clean-architecture-demo-user-manager/tests/UserManager.Application.Tests/Features/Users/CreateUserRequestDtoValidationUnitTests.cs

using FluentValidation.Results;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using UserManager.Application.Features.Users.Requests;

namespace UserManager.Application.UnitTests.Features.Users
{
    [TestClass]
    public class CreateUserRequestDtoValidationUnitTests
    {
        [TestMethod]
        public void CreateUserRequestDtoValidator_WhenFirstNameIsEmpty_ShouldReturnValidationError()
        {
            // Arrange
            CreateUserRequestDto request = new()
            {
                FirstName = string.Empty,
                LastName = "Doe"
            };

            // Act
            ValidationResult validationResult = new CreateUserRequestDtoValidator().Validate(request);

            // Assert
            Assert.IsFalse(validationResult.IsValid);
            Assert.AreEqual("FirstName is required.", validationResult.Errors[0].ErrorMessage);
        }

        [TestMethod]
        public void CreateUserRequestDtoValidator_WhenLastNameIsEmpty_ShouldReturnValidationError()
        {
            // Arrange
            CreateUserRequestDto request = new()
            {
                FirstName = "John",
                LastName = string.Empty
            };

            // Act
            ValidationResult validationResult = new CreateUserRequestDtoValidator().Validate(request);

            // Assert
            Assert.IsFalse(validationResult.IsValid);
            Assert.AreEqual("LastName is required.", validationResult.Errors[0].ErrorMessage);
        }
    }
}