feat: simplify Prisma setup (#245)

app/db.server.ts

@@ -1,23 +1,9 @@
 import { PrismaClient } from "@prisma/client";
 
-let prisma: PrismaClient;
+import { singleton } from "./singleton.server";
 
-declare global {
-  var __db__: PrismaClient | undefined;
-}
-
-// This is needed because in development we don't want to restart
-// the server with every change, but we want to make sure we don't
-// create a new connection to the DB with every change either.
-// In production, we'll have a single connection to the DB.
-if (process.env.NODE_ENV === "production") {
-  prisma = new PrismaClient();
-} else {
-  if (!global.__db__) {
-    global.__db__ = new PrismaClient();
-  }
-  prisma = global.__db__;
-  prisma.$connect();
-}
+// Hard-code a unique key, so we can look up the client when this module gets re-imported
+const prisma = singleton("prisma", () => new PrismaClient());
+prisma.$connect();
 
 export { prisma };

app/singleton.server.ts

@@ -0,0 +1,13 @@
+// Since the dev server re-requires the bundle, do some shenanigans to make
+// certain things persist across that 😆
+// Borrowed/modified from https://github.com/jenseng/abuse-the-platform/blob/2993a7e846c95ace693ce61626fa072174c8d9c7/app/utils/singleton.ts
+
+export const singleton = <Value>(
+  name: string,
+  valueFactory: () => Value
+): Value => {
+  const g = global as any;
+  g.__singletons ??= {};
+  g.__singletons[name] ??= valueFactory();
+  return g.__singletons[name];
+};