Password Manager and Tests

PasswordManager.cs

using System;
using System.Security.Cryptography;
using System.Text;

public class PasswordManager
{
    public string HashPassword(string password)
    {
        using (SHA256 sha256 = SHA256.Create())
        {
            byte[] hashedBytes = sha256.ComputeHash(Encoding.UTF8.GetBytes(password));
            return BitConverter.ToString(hashedBytes).Replace("-", "").ToLower();
        }
    }

    public bool VerifyPassword(string password, string hashedPassword)
    {
        string hashedInput = HashPassword(password);
        return hashedInput.Equals(hashedPassword);
    }
}

// Password Manager Tests

using Xunit;
using NSubstitute;

public class PasswordManagerTests
{
    [Fact]
    public void HashPassword_VerifyPassword_Correct()
    {
        // Arrange
        var passwordManager = new PasswordManager();
        var password = "MySecretPassword";

        // Act
        var hashedPassword = passwordManager.HashPassword(password);
        var result = passwordManager.VerifyPassword(password, hashedPassword);

        // Assert
        Assert.True(result);
    }

    [Fact]
    public void VerifyPassword_IncorrectPassword_ReturnsFalse()
    {
        // Arrange
        var passwordManager = new PasswordManager();
        var password = "MySecretPassword";
        var incorrectPassword = "IncorrectPassword";

        // Act
        var hashedPassword = passwordManager.HashPassword(password);
        var result = passwordManager.VerifyPassword(incorrectPassword, hashedPassword);

        // Assert
        Assert.False(result);
    }

    [Fact]
    public void VerifyPassword_UsingNSubstitute_Correct()
    {
        // Arrange
        var passwordManagerMock = Substitute.For<PasswordManager>();
        var password = "MySecretPassword";
        var hashedPassword = passwordManagerMock.HashPassword(password);

        // Act
        passwordManagerMock.VerifyPassword(password, hashedPassword).Returns(true);
        var result = passwordManagerMock.VerifyPassword(password, hashedPassword);

        // Assert
        Assert.True(result);
    }
}