refactor: improve quiz retrieval logic with schedule validation

- Added validation to ensure 'scheduleId' is provided when retrieving quizzes, enhancing error handling.
- Implemented a check for the existence of the schedule before proceeding with quiz retrieval, improving robustness.
- Reformatted code for better readability and consistency in the Quiz schema.

src/Quiz/quiz.schema.ts

@@ -75,7 +75,7 @@ export class QuizSchema extends PothosSchema {
   quizAttempt() {
     return this.builder.prismaObject('QuizAttempt', {
       fields: (t) => ({
-        id: t.exposeID('id'),
+      id: t.exposeID('id'),
         quizId: t.exposeID('quizId'),
         quiz: t.relation('quiz'),
         userId: t.exposeID('userId'),
@@ -211,13 +211,22 @@ export class QuizSchema extends PothosSchema {
             if (!centerMentor) {
               throw new Error('Center mentor not found')
             }
-            return await this.prisma.quiz.findMany({
-              ...query,
-              where: {
-                serviceId: args.serviceId,
-                centerMentorId: centerMentor.mentorId,
-              },
-            })
+            if (args.scheduleId) {
+              const schedule = await this.prisma.schedule.findUnique({
+                where: { id: args.scheduleId },
+              })
+              if (!schedule) {
+                throw new Error('Schedule not found')
+              }
+              return await this.prisma.quiz.findMany({
+                ...query,
+                where: {
+                  serviceId: args.serviceId,
+                  centerMentorId: centerMentor.mentorId,
+                },
+              })
+            }
+            throw new Error('Schedule ID is required')
           }
         },
       }),