public void ShouldDeliverErrorsWhenModelObservableValidationTriggers()
{
var viewModel = new IndeiTestViewModel();
const string namesShouldMatchMessage = "names should match.";
viewModel.ValidationRule(
vm => vm.OtherName,
viewModel.WhenAnyValue(
m => m.Name,
m => m.OtherName,
(name, other) => name == other),
namesShouldMatchMessage);
Assert.False(viewModel.HasErrors);
Assert.True(viewModel.ValidationContext.IsValid);
Assert.Single(viewModel.ValidationContext.Validations);
Assert.Empty(viewModel.GetErrors(nameof(viewModel.Name)).Cast <string>());
Assert.Empty(viewModel.GetErrors(nameof(viewModel.OtherName)).Cast <string>());
viewModel.Name = "JoJo";
viewModel.OtherName = "NoNo";
Assert.True(viewModel.HasErrors);
Assert.Empty(viewModel.GetErrors(nameof(viewModel.Name)).Cast <string>());
Assert.Single(viewModel.GetErrors(nameof(viewModel.OtherName)).Cast <string>());
Assert.Single(viewModel.ValidationContext.Text);
Assert.Equal(namesShouldMatchMessage, viewModel.ValidationContext.Text.Single());
}
public void ValidationRulesOfTheSamePropertyShouldNotDuplicate()
{
var viewModel = new IndeiTestViewModel();
viewModel.ValidationRule(
m => m.Name,
m => m is not null,
"Name shouldn't be null.");
viewModel.ValidationRule(
m => m.Name,
m => !string.IsNullOrWhiteSpace(m),
"Name shouldn't be white space.");
Assert.False(viewModel.ValidationContext.IsValid);
Assert.Equal(2, viewModel.ValidationContext.Validations.Count);
}
public void ShouldSendPropertyChangeNotificationsForCorrectProperties()
{
var viewModel = new IndeiTestViewModel();
viewModel.ValidationRule(
m => m.Name,
m => m is not null,
"Name shouldn't be null.");
viewModel.ValidationRule(
m => m.OtherName,
m => m is not null,
"Other name shouldn't be null.");
Assert.Single(viewModel.GetErrors(nameof(viewModel.Name)));
Assert.Single(viewModel.GetErrors(nameof(viewModel.OtherName)));
var arguments = new List <DataErrorsChangedEventArgs>();
viewModel.ErrorsChanged += (_, args) => arguments.Add(args);
viewModel.Name = "Josuke";
viewModel.OtherName = "Jotaro";
Assert.Equal(2, arguments.Count);
Assert.Equal(nameof(viewModel.Name), arguments[0].PropertyName);
Assert.Equal(nameof(viewModel.OtherName), arguments[1].PropertyName);
Assert.False(viewModel.HasErrors);
viewModel.Name = null;
viewModel.OtherName = null;
Assert.Equal(4, arguments.Count);
Assert.Equal(nameof(viewModel.Name), arguments[2].PropertyName);
Assert.Equal(nameof(viewModel.OtherName), arguments[3].PropertyName);
Assert.True(viewModel.HasErrors);
}