From 0c04e1a9ed2bbe7873bfd5a4ee9d6b747b0fd1f1 Mon Sep 17 00:00:00 2001
From: Oliver Eyton-Williams <ojeytonwilliams@gmail.com>
Date: Thu, 23 Oct 2025 12:02:40 +0200
Subject: [PATCH] test: use expect for clearer errors (#62965)

---
 curriculum/package.json                |  3 +--
 curriculum/src/test/test-challenges.js | 33 ++++++++++----------------
 pnpm-lock.yaml                         |  9 +++----
 3 files changed, 16 insertions(+), 29 deletions(-)

diff --git a/curriculum/package.json b/curriculum/package.json
index 1d6e0377092..53a44e9c781 100644
--- a/curriculum/package.json
+++ b/curriculum/package.json
@@ -41,13 +41,12 @@
   "devDependencies": {
     "@babel/core": "7.23.7",
     "@babel/register": "7.23.7",
-    "@types/polka": "^0.5.7",
     "@total-typescript/ts-reset": "^0.6.1",
     "@types/debug": "^4.1.12",
     "@types/js-yaml": "4.0.5",
+    "@types/polka": "^0.5.7",
     "@types/string-similarity": "^4.0.2",
     "@vitest/ui": "^3.2.4",
-    "chai": "4.4.1",
     "glob": "8.1.0",
     "joi": "17.12.2",
     "joi-objectid": "3.0.1",
diff --git a/curriculum/src/test/test-challenges.js b/curriculum/src/test/test-challenges.js
index 22f1bda1c1f..050e700661c 100644
--- a/curriculum/src/test/test-challenges.js
+++ b/curriculum/src/test/test-challenges.js
@@ -1,5 +1,4 @@
 import { describe, it, beforeAll, expect } from 'vitest';
-import { assert, AssertionError } from 'chai';
 import jsdom from 'jsdom';
 import lodash from 'lodash';
 
@@ -151,33 +150,28 @@ function populateTestsForLang({ lang, challenges, meta }) {
               const index = meta[dashedBlockName]?.challengeOrder?.findIndex(
                 ({ id }) => id === challenge.id
               );
-
-              if (index < 0) {
-                throw new AssertionError(
-                  `Cannot find ID "${challenge.id}" in meta.json file for block "${dashedBlockName}"`
-                );
-              }
+              expect(
+                index,
+                `Cannot find ID "${challenge.id}" in meta.json file for block "${dashedBlockName}"`
+              ).toBeGreaterThanOrEqual(0);
             });
 
             it('Common checks', function () {
               const result = validateChallenge(challenge);
 
-              if (result.error) {
-                throw new AssertionError(result.error);
-              }
+              expect(result.error).toBeUndefined();
               const { id, block, dashedName } = challenge;
-              assert.exists(
-                dashedName,
-                `Missing dashedName for challenge ${id} in ${block}.`
-              );
+
+              expect(dashedName).toBeDefined();
+
               const pathAndTitle = `${block}/${dashedName}`;
               const idVerificationMessage = mongoIds.check(id, block);
-              assert.isNull(idVerificationMessage, idVerificationMessage);
+              expect(idVerificationMessage).toBeNull();
               const dupeTitleCheck = challengeTitles.check(dashedName, block);
-              assert.isTrue(
+              expect(
                 dupeTitleCheck,
                 `All challenges within a block must have a unique dashed name. ${dashedName} (at ${pathAndTitle}) is already assigned`
-              );
+              ).toBeTruthy();
             });
 
             const { challengeType } = challenge;
@@ -231,10 +225,7 @@ function populateTestsForLang({ lang, challenges, meta }) {
                   }
                 }
                 console.error = oldConsoleError;
-                assert(
-                  fails,
-                  'Test suite does not fail on the initial contents'
-                );
+                expect(fails, 'Test suite should fail on the initial contents');
               },
               timePerTest * tests.length + 20000
             );
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 09b011de58f..b9f757c822d 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -730,9 +730,6 @@ importers:
       '@vitest/ui':
         specifier: ^3.2.4
         version: 3.2.4(vitest@3.2.4)
-      chai:
-        specifier: 4.4.1
-        version: 4.4.1
       glob:
         specifier: 8.1.0
         version: 8.1.0
@@ -777,7 +774,7 @@ importers:
         version: 4.0.4
       vitest:
         specifier: ^3.2.4
-        version: 3.2.4(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@16.7.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.8.2))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.0)
+        version: 3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@16.7.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.8.2))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.0)
 
   shared:
     devDependencies:
@@ -20163,7 +20160,7 @@ snapshots:
       sirv: 3.0.2
       tinyglobby: 0.2.14
       tinyrainbow: 2.0.0
-      vitest: 3.2.4(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@26.1.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.7.3))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.0)
+      vitest: 3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@16.7.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.8.2))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.0)
 
   '@vitest/utils@3.2.4':
     dependencies:
@@ -31143,7 +31140,7 @@ snapshots:
       - debug
       - typescript
 
-  vitest@3.2.4(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@16.7.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.8.2))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.0):
+  vitest@3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@16.7.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.8.2))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.0):
     dependencies:
       '@types/chai': 5.2.2
       '@vitest/expect': 3.2.4