ASP.NET Core 2.2 is not firing Validate method in IValidatableObject - asp.net-mvc

Question

I am trying to do some custom validation but I cannot seem to get the validation method to fire. Please let me know what I might be missing. Thanks!
Following is my code:
Model:
public class TestModel : IValidatableObject
{
[Required]
public string FirstName { get; set; }
[Required]
public string LastName { get; set; }
public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
{
if (FirstName == "Hello")
yield return ValidationResult.Success;
else
yield return new ValidationResult("Error from Validate method");
}
}
View:
#model EswSigningServer.Models.TestModel
#{
ViewData["Title"] = "Test";
}
<h2>Test</h2>
<h4>TestModel</h4>
<hr />
<div class="row">
<div class="col-md-4">
<form asp-action="Test">
<div asp-validation-summary="ModelOnly" class="text-danger"></div>
<div class="form-group">
<label asp-for="FirstName" class="control-label"></label>
<input asp-for="FirstName" class="form-control" />
<span asp-validation-for="FirstName" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="LastName" class="control-label"></label>
<input asp-for="LastName" class="form-control" />
<span asp-validation-for="LastName" class="text-danger"></span>
</div>
<div class="form-group">
<input type="submit" value="Test" class="btn btn-default" />
</div>
</form>
</div>
</div>
<div>
<a asp-action="Index">Back to List</a>
</div>
#section Scripts {
#{await Html.RenderPartialAsync("_ValidationScriptsPartial");}
}
Controller:
public ActionResult Test()
{
TestModel createKey = new TestModel();
return View(createKey);
}
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Test(IFormCollection collection)
{
try
{
if (ModelState.IsValid)
{
// TODO: Add insert logic here
return RedirectToAction(nameof(Index));
}
else
{
return View();
}
}
catch
{
return View();
}
}
I've also tried adding the validator to a single attribute using the following method and that doesn't fire either:
public class MyValidator : ValidationAttribute
{
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
return new ValidationResult("Hello");
}
}

Answer 1

IValidatableObject is a class-level validation. When model binding , it will call the Validate method determines whether the specified object is valid .If you want to get the validation method to fire , you should change the parameter type of Test method to TestModel as shown:
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Test(TestModel model)