Prism/tests/Prism.Core.Tests/Commands/TestPurposeBindableBase.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Linq.Expressions;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;
using Prism.Mvvm;

namespace Prism.Tests.Commands
{
    /// <summary>
    /// Provides minimum functionality BindableBase based class in order to expose 
    /// GetPropertyChangedSubscribledLenght to test if PropertyObserve's 
    /// unsubscribing to PropertyChanged is working properly.
    /// </summary>
    public abstract class TestPurposeBindableBase : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        public int GetPropertyChangedSubscribledLenght()
        {
            return PropertyChanged?.GetInvocationList()?.Length ?? 0;
        }

        protected virtual bool SetProperty<T>(ref T storage, T value, [CallerMemberName] string propertyName = null)
        {
            if (Equals(storage, value)) return false;

            storage = value;
            RaisePropertyChanged(propertyName);

            return true;
        }

        protected void RaisePropertyChanged([CallerMemberName] string propertyName = null)
        {
            OnPropertyChanged(new PropertyChangedEventArgs(propertyName));
        }

        protected virtual void OnPropertyChanged(PropertyChangedEventArgs args)
        {
            PropertyChanged?.Invoke(this, args);
        }
    }
}