🧑‍💻 Explicit error message when MongoDB configuration lacking (#208)

src/lib/server/database.ts

@@ -6,6 +6,12 @@ import type { AbortedGeneration } from "$lib/types/AbortedGeneration";
 import type { Settings } from "$lib/types/Settings";
 import type { User } from "$lib/types/User";
 
+if (!MONGODB_URL) {
+	throw new Error(
+		"Please specify the MONGODB_URL environment variable inside .env.local. Set it to mongodb://localhost:27017 if you are running MongoDB locally, or to a MongoDB Atlas free instance for example."
+	);
+}
+
 const client = new MongoClient(MONGODB_URL, {
 	// directConnection: true
 });