public void FilterTextContainsTest() { //Arrange List <Message> messages = new List <Message>(); messages.Add(new Message("+3801", "+38 777", $"Message #1")); messages.Add(new Message("+3802", "+38 777", $"Message #2")); messages.Add(new Message("+3802", "+38 777", $"Message #22")); messages.Add(new Message("+3803", "+38 777", $"Message #4")); messages.Add(new Message("+3802", "+38 777", $"Message #5")); List <Message> expectedResult = new List <Message>(); expectedResult.Add(new Message("+3802", "+38 777", $"Message #2")); expectedResult.Add(new Message("+3802", "+38 777", $"Message #22")); //Act MessageFilter messageFilter = new MessageFilter(); List <Message> filteredMessages = messageFilter.TextContains(messages, "#2"); //Assert for (int i = 0; i < 2; i++) { Assert.AreEqual(expectedResult[i].Text, filteredMessages[i].Text); } }