c# - 如何为没有输入和输出的方法编写单元测试？

Question

我的项目是一个机器人电报。我有一个名为Mainclass的类。我想测试它的一个方法(SubmitNewsGetType)。这个方法没有输入和输出.此方法检查从用户收到的消息并发送合适的响应。这是我对类和方法的定义。

public class MainClass
{
    enum state : int
    {
        _firstState = 0,
        _submitNewsGetType = 1,
        _submitNewsGetNews = 11,
        _reservationGym = 2, 
        _reservationGymGetSans = 22, 
        _pollingForFood = 3, 
        _appointment = 4, 
        _cancelingReservation = 5, 
        _cancelingAppointment = 6, 
        Registeration = 7 
    };

    public TelegramBot bot;
    private  int stateBot;
    public Message sendMessage;
    private  string tempString;
    public  Message message;
    private  MessageTarget target;

    public void SubmitNewsGetType()
    {
        if (message.Text.Contains("/submitnews"))
        {
           sendMessage = bot.SendMessage(target, "Please select a type news: \n/Elmi\n/Farhangi\n/Honari\n/Amoozeshi\n/Varzeshi\n\n/Return");
        }
        else if (message.Text.Contains("/Elmi") ||
                 message.Text.Contains("/Farhangi") ||
                 message.Text.Contains("/Honari") ||
                 message.Text.Contains("/Amoozeshi") ||
                 message.Text.Contains("/Varzeshi"))
        {
           sendMessage = bot.SendMessage(target, "Please enter your news: \n\n/Return");

            stateBot = (int)state._submitNewsGetNews;
            tempString = message.Text;
        }
        else
        {
            bot.SendMessage(target, "Non definded! Please select a type news: \n/Elmi\n/Farhangi\n/Honari\n/Amoozeshi\n/Varzeshi\n\n/Return");
        }
    }

这是我的单元测试。我的问题是我无法初始化消息类型。

[TestMethod]
public void SubmitNewsGetNews_Test()
{
    MainClass instance = new MainClass();
    Message mess_output;

    //How to set value for a Message type??
    //This line get error
    Message mess_input="/submitnews"
    string expected="Please select a type news: \n/Elmi\n/Farhangi\n/Honari\n/Amoozeshi\n/Varzeshi\n\n/Return";

    if (mess_input is "/submitnews")
    {
        a.SubmitNewsGetType();
        mess_output= a.sendMessage;
        Assert.AreEqual(mess_output.Text,expected);
    } 
    else if (mess_input is "/elmi" or "/farhangi" or ...)
    else if ....
}

Answer 1

1. 创建涵盖TelegramBot 功能的接口(interface)并使TelegramBot 实现它。

interface ITelegramBot
{
    Message SendMessage(MessageTarget target, string msg);
}

1. 将 bot 成员的类型更改为 ITelegramBot

public ITelegramBot bot;

1. 创建 TelegramBot 的“假”类

class TelegramBotFake : ITelegramBot
{
    public Message ReturnMessage { get; set; }
    public string SendedMessage { get; set; }

    public Message SendMessage(MessageTarget target, string msg)
    {
        this.SendedMessage = msg;
        return this.ReturnMessage;
    }
}

1. 测试。尽量让任何逻辑操作远离测试方法。任何逻辑都可能包含错误，测试方法中的错误很难发现。
   为您的方法中的每个可能结果创建自己的测试 - 您将需要不止一个...

[TestMethod]
public void SubmitNewsGetNews_MessageContainsSubmitItems_SendPleaseSelectType()
{
    const string SUBMITITEMS = "/submitnews";
    TelegramBotFake fakebot = new TelegramBotFake();
    MainClass instance = new MainClass();
    instance.bot = fakebot; //Assign our fake bot
    instance.message.Text = SUBMITITEMS;
    string expected = "Please select a type news: \n/Elmi\n/Farhangi\n/Honari\n/Amoozeshi\n/Varzeshi\n\n/Return";

    instance.SubmitNewsGetType();

    //By checking faking bot.SendedMessage we sure that right method was executed
    Assert.AreEqual(instance.bot.SendedMessage, expected);
}