fix: error reporting (#41249)

client/src/client/frame-runner.js

@@ -82,15 +82,13 @@ async function initTestFrame(e = { code: {} }) {
           try {
             // eslint-disable-next-line no-eval
             const test = eval(testString);
-            resolve({ test });
+            resolve(test);
           } catch (err) {
-            reject({ err });
+            reject(err);
           }
         })
       );
-      const { test, err } = await testPromise;
-      if (err) throw err;
-
+      const test = await testPromise;
       if (typeof test === 'function') {
         await test(e.getUserInput);
       }
@@ -99,8 +97,11 @@ async function initTestFrame(e = { code: {} }) {
       if (!(err instanceof chai.AssertionError)) {
         console.error(err);
       }
-      // return the error so that the curriculum tests are more informative
-      return { err };
+      // to provide useful debugging information when debugging the tests, we
+      // have to extract the message and stack before returning
+      return {
+        err: { message: err.message, stack: err.stack }
+      };
     }
   };
 }

curriculum/test/test-challenges.js

@@ -528,14 +528,21 @@ async function createTestRunner(
     try {
       const { pass, err } = await evaluator.evaluate(testString, 5000);
       if (!pass) {
-        throw new AssertionError(err.message);
+        throw err;
       }
     } catch (err) {
+      // add more info to the error so the failing test can be identified.
       text = 'Test text: ' + text;
-      const message = solutionFromNext
+      const newMessage = solutionFromNext
         ? 'Check next step for solution!\n' + text
         : text;
-      reThrow(err, message);
+      // if the stack is missing, the message should be included. Otherwise it
+      // is redundant.
+      err.message = err.stack
+        ? newMessage
+        : `${newMessage}
+      ${err.message}`;
+      throw err;
     }
   };
 }
@@ -578,13 +585,3 @@ async function initializeTestRunner(build, sources, code, loadEnzyme) {
     loadEnzyme
   );
 }
-
-function reThrow(err, text) {
-  const newMessage = `${text}
-  ${err.message}`;
-  if (err.name === 'AssertionError') {
-    throw new AssertionError(newMessage);
-  } else {
-    throw Error(newMessage);
-  }
-}