diff --git a/client/frame-runner.js b/client/frame-runner.js
index 19da925dff..3411a790a0 100644
--- a/client/frame-runner.js
+++ b/client/frame-runner.js
@@ -73,31 +73,18 @@ document.addEventListener('DOMContentLoaded', function() {
           /* eslint-enable no-eval */
           if (typeof test === 'function') {
 
-            // we know that the test eval'ed to a function
-            // the function could expect a callback
-            // or it could return a promise/observable
-            // or it could still be sync
-            if (test.length === 1) {
-              // a function with length 0 means it expects 0 args
-              // We call it and store the result
-              // This result may be a promise or an observable or undefined
-              __result = test(getUserInput);
-            } else {
-              // if function takes arguments
-              // we expect it to be of the form
-              // function(cb) { /* ... */ }
-              // and callback has the following signature
-              // function(err) { /* ... */ }
-              __result = Rx.Observable.fromNodeCallback(test)(getUserInput);
-            }
+            // all async tests must return a promise or observable
+            // sync tests can return Any type
+            __result = test(getUserInput);
 
             if (helpers.isPromise(__result)) {
               // turn promise into an observable
               __result = Rx.Observable.fromPromise(__result);
             }
-          } else {
-            // test is not a function
-            // fill result with for compatibility
+          }
+
+          if (!__result || typeof __result.subscribe !== 'function') {
+            // make sure result is an observable
             __result = Rx.Observable.of(null);
           }
         } catch (e) {
diff --git a/common/app/routes/Challenges/rechallenge/transformers.js b/common/app/routes/Challenges/rechallenge/transformers.js
index 34eed3a746..4f6ae3e64a 100644
--- a/common/app/routes/Challenges/rechallenge/transformers.js
+++ b/common/app/routes/Challenges/rechallenge/transformers.js
@@ -5,11 +5,7 @@ import presetEs2015 from 'babel-preset-es2015';
 import presetReact from 'babel-preset-react';
 import { Observable } from 'rx';
 
-import {
-  transformHeadTailAndContents,
-  setContent,
-  setExt
-} from '../../../../utils/polyvinyl.js';
+import * as vinyl from '../../../../utils/polyvinyl.js';
 import castToObservable from '../../../utils/cast-to-observable.js';
 
 const babelOptions = { presets: [ presetEs2015, presetReact ] };
@@ -35,43 +31,47 @@ const testJS$JSX = _.overSome(isJS, _.matchesProperty('ext', 'jsx'));
 // to `window.__console.log`
 // this let's us tap into logging into the console.
 // currently we only do this to the main window and not the test window
-export function proxyLoggerTransformer(file) {
-  return transformHeadTailAndContents(
-    (source) => (
+export const proxyLoggerTransformer = _.partial(
+  vinyl.transformHeadTailAndContents,
+  source => (
       source.replace(console$logReg, (match, methodCall) => {
       return 'window.__console' + methodCall;
-    })),
-    file
-  );
-}
+  })),
+);
 
-export const addLoopProtect = _.cond([
+const addLoopProtect = _.partial(
+  vinyl.transformContents,
+  contents => {
+    /* eslint-disable import/no-unresolved */
+    const loopProtect = require('loop-protect');
+    /* eslint-enable import/no-unresolved */
+    loopProtect.hit = loopProtectHit;
+    return loopProtect(contents);
+  }
+);
+
+export const addLoopProtectHtmlJsJsx = _.cond([
   [
-    testHTMLJS,
-    function(file) {
-      const _contents = file.contents.toLowerCase();
-      if (file.ext === 'html' && !_contents.indexOf('<script>') !== -1) {
-        // No JavaScript in user code, so no need for loopProtect
-        return file;
-      }
-      /* eslint-disable import/no-unresolved */
-      const loopProtect = require('loop-protect');
-      /* eslint-enable import/no-unresolved */
-      loopProtect.hit = loopProtectHit;
-      return setContent(loopProtect(file.contents), file);
-    }
+    _.overEvery(
+      testHTMLJS,
+      _.partial(
+        vinyl.testContents,
+        contents => contents.toLowerCase().contians('<script>')
+      )
+    ),
+    addLoopProtect
   ],
+  [ testJS$JSX, addLoopProtect ],
   [ _.stubTrue, _.identity ]
 ]);
+
 export const replaceNBSP = _.cond([
   [
     testHTMLJS,
-    function(file) {
-      return setContent(
-        file.contents.replace(NBSPReg, ' '),
-        file
-      );
-    }
+    _.partial(
+      vinyl.transformContents,
+      contents => contents.replace(NBSPReg, ' ')
+    )
   ],
   [ _.stubTrue, _.identity ]
 ]);
@@ -79,19 +79,19 @@ export const replaceNBSP = _.cond([
 export const babelTransformer = _.cond([
   [
     testJS$JSX,
-    function(file) {
-      const result = babel.transform(file.contents, babelOptions);
-      return _.flow(
-        _.partial(setContent, result.code),
-        _.partial(setExt, 'js')
-      )(file);
-    }
+    _.flow(
+      _.partial(
+        vinyl.transformContents,
+        contents => babel.transform(contents, babelOptions).code
+      ),
+      _.partial(vinyl.setExt, 'js')
+    )
   ],
   [ _.stubTrue, _.identity ]
 ]);
 
