enforce-data-layer

Enforce Data Layer Separation

CRITICAL ARCHITECTURE RULE: This project follows strict data layer separation principles based on SOLID and encapsulation.

Architecture Rules (MUST FOLLOW)

1. Service Layer (/lib/services/)

• All Supabase queries MUST be defined here
• File naming: {table-name}.ts or {feature-name}-service.ts
• No Supabase client calls outside this layer
• Export pure functions that handle data operations
• ALL functions MUST have explicit return types defined
• ALL async functions MUST return Promise types

Type System Rules:

• Import types from /types/models.ts and /types/enums.ts - NEVER define types inline
• Reuse existing types whenever possible - Check /types/ before creating new types
• If new types are needed, define them in /types/ directory first
• Use Type Helpers: StudentRow, StudentInsert, StudentUpdate from /types/models.ts

Example structure:

// /lib/services/students.ts
import { createClient } from '@/lib/supabase/client'
import type { StudentRow, StudentInsert } from '@/types/models' // ✅ Import from centralized types

// ✅ CORRECT - Explicit return type with Promise<T>
export async function getStudents(centerId: number): Promise<StudentRow[]> {
  const supabase = createClient()
  const { data, error } = await supabase
    .from('students')
    .select('*')
    .eq('center_id', centerId)

  if (error) throw error
  return data
}

// ✅ CORRECT - Return type defined
export async function createStudent(studentData: StudentInsert): Promise<StudentRow> {
  const supabase = createClient()
  const { data, error } = await supabase
    .from('students')
    .insert(studentData)
    .select()
    .single()

  if (error) throw error
  return data
}

// ❌ WRONG - Missing return type
export async function deleteStudent(id: number) {
  // ...
}

// ❌ WRONG - Inline type definition
export async function updateStudent(id: number, data: { name: string }): Promise<any> {
  // Should import StudentUpdate from /types/models.ts
}