client/commonFramework/output-display.js
@@ -5,12 +5,12 @@ window.common = (function(global) {
     common = { init: [] }
   } = global;
 
-  const { challengeType = '0' } = common;
+  const { challengeTypes, challengeType = '0' } = common;
 
   if (
     !CodeMirror ||
-    challengeType === '0' ||
-    challengeType === '7'
+    challengeType !== challengeTypes.JS ||
+    challengeType !== challengeTypes.BONFIRE
   ) {
     common.updateOutputDisplay = () => {};
     common.appendToOutputDisplay = () => {};
diff --git a/client/commonFramework/update-preview.js b/client/commonFramework/update-preview.js
index 3608a65bd8..d6ee1a0743 100644
--- a/client/commonFramework/update-preview.js
+++ b/client/commonFramework/update-preview.js
@@ -1,4 +1,4 @@
-window.common = (function({ common = { init: [] } }) {
+window.common = (function({ Rx: { Observable }, common = { init: [] } }) {
   var libraryIncludes = `
 <link
   rel='stylesheet'
@@ -19,21 +19,29 @@ window.common = (function({ common = { init: [] } }) {
 </style>
   `;
 
-  var iFrameScript = "<script src='/js/iFrameScripts.js'></script>";
+  const iFrameScript$ =
+    common.getScriptContent$('/js/iFrameScripts.js').shareReplay();
 
+  // runPreviewTests$ should be set up in the preview window
+  common.runPreviewTests$ =
+    () => Observable.throw({ err: new Error('run preview not enabled') });
 
-  common.updatePreview = function updatePreview(code = '', shouldTest = false) {
+  common.updatePreview$ = function updatePreview$(code = '') {
     const previewFrame = document.getElementById('preview');
     const preview = previewFrame.contentDocument ||
       previewFrame.contentWindow.document;
     if (!preview) {
-      return code;
+      return Observable.just(code);
     }
-    preview.open();
-    preview.write(libraryIncludes + code + (shouldTest ? iFrameScript : ''));
-    preview.close();
 
-    return code;
+    return iFrameScript$
+      .map(script => `<script>${script}</script>`)
+      .doOnNext(script => {
+        preview.open();
+        preview.write(libraryIncludes + code + script);
+        preview.close();
+      })
+      .map(() => code);
   };
 
   return common;
diff --git a/client/iFrameScripts.js b/client/iFrameScripts.js
index 66cb8554ba..5fbf663a11 100644
--- a/client/iFrameScripts.js
+++ b/client/iFrameScripts.js
@@ -2,27 +2,36 @@
 window.$ = parent.$;
 window.$(function() {
   var _ = parent._;
+  var Rx = parent.Rx;
   var chai = parent.chai;
-  var expect = chai.expect;
+  var assert = chai.assert;
   var tests = parent.tests;
   var common = parent.common;
-  var editorValue = common.editor.getValue();
+  var code = common.editor.getValue();
   var editor = common.editor;
 
-  var userTests = common.tests.map(test => {
-    var userTest = {};
-    try {
-      /* eslint-disable no-eval */
-      eval(test);
-      /* eslint-enable no-eval */
-    } catch (e) {
-      userTest.err = e.message.split(':').shift();
-    } finally {
-      userTest.text = test
-        .split(',')
-        .pop()
-        .replace(/\'/g, '')
-        .replace(/\)/, '');
-    }
-  });
+  common.runPreviewTests$ =
+    function runPreviewTests$({ tests = [], ...rest }) {
+      return Rx.Observable.from(tests)
+        .map(test => {
+          const userTest = {};
+          try {
+            /* eslint-disable no-eval */
+            eval(test);
+            /* eslint-enable no-eval */
+          } catch (e) {
+            userTest.err = e.message.split(':').shift();
+          } finally {
+            userTest.text = test
+              .split(',')
+              .pop()
+              .replace(/\'/g, '')
+              .replace(/\)/, '');
+          }
+          return userTest;
+        })
+        .toArray()
+        .map(tests => ({ ...rest, tests }));
+    };
+
 });