From 44c43e3c0a6f02018792686732c0fd1edd3ccbc0 Mon Sep 17 00:00:00 2001
From: Oliver Eyton-Williams <ojeytonwilliams@gmail.com>
Date: Mon, 10 Mar 2025 06:54:37 +0100
Subject: [PATCH] refactor: simplify test-evaluator (#59037)

---
 .../browser-scripts/test-evaluator.ts         | 33 ++++++++++---------
 1 file changed, 18 insertions(+), 15 deletions(-)

diff --git a/tools/client-plugins/browser-scripts/test-evaluator.ts b/tools/client-plugins/browser-scripts/test-evaluator.ts
index 1508457a3bf..3dd42108cc3 100644
--- a/tools/client-plugins/browser-scripts/test-evaluator.ts
+++ b/tools/client-plugins/browser-scripts/test-evaluator.ts
@@ -1,6 +1,6 @@
 import chai from 'chai';
 import { toString as __toString } from 'lodash-es';
-import * as helpers from '@freecodecamp/curriculum-helpers';
+import * as curriculumHelpers from '@freecodecamp/curriculum-helpers';
 import { format as __format } from './utils/format';
 
 const ctx: Worker & typeof globalThis = self as unknown as Worker &
@@ -80,10 +80,23 @@ const __utils = (() => {
   };
 })();
 
-// We freeze these two to prevent learners from getting the tester into a weird
-// state.
+// Fake Deep Equal dependency
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+const DeepEqual = (a: unknown, b: unknown) =>
+  JSON.stringify(a) === JSON.stringify(b);
+
+// We can't simply import these because of how webpack names them when building
+// the bundle. Since both assert and __helpers have to exist in the global
+// scope, we have to declare them.
+const assert = chai.assert;
+const __helpers = curriculumHelpers;
+
+// We freeze to prevent learners from getting the tester into a weird
+// state by modifying these objects.
 Object.freeze(self);
 Object.freeze(__utils);
+Object.freeze(assert);
+Object.freeze(__helpers);
 
 interface TestEvaluatorEvent extends MessageEvent {
   data: {
@@ -104,18 +117,8 @@ interface TestEvaluatorEvent extends MessageEvent {
 /* Run the test if there is one.  If not just evaluate the user code */
 ctx.onmessage = async (e: TestEvaluatorEvent) => {
   /* eslint-disable @typescript-eslint/no-unused-vars */
-  const code = (e.data?.code?.contents || '').slice();
-  const editableContents = (e.data?.code?.editableContents || '').slice();
-
-  const assert = chai.assert;
-  const __helpers = helpers;
-  // Similarly to self and __utils, if the learner tries to modify these, weird
-  // behavior may result. Freezing them means they get an error instead.
-  Object.freeze(assert);
-  Object.freeze(__helpers);
-  // Fake Deep Equal dependency
-  const DeepEqual = (a: unknown, b: unknown) =>
-    JSON.stringify(a) === JSON.stringify(b);
+  const code = e.data?.code?.contents || '';
+  const editableContents = e.data?.code?.editableContents || '';
 
   // Build errors should be reported, but only once:
   __utils.toggleProxyLogger(e.data.firstTest);