proposal-system/api/tests/ProposalSystem.Tests/Validators/CustomerEmailValidatorTests.cs

using FluentAssertions;
using ProposalSystem.Application.DTOs;
using ProposalSystem.Application.Validators;
using Xunit;

namespace ProposalSystem.Tests.Validators;

/// <summary>
/// PR4: Tests for customer email format validation on both Create and Update DTOs.
/// Ensures the ContactEmail field, when provided, must be a valid email address.
/// </summary>
public class CustomerEmailValidatorTests
{
    private readonly CreateCustomerValidator _createValidator = new();
    private readonly UpdateCustomerValidator _updateValidator = new();

    #region CreateCustomerValidator — ContactEmail

    [Fact(DisplayName = "Create: null ContactEmail passes validation")]
    public void Create_NullEmail_Passes()
    {
        var request = new CreateCustomerRequest("Acme Corp", null, null);
        var result = _createValidator.Validate(request);
        result.IsValid.Should().BeTrue();
    }

    [Fact(DisplayName = "Create: valid ContactEmail passes validation")]
    public void Create_ValidEmail_Passes()
    {
        var request = new CreateCustomerRequest("Acme Corp", null, "john@example.com");
        var result = _createValidator.Validate(request);
        result.IsValid.Should().BeTrue();
    }

    [Theory(DisplayName = "Create: invalid ContactEmail fails validation")]
    [InlineData("not-an-email")]
    [InlineData("missing@")]
    [InlineData("@no-local.com")]
    public void Create_InvalidEmail_Fails(string email)
    {
        var request = new CreateCustomerRequest("Acme Corp", null, email);
        var result = _createValidator.Validate(request);
        result.IsValid.Should().BeFalse();
        result.Errors.Should().Contain(e => e.PropertyName == "ContactEmail");
    }

    [Fact(DisplayName = "Create: ContactEmail exceeding 320 chars fails")]
    public void Create_EmailTooLong_Fails()
    {
        var longEmail = new string('a', 310) + "@example.com"; // 322 chars
        var request = new CreateCustomerRequest("Acme Corp", null, longEmail);
        var result = _createValidator.Validate(request);
        result.IsValid.Should().BeFalse();
        result.Errors.Should().Contain(e => e.PropertyName == "ContactEmail");
    }

    #endregion

    #region UpdateCustomerValidator — ContactEmail

    [Fact(DisplayName = "Update: null ContactEmail passes validation")]
    public void Update_NullEmail_Passes()
    {
        var request = new UpdateCustomerRequest(null, null, null);
        var result = _updateValidator.Validate(request);
        result.IsValid.Should().BeTrue();
    }

    [Fact(DisplayName = "Update: valid ContactEmail passes validation")]
    public void Update_ValidEmail_Passes()
    {
        var request = new UpdateCustomerRequest(null, null, "john@example.com");
        var result = _updateValidator.Validate(request);
        result.IsValid.Should().BeTrue();
    }

    [Theory(DisplayName = "Update: invalid ContactEmail fails validation")]
    [InlineData("not-an-email")]
    [InlineData("missing@")]
    [InlineData("@no-local.com")]
    public void Update_InvalidEmail_Fails(string email)
    {
        var request = new UpdateCustomerRequest(null, null, email);
        var result = _updateValidator.Validate(request);
        result.IsValid.Should().BeFalse();
        result.Errors.Should().Contain(e => e.PropertyName == "ContactEmail");
    }

    [Fact(DisplayName = "Update: name exceeding 200 chars fails")]
    public void Update_NameTooLong_Fails()
    {
        var request = new UpdateCustomerRequest(new string('X', 201), null, null);
        var result = _updateValidator.Validate(request);
        result.IsValid.Should().BeFalse();
        result.Errors.Should().Contain(e => e.PropertyName == "Name");
    }

    #endregion
}