public void ShouldSenderOrReceiverIdWorks() { // Arrange var conversationService = new ConversationService(agentService.Object, departmentService.Object, filterRepo.Object, filterExpressionFactory.Object, logRepo.Object); var rawConversations = new List <Conversation> { new Conversation { Id = 1, Subject = "Conversation Test 1", Messages = new List <Message> { new Message { SenderId = 1 } } }, new Conversation { Id = 2, Note = "Conversation2", Messages = new List <Message> { new Message { ReceiverId = 1 } } } }.AsQueryable(); // Act var conversations = conversationService.ApplySenderOrReceiverId(rawConversations, 1).DefaultIfEmpty().ToList(); // Assert Assert.Equal(2, conversations.Count()); }