graphql api tested & user resolver, schema and mongo interfaces tested

lib/mongodb.ts

@@ -1,7 +1,14 @@
-// lib/mongodb.ts
-import mongoose from 'mongoose';
+import mongoose from "mongoose";
 
-export const connectDB = async () => {
-    if (mongoose.connection.readyState >= 1) return;
-    await mongoose.connect(process.env.MONGO_URI!);
-};
+declare global { var mongoose: { conn: mongoose.Mongoose | null; promise: Promise<mongoose.Mongoose> | null } }
+let cached = global.mongoose;
+
+if (!cached) { cached = global.mongoose = { conn: null, promise: null } }
+
+export async function connectDB() {
+    if (cached.conn) return cached.conn;
+    if (!process.env.MONGODB_URI) { throw new Error("Please define MONGODB_URI in your environment variables") }
+    if (!cached.promise) { cached.promise = mongoose.connect(process.env.MONGODB_URI).then((mongoose) => mongoose) }
+    cached.conn = await cached.promise;
+    return cached.conn;
+}