Ensure prisma client only instantiated once

prisma.ts

import { PrismaClient } from '@prisma/client';

declare global {
  interface CustomNodeJsGlobal extends NodeJS.Global {
    prisma: PrismaClient;
  }
}

const prisma: PrismaClient = global.prisma ?? new PrismaClient();

if (process.env.NODE_ENV === 'production') global.prisma = prisma;

export default prisma;