message: add test for SerialQueue::FirstSerial
diff: @@ -117,3 +117,25 @@ TEST(SerialQueue, ClearUpTo) {
  }
  ASSERT_TRUE(expectedValues.empty());
  }
  +
  +// Test FirstSerial
  +TEST(SerialQueue, FirstSerial) {
  + SerialQueue queue;
  +
  + std::vector<int> vector1 = {1, 2, 3, 4};
  + std::vector<int> vector2 = {5, 6, 7, 8};
  + std::vector<int> vector3 = {9, 0};
  +
  + queue.Enqueue(vector1, 0);
  + queue.Enqueue(std::move(vector2), 1);
  + queue.Enqueue(vector3, 2);
  +
  + EXPECT_EQ(queue.FirstSerial(), 0);
  +
  + queue.ClearUpTo(1);
  + EXPECT_EQ(queue.FirstSerial(), 2);
  +
  + queue.Clear();
  + queue.Enqueue(vector1, 6);
  + EXPECT_EQ(queue.FirstSerial(), 6);
  +}
  