Fix: Exercice saving validation error (#774)

Fixed the error that keeps previous deleted questions before saving

Co-authored-by: Rotimi Best <best@classroomio.com>

apps/dashboard/src/lib/features/course/components/exercise/store.test.ts

@@ -0,0 +1,41 @@
+import { describe, expect, it } from 'vitest';
+
+import type { Question } from '$features/course/types';
+import { mapZodErrorsToQuestionErrors } from './store';
+
+function makeQuestion(overrides: Partial<Question>): Question {
+  return {
+    id: overrides.id ?? 'question-1',
+    title: overrides.title ?? 'Question',
+    points: overrides.points ?? 1,
+    questionTypeId: overrides.questionTypeId ?? 1,
+    questionType: overrides.questionType,
+    options: overrides.options ?? [],
+    ...overrides
+  } as Question;
+}
+
+describe('mapZodErrorsToQuestionErrors', () => {
+  it('maps Zod question errors to the correct active question when deleted questions are present', () => {
+    const questions = [
+      makeQuestion({ id: 'question-1', title: 'Saved question 1' }),
+      makeQuestion({ id: 'question-2', title: 'Deleted question', deletedAt: '2026-01-01T00:00:00.000Z' }),
+      makeQuestion({ id: 'question-3', title: '' }),
+      makeQuestion({ id: 'question-4', title: 'Saved question 4' })
+    ];
+
+    const zodErrors = {
+      'questions.1.question': 'Question text is required',
+      'questions.1.options.0.label': 'Option label is required'
+    };
+
+    const result = mapZodErrorsToQuestionErrors(zodErrors, questions);
+
+    expect(result).toEqual({
+      'question-3': {
+        title: 'Question text is required',
+        option: 'Option label is required'
+      }
+    });
+  });
+});

apps/dashboard/src/lib/features/course/components/exercise/store.ts

@@ -152,13 +152,17 @@ export function mapZodErrorsToQuestionErrors(
   questions: Question[]
 ): ExerciseEditorErrors {
   const errors: ExerciseEditorErrors = {};
+  const activeQuestions = questions.filter((question) => !question.deletedAt);
+
   for (const [path, message] of Object.entries(zodErrors)) {
     const pathParts = path.split('.');
     const questionIndex = pathParts[0] === 'questions' ? parseInt(pathParts[1]) : -1;
 
-    if (questionIndex >= 0 && questionIndex < questions.length) {
-      const question = questions[questionIndex];
-      if (question && !question.deletedAt) {
+    if (questionIndex >= 0 && questionIndex < activeQuestions.length) {
+      const activeQuestion = activeQuestions[questionIndex];
+      const question = questions.find((questionItem) => questionItem.id === activeQuestion.id);
+
+      if (question) {
         const qErrors = errors[question.id] || {};
 
         // Check if error is related to options