Merging multiple ReactiveProperties into a single output signal when any one of them changes

UniRx_MergePropertyTest.cs

    [Test]
    public void MergePropertyTest() {
        // Create an IEnumerable list of reactive proeprties
        List<ReactiveProperty<int>> rxPropertyList = new List<ReactiveProperty<int>>();

        // Add a couple reactive properties
        rxPropertyList.Add(new ReactiveProperty<int>(1));
        rxPropertyList.Add(new ReactiveProperty<int>(2));

        // Convert the IEnumerable list to an observable stream
        IObservable<ReactiveProperty<int>> rxPropertyStream = rxPropertyList.ToObservable();

        // Merge all the ReactiveProperty streams together (but only observe changes)
        IObservable<int> rxPropertyChangedStream = rxPropertyStream.SelectMany(rxProperty=> rxProperty.DistinctUntilChanged() );

        // Convert to a simple signal (Unit)
        IObservable<Unit> anyChangedStream = rxPropertyChangedStream.Select(xs => Unit.Default);

        var recordStreamOutput = new List<string>();
        anyChangedStream.Materialize().Subscribe(xs => recordStreamOutput.Add(xs.ToString()));

        // Check (each reactive property sends its first value)
        recordStreamOutput.IsCollection("OnNext(())", "OnNext(())");

        // Do
        rxPropertyList[0].Value = 3;

        // Check
        recordStreamOutput.IsCollection("OnNext(())", "OnNext(())", "OnNext(())" );

        // Do
        rxPropertyList[1].Value = 4;
        rxPropertyList[1].Value = 5;
        rxPropertyList[1].Value = 5; // Ignored by DistintUntilChanged
        rxPropertyList[1].Value = 5; // Ignored by DistintUntilChanged
        rxPropertyList[1].Value = 5; // Ignored by DistintUntilChanged

        // Check
        recordStreamOutput.IsCollection("OnNext(())", "OnNext(())", "OnNext(())", "OnNext(())", "OnNext(())");
    }