C# における一般的なテスト フレームワークと単体テストの問題

[TestFixture]
public class CalculatorTest
{
    private Calculator _calculator;

    [SetUp]
    public void Setup()
    {
        _calculator = new Calculator();
    }

    [Test]
    public void AddTest()
    {
        int result = _calculator.Add(2, 3);
        Assert.AreEqual(5, result);
    }

    [Test]
    public void SubtractTest()
    {
        int result = _calculator.Subtract(5, 3);
        Assert.AreEqual(2, result);
    }
}

public class CalculatorTest
{
    private Calculator _calculator;

    public CalculatorTest()
    {
        _calculator = new Calculator();
    }

    [Fact]
    public void AddTest()
    {
        int result = _calculator.Add(2, 3);
        Assert.Equal(5, result);
    }

    [Fact]
    public void SubtractTest()
    {
        int result = _calculator.Subtract(5, 3);
        Assert.Equal(2, result);
    }
}

public interface IEmailSender
{
    void SendEmail(string to, string subject, string body);
}

public class EmailService
{
    private IEmailSender _emailSender;

    public EmailService(IEmailSender emailSender)
    {
        _emailSender = emailSender;
    }

    public void SendWelcomeEmail(string to)
    {
        _emailSender.SendEmail(to, "Welcome", "Welcome to our website!");
    }
}

[Test]
public void SendWelcomeEmailTest()
{
    var emailSenderMock = new Mock<IEmailSender>();
    var emailService = new EmailService(emailSenderMock.Object);

    emailService.SendWelcomeEmail("test@example.com");

    emailSenderMock.Verify(
        x => x.SendEmail(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()), 
        Times.Once);
}

public class FileReader
{
    public virtual string ReadFile(string filePath)
    {
        // 读取文件的逻辑
    }
}

public class DataProcessor
{
    private FileReader _fileReader;

    public DataProcessor(FileReader fileReader)
    {
        _fileReader = fileReader;
    }

    public string ProcessData(string filePath)
    {
        string fileContent = _fileReader.ReadFile(filePath);
        // 处理数据的逻辑
        return result;
    }
}

[Test]
public void ProcessDataTest()
{
    var fileReaderStub = new Mock<FileReader>();
    fileReaderStub.Setup(x => x.ReadFile(It.IsAny<string>()))
        .Returns("Test data");

    var dataProcessor = new DataProcessor(fileReaderStub.Object);
    string result = dataProcessor.ProcessData("test.txt");

    Assert.AreEqual("Processed data", result);
}