 export const _transformers = [
-  addLoopProtect,
+  addLoopProtectHtmlJsJsx,
   replaceNBSP,
   babelTransformer
 ];
diff --git a/common/app/routes/Challenges/utils/frame.js b/common/app/routes/Challenges/utils/frame.js
index a785b508e5..8ae321b7ea 100644
--- a/common/app/routes/Challenges/utils/frame.js
+++ b/common/app/routes/Challenges/utils/frame.js
@@ -101,7 +101,8 @@ const writeTestDepsToDocument = frameReady => ctx => {
   // default for classic challenges
   // should not be used for modern
   tests.__source = sources['index'] || '';
-  tests.__getUserInput = key => sources[key];
+  // provide the file name and get the original source
+  tests.__getUserInput = fileName => _.toString(sources[fileName]);
   tests.__checkChallengePayload = checkChallengePayload;
   tests.__frameReady = frameReady;
   return ctx;
diff --git a/common/utils/polyvinyl.js b/common/utils/polyvinyl.js
index 68fdf8f723..460abc8e05 100644
--- a/common/utils/polyvinyl.js
+++ b/common/utils/polyvinyl.js
@@ -168,8 +168,8 @@ export function clearHeadTail(poly) {
 
 // compileHeadTail(contents: String, poly: PolyVinyl) => PolyVinyl
 export function compileHeadTail(padding = '', poly) {
-  return clearHeadTail(setContent(
-    [ poly.head, poly.contents, poly.tail ].join(padding),
+  return clearHeadTail(transformContents(
+    () => [ poly.head, poly.contents, poly.tail ].join(padding),
     poly
   ));
 }
@@ -188,7 +188,7 @@ export function transformContents(wrap, poly) {
     poly
   );
   // if no source exist, set the original contents as source
-  newPoly.source = poly.contents || poly.contents;
+  newPoly.source = poly.source || poly.contents;
   return newPoly;
 }
 
@@ -206,3 +206,7 @@ export function transformHeadTailAndContents(wrap, poly) {
     tail: wrap(poly.tail)
   };
 }
+
+export function testContents(predicate, poly) {
+  return !!predicate(poly.contents);
+}
diff --git a/seed/challenges/03-front-end-libraries/react.json b/seed/challenges/03-front-end-libraries/react.json
index fc6adf8d7a..ee7019b995 100644
--- a/seed/challenges/03-front-end-libraries/react.json
+++ b/seed/challenges/03-front-end-libraries/react.json
@@ -27,7 +27,7 @@
           "name": "index",
           "contents": [
             "",
-            "var jsx = <div></div>;",
+            "const jsx = <div></div>;",
             ""
           ]
         }
@@ -39,6 +39,40 @@
       "type": "modern",
       "isRequired": false,
       "translations": {}
+    },
+    {
+      "id": "5a24c314108439a4d4036168",
+      "title": "Write a React Component from Scratch",
+      "releasedOn": "December 25, 2017",
+      "description": [
+        "Now that you've learned the basics of JSX and React components, it's time to write a component on your own. React components are the core building blocks of React applications so it's important to become very familiar with writing them. Remember, a typical React component is an ES6 <code>class</code> which extends <code>React.Component</code>. It has a render method that returns HTML (from JSX) or <code>null</code>. This is the basic form of a React component. Once you understand this well, you will be prepared to start building more complex React projects.",
+        "<hr>",
+        "Define a class <code>MyComponent</code> that extends <code>React.Component</code>. Its render method should return a <code>div</code> that contains an <code>h1</code> tag with the text: <code>My First React Component!</code> in it. Use this text exactly, the case and punctuation matter. Make sure to call the constructor for your component, too.",
+        "Render this component to the DOM using <code>ReactDOM.render()</code>. There is a <code>div</code> with <code>id='challenge-node'</code> available for you to use."
+      ],
+      "files": {
+        "indexjsx": {
+          "key": "indexjsx",
+          "ext": "jsx",
+          "name": "index",
+          "contents": [
+            "// change code below this line",
+            ""
+          ]
+        }
+      },
+      "backup-tests": [
+        "(getUserInput) => assert(getUserInput('index').replace(/\\s/g, '').includes('classMyComponentextendsReact.Component{'), 'message: There should be a React component called MyComponent')"
+      ],
+      "head": [],
+      "tail": [],
+      "solutions": [
+        "// change code below this line\nclass MyComponent extends React.Component {\n  constructor(props) {\n    super(props);\n  }\n  render() {\n    return (\n      <div>\n        <h1>My First React Component!</h1>\n      </div>\n    );\n  }\n};\n\nReactDOM.render(<MyComponent />, document.getElementById('challenge-node'));"
+      ],
+      "type": "modern",
+      "isRequired": false,
+      "translations": {},
+      "react": true
     }
   ]
 }