feat(client): make all sources available in tests (#44725)

* feat: make all sources available in tests

The original contents of all files (index.html, script.js etc.) will be
accessible in tests.  For example __sources['index.html'] gets the
original html file and nothing else.

* feat: use __file to get user code

client/src/templates/Challenges/utils/build.js

@@ -47,10 +47,12 @@ function buildSourceMap(challengeFiles) {
   const source = challengeFiles.reduce(
     (sources, challengeFile) => {
       sources.index += challengeFile.source || challengeFile.contents;
+      sources.contents = sources.index;
+      sources.original[challengeFile.history[0]] = challengeFile.source;
       sources.editableContents += challengeFile.editableContents || '';
       return sources;
     },
-    { index: '', editableContents: '' }
+    { index: '', editableContents: '', original: {} }
   );
   return source;
 }

client/src/templates/Challenges/utils/frame.js

@@ -111,15 +111,13 @@ const initTestFrame = frameReady => ctx => {
   waitForFrame(ctx)
     .then(async () => {
       const { sources, loadEnzyme } = ctx;
-      // default for classic challenges
-      // should not be used for modern
-      const code = {
-        contents: sources.index,
-        editableContents: sources.editableContents
-      };
       // provide the file name and get the original source
       const getUserInput = fileName => toString(sources[fileName]);
-      await ctx.document.__initTestFrame({ code, getUserInput, loadEnzyme });
+      await ctx.document.__initTestFrame({
+        code: sources,
+        getUserInput,
+        loadEnzyme
+      });
       frameReady();
     })
     .catch(handleDocumentNotFound);