Challenge — tRPC Task Manager

Objective

Build a full-stack Task Manager using Next.js 15 + tRPC + Prisma with end-to-end type safety.

Requirements

tRPC Router (40 points)

Create the following procedures:

tasks router:

• list — protected query, returns tasks for current user
• byId — protected query, input: { id: string }
• create — protected mutation, input: title, description?, priority?, dueDate?
• update — protected mutation, input: id + partial task fields
• delete — protected mutation, input: { id: string }
• complete — protected mutation, input: { id: string } — toggles completed

projects router:

• list — protected query
• create — protected mutation
• tasksFor — protected query, input: { projectId: string }

React Client (40 points)

• Task list using trpc.tasks.list.useQuery()
• Create task form using trpc.tasks.create.useMutation()
• Check/uncheck task with optimistic update
• Delete task with confirmation (optimistic update)
• Filter tasks by project using query input

Quality (20 points)

• All inputs validated with Zod (min/max lengths, valid dates, etc.)
• TRPCError thrown for unauthorized access / not found
• TypeScript: no any
• Loading and error states on all queries/mutations

Grading

Criteria	Points
tRPC server setup (router, context, auth)	15
All task procedures implemented	20
Project procedures	10
React query hooks working	15
Optimistic updates on complete/delete	15
Zod validation on all inputs	10
Error handling (401, 404)	10
TypeScript quality	5
Total	100

Schema

model Task {
  id          String    @id @default(cuid())
  title       String
  description String?
  completed   Boolean   @default(false)
  priority    Priority  @default(MEDIUM)
  dueDate     DateTime?
  userId      String
  user        User      @relation(fields: [userId], references: [id])
  projectId   String?
  project     Project?  @relation(fields: [projectId], references: [id])
  createdAt   DateTime  @default(now())
  updatedAt   DateTime  @updatedAt
}

model Project {
  id        String   @id @default(cuid())
  name      String
  userId    String
  user      User     @relation(fields: [userId], references: [id])
  tasks     Task[]
  createdAt DateTime @default(now())
}

enum Priority { LOW MEDIUM HIGH }

Bonus

• Drag-and-drop task reordering (update a position field)
• tRPC subscriptions for real-time task updates (WebSocket)
• Generate a REST API from tRPC using trpc-openapi
• E2E tests with Playwright