ModelState is always valid in ASP.NET.CORE 2.2 Web Api

Question

I have an Asp.Net Core 2.2 web api project.Recently i tried to add validation on the models by adding DataAnnotation or the FluentValidation library.

In my Unit tests though i can see that even passing invalid model values the model state is valid.

StartUp.cs

services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2)
        .AddFluentValidation();

services.AddTransient<IValidator<ClientDto>, ClientValidator>();

ClientController

My Controller inherits from the ControllerBase and has the [ApiController] attribute.

    [HttpPost]
    public async Task<IActionResult> Create([FromBody] ClientDto client)
    {

        if (!ModelState.IsValid)
            return BadRequest();

        await _clientsService.Create(client);

        var clientAdded = await _clientsService.GetCustomer(c => c.IntegralFileName == client.IntegralFileName);

        return CreatedAtAction("Create", client, clientAdded);

    }

ClientDto.cs

 public class ClientDto
{
    public string Id { get; set; }

    public string FirstName { get; set; }

    public string LastName { get; set; }

    public bool Admin { get; set; }

    public bool Active { get; set; }
}

ClienValidator.cs

public class ClientValidator : AbstractValidator<ClientDto>
{
    public ClientValidator()
    {
        RuleFor(x => x.Id).NotNull();
        RuleFor(x => x.FirstName).Length(4, 20);
        RuleFor(x => x.LastName).Length(3, 20);
    }
}

I think i tried everything , some of them:

1)Removed Fluent Validation and replace it with DataAnnotations

2)Replace AddMcv with

   services.AddMvcCore()
            .SetCompatibilityVersion(CompatibilityVersion.Version_2_2)
            .AddJsonFormatters()
            .AddApiExplorer()
            .AddAuthorization()
            .AddDataAnnotations()
            .AddFluentValidation(fv => fv.RegisterValidatorsFromAssemblyContaining<ClientValidator>());

But i cant see any difference in the ModelState value. Any Ideas??

Thanks

Answer 1

Model state validation is not happening (or it's right to say that model binding does not happening) during unit-testing. This article describes some ways to implement what you want