build fixes

src/lib/mongodb.ts

@@ -1,23 +1,42 @@
 import { MongoClient } from "mongodb";
 
-const uri = process.env.MONGODB_URI!;
-const options = {};
+/**
+ * Lazy MongoClient promise. We don't touch `process.env.MONGODB_URI` at module
+ * import time so `next build` / page-data collection doesn't crash when the env
+ * isn't populated (e.g. inside a Docker build with no runtime env).
+ */
 
-let client: MongoClient;
-let clientPromise: Promise<MongoClient>;
-
-if (process.env.NODE_ENV === "development") {
-  const globalWithMongo = global as typeof globalThis & {
-    _mongoClientPromise?: Promise<MongoClient>;
-  };
-  if (!globalWithMongo._mongoClientPromise) {
-    client = new MongoClient(uri, options);
-    globalWithMongo._mongoClientPromise = client.connect();
-  }
-  clientPromise = globalWithMongo._mongoClientPromise;
-} else {
-  client = new MongoClient(uri, options);
-  clientPromise = client.connect();
+declare global {
+  var _mongoClientPromise: Promise<MongoClient> | undefined;
 }
 
+function createClientPromise(): Promise<MongoClient> {
+  const uri = process.env.MONGODB_URI;
+  if (!uri) {
+    throw new Error("MONGODB_URI is not set");
+  }
+  const client = new MongoClient(uri, {});
+  return client.connect();
+}
+
+function getClientPromise(): Promise<MongoClient> {
+  if (process.env.NODE_ENV === "development") {
+    if (!globalThis._mongoClientPromise) {
+      globalThis._mongoClientPromise = createClientPromise();
+    }
+    return globalThis._mongoClientPromise;
+  }
+  if (!globalThis._mongoClientPromise) {
+    globalThis._mongoClientPromise = createClientPromise();
+  }
+  return globalThis._mongoClientPromise;
+}
+
+const clientPromise: Promise<MongoClient> = {
+  then: (onFulfilled, onRejected) => getClientPromise().then(onFulfilled, onRejected),
+  catch: (onRejected) => getClientPromise().catch(onRejected),
+  finally: (onFinally) => getClientPromise().finally(onFinally),
+  [Symbol.toStringTag]: "Promise",
+} as Promise<MongoClient>;
+
 export default clientPromise;