준비하면 updateRoomUser가 수신되는지에 관한 테스트 추가

@@ -23,10 +23,28 @@ describe("준비", () => {
     } = prepareJoinedRoom(1, 2, true);
 
     expect(room.isReady(user)).eq(false);
+
     socket.testOk("ready", { ready: true });
     expect(room.isReady(user)).eq(true);
+    expect(socket.socket.received("updateRoomUser")).deep.eq({
+      state: "updated",
+      user: {
+        username: user.username,
+        admin: false,
+        ready: true,
+      },
+    });
+
     socket.testOk("ready", { ready: false });
     expect(room.isReady(user)).eq(false);
+    expect(socket.socket.received("updateRoomUser")).deep.eq({
+      state: "updated",
+      user: {
+        username: user.username,
+        admin: false,
+        ready: false,
+      },
+    });
   });
   it("방장은 준비할 수 없습니다", () => {
     const {