refactor(client): simplify sort challenge files (#59179)

Co-authored-by: Naomi <accounts+github@nhcarrigan.com>

client/utils/sort-challengefiles.test.ts

@@ -0,0 +1,30 @@
+import { challengeFiles } from './__fixtures__/challenges';
+import { sortChallengeFiles } from './sort-challengefiles';
+
+describe('sort-files', () => {
+  describe('sortChallengeFiles', () => {
+    it('should return an array', () => {
+      const sorted = sortChallengeFiles(challengeFiles);
+      expect(Array.isArray(sorted)).toBe(true);
+    });
+    it('should not modify the challenges', () => {
+      const sorted = sortChallengeFiles(challengeFiles);
+      const expected = challengeFiles;
+      expect(sorted).toEqual(expect.arrayContaining(expected));
+      expect(sorted.length).toEqual(expected.length);
+    });
+
+    it('should sort the objects into jsx, html, css, js, ts order', () => {
+      const sorted = sortChallengeFiles(challengeFiles);
+      const sortedKeys = sorted.map(({ fileKey }) => fileKey);
+      const expected = [
+        'indexjsx',
+        'indexhtml',
+        'stylescss',
+        'scriptjs',
+        'indexts'
+      ];
+      expect(sortedKeys).toStrictEqual(expected);
+    });
+  });
+});