[Feature] Add value sanitizers to [ObservableProperty]

[sn4k3]

Overview

In many of my properties I must Clamp, Round, Max or Min the setter value. This auto defeats the [ObservableProperty] which make me implement the raw property. Example:

public double TimeoutSeconds
{
    get;
    set => SetProperty(ref field, Math.Round(
        Math.Clamp(value, 0, 10000),
        2,
        MidpointRounding.AwayFromZero)
    );
} = 5000;

Example of what I would like:

[ObservableProperty]
[ObservablePropertySetterClamp(0, 10000)]
[ObservablePropertySetterRound(2, MidpointRounding.AwayFromZero)]
public partial double TimeoutSeconds { get; set; }

API breakdown

Not sure how to make the API but I provide a sample of generated code:

[global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator", "8.4.0.0")]
[global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
public partial global::System.Double TimeoutSeconds
{
    get => field;
    set
    {
        // The new sanitizer magic here
        value = Math.Clamp(value, 0, 10000);
        value = Math.Round(value, 2, MidpointRounding.AwayFromZero);
        // End

        // Current implementation, unchanged.
        if (!global::System.Collections.Generic.EqualityComparer<global::System.Double>.Default.Equals(field, value))
        {
            OnLastExecutedDateTimeChanging(value);
            OnLastExecutedDateTimeChanging(default, value);
            field = value;
            OnLastExecutedDateTimeChanged(value);
            OnLastExecutedDateTimeChanged(default, value);
            OnPropertyChanged(global::CommunityToolkit.Mvvm.ComponentModel.__Internals.__KnownINotifyPropertyChangedArgs.LastExecutedDateTime);
        }
    }
}

Usage example

[ObservableProperty]
[ObservablePropertySetterClamp(0, 10000)]
[ObservablePropertySetterRound(2, MidpointRounding.AwayFromZero)]
public partial double TimeoutSeconds { get; set; }

[ObservableProperty]
[ObservablePropertySetterMin(0)]
public partial int LapCount { get; set; }

[ObservableProperty]
[ObservablePropertySetterStringTrim]
[ObservablePropertySetterStringUpperCase]
public partial string Country { get; set; }

[ObservableProperty]
[ObservablePropertySetterCustom(MyStaticSanitizerCallback)]
public partial string MySecretString { get; set; }

Breaking change?

No

Alternatives

The team can find a better way and/or names to do such, right now I don't see another alternative than using atributes.

Additional context

• Also implement other sanitizers useful to other uses and types
• If doing for setter we can also do for getter side?

Help us help you

Yes, I'd like to be assigned to work on this item

[bzd3y]

This is essentially, or could be, a duplicate of #1054. That issue would at least also solve this one.