test: update test for multiplexed session

Author: alkatrivedi

test/multiplexed-session.ts

@@ -67,6 +67,7 @@ describe('MultiplexedSession', () => {
     return Object.assign(new Session(DATABASE, name), props, {
       create: sandbox.stub().resolves(),
       transaction: sandbox.stub().returns(new FakeTransaction()),
+      getMetadata: sandbox.stub().resolves({multiplexed: true}),
     });
   };
 
@@ -80,7 +81,6 @@ describe('MultiplexedSession', () => {
   });
 
   beforeEach(() => {
-    DATABASE.session = createSession;
     fakeMuxSession = createSession();
     sandbox
       .stub(DATABASE, 'createSession')
@@ -195,6 +195,15 @@ describe('MultiplexedSession', () => {
       const session = await multiplexedSession._acquire();
       assert.strictEqual(session, fakeMuxSession);
     });
+    it('should have the multiplexed property set to true', async () => {
+      sandbox.stub(multiplexedSession, '_getSession').resolves(fakeMuxSession);
+      const session = await multiplexedSession._acquire();
+      assert.strictEqual((await session!.getMetadata()).multiplexed, true);
+      assert.strictEqual(
+        (await fakeMuxSession!.getMetadata()).multiplexed,
+        true
+      );
+    });
   });
 
   describe('_getSession', () => {