🔧 fix: Add support for configurable MongoDB database name in connection logic

api/db/connect.spec.js

@@ -0,0 +1,102 @@
+jest.mock('dotenv');
+require('dotenv').config();
+const mongoose = require('mongoose');
+const { MongoMemoryServer } = require('mongodb-memory-server');
+
+// Helper to clear the connect module from require cache
+function clearConnectModule() {
+  delete require.cache[require.resolve('./connect')];
+}
+
+beforeEach(() => {
+  // Reset environment and global state
+  clearConnectModule();
+  delete process.env.MONGO_URI;
+  delete process.env.MONGO_DB_NAME;
+  global.mongoose = undefined;
+});
+
+describe('connectDb Module', () => {
+  it('throws if MONGO_URI is not defined', () => {
+    expect(() => require('./connect')).toThrow('Please define the MONGO_URI environment variable');
+  });
+
+  describe('with in-memory MongoDB', () => {
+    let mongoServer;
+    let uri;
+
+    beforeAll(async () => {
+      mongoServer = await MongoMemoryServer.create();
+      uri = mongoServer.getUri();
+    });
+
+    afterAll(async () => {
+      // Ensure real mongoose connection is torn down
+      await mongoose.disconnect();
+      await mongoServer.stop();
+    });
+
+    it('connects using only MONGO_URI (no dbName override)', async () => {
+      process.env.MONGO_URI = uri;
+      clearConnectModule();
+      const { connectDb } = require('./connect');
+
+      const mongooseInstance = await connectDb();
+      expect(mongooseInstance).toBe(mongoose);
+
+      // The default DB is whatever follows the last slash in the URI
+      const defaultDbNameMatch = uri.match(/\/([\w-]+)(\?.*)?$/);
+      const defaultDbName = defaultDbNameMatch ? defaultDbNameMatch[1] : mongoose.connection.name;
+      expect(mongooseInstance.connection.name).toBe(defaultDbName);
+    });
+
+    it('strips any DB name in URI when MONGO_DB_NAME is set', async () => {
+      process.env.MONGO_URI = uri;
+      process.env.MONGO_DB_NAME = 'ignoredDbName';
+      clearConnectModule();
+
+      const connectSpy = jest.spyOn(mongoose, 'connect');
+      const { connectDb } = require('./connect');
+      await connectDb();
+
+      const [calledUri, calledOpts] = connectSpy.mock.calls[0];
+      // Should have removed the trailing "/<dbname>"
+      expect(calledUri).not.toMatch(/\/[\w-]+$/);
+      // And since we strip it rather than passing dbName, opts.dbName remains unset
+      expect(calledOpts).not.toHaveProperty('dbName');
+
+      connectSpy.mockRestore();
+    });
+
+    it('caches the connection between calls', async () => {
+      process.env.MONGO_URI = uri;
+      clearConnectModule();
+      const { connectDb } = require('./connect');
+
+      const first = await connectDb();
+      // simulate still-connected
+      mongoose.connection.readyState = 1;
+      const second = await connectDb();
+
+      expect(second).toBe(first);
+    });
+
+    it('reconnects if cached conn is disconnected', async () => {
+      process.env.MONGO_URI = uri;
+      clearConnectModule();
+      const { connectDb } = require('./connect');
+
+      // First, establish a connection
+      await connectDb();
+      expect(mongoose.connection.readyState).toBe(1);
+
+      // Now actually tear it down
+      await mongoose.disconnect();
+      expect(mongoose.connection.readyState).toBe(0);
+
+      // Calling again should reconnect
+      await connectDb();
+      expect(mongoose.connection.readyState).toBe(1);
+    });
+  });
+});