jarv.is/lib/helpers/prisma.ts

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

// creating PrismaClient here prevents next.js from starting too many concurrent prisma instances and exhausting the
// number of connection pools available (especially when hot reloading from `next dev`).
// https://www.prisma.io/docs/guides/other/troubleshooting-orm/help-articles/nextjs-prisma-client-dev-practices

const prismaClientSingleton = () => {
  return new PrismaClient();
};

declare global {
  // eslint-disable-next-line no-var
  var prisma: undefined | ReturnType<typeof prismaClientSingleton>;
}

export const prisma = globalThis.prisma ?? prismaClientSingleton();

if (process.env.NODE_ENV !== "production") globalThis.prisma = prisma;