Merge pull request #158 from michaelstonis/feature/nullable-property-…

…changed Updated property selectors to handle nullable types
Cysharp · Mar 6, 2024 · dee1eac · dee1eac
2 parents 646e94f + 423b2f5
commit dee1eac
Show file tree

Hide file tree

Showing 2 changed files with 265 additions and 10 deletions.
diff --git a/src/R3/Factories/ObserveProperty.cs b/src/R3/Factories/ObserveProperty.cs
@@ -27,7 +27,7 @@ public static Observable<TProperty> ObservePropertyChanged<T, TProperty>(this T
     /// `propertySelector1` and `propertySelector2` must be a Func specifying a simple property. For example, it extracts "Foo" from `x => x.Foo`.
     /// </summary>
     public static Observable<TProperty2> ObservePropertyChanged<T, TProperty1, TProperty2>(this T value,
-        Func<T, TProperty1> propertySelector1,
+        Func<T, TProperty1?> propertySelector1,
         Func<TProperty1, TProperty2> propertySelector2,
         bool pushCurrentValueOnSubscribe = true,
         CancellationToken cancellationToken = default,
@@ -42,7 +42,7 @@ public static Observable<TProperty2> ObservePropertyChanged<T, TProperty1, TProp
         var property1Name = propertySelector1Expr!.Substring(propertySelector1Expr.LastIndexOf('.') + 1);
         var property2Name = propertySelector2Expr!.Substring(propertySelector2Expr.LastIndexOf('.') + 1);
 
-        return new ObservePropertyChanged<T, TProperty1>(value, propertySelector1, property1Name, true, cancellationToken)
+        return new ObservePropertyChanged<T, TProperty1?>(value, propertySelector1, property1Name, true, cancellationToken)
             .Select(
                 (propertySelector2, property2Name, pushCurrentValueOnSubscribe, cancellationToken),
                 (firstPropertyValue, state) =>
@@ -59,8 +59,8 @@ firstPropertyValue is not null
     /// `propertySelector1`, `propertySelector2`, and `propertySelector3` must be a Func specifying a simple property. For example, it extracts "Foo" from `x => x.Foo`.
     /// </summary>
     public static Observable<TProperty3> ObservePropertyChanged<T, TProperty1, TProperty2, TProperty3>(this T value,
-        Func<T, TProperty1> propertySelector1,
-        Func<TProperty1, TProperty2> propertySelector2,
+        Func<T, TProperty1?> propertySelector1,
+        Func<TProperty1, TProperty2?> propertySelector2,
         Func<TProperty2, TProperty3> propertySelector3,
         bool pushCurrentValueOnSubscribe = true,
         CancellationToken cancellationToken = default,
@@ -79,12 +79,12 @@ public static Observable<TProperty3> ObservePropertyChanged<T, TProperty1, TProp
         var property2Name = propertySelector2Expr!.Substring(propertySelector2Expr.LastIndexOf('.') + 1);
         var property3Name = propertySelector3Expr!.Substring(propertySelector3Expr.LastIndexOf('.') + 1);
 
-        return new ObservePropertyChanged<T, TProperty1>(value, propertySelector1, property1Name, true, cancellationToken)
+        return new ObservePropertyChanged<T, TProperty1?>(value, propertySelector1, property1Name, true, cancellationToken)
             .Select(
                 (propertySelector2, property2Name, propertySelector3, property3Name, pushCurrentValueOnSubscribe, cancellationToken),
                 (firstPropertyValue, state) =>
                     firstPropertyValue is not null
-                        ? new ObservePropertyChanged<TProperty1, TProperty2>(firstPropertyValue, state.propertySelector2, state.property2Name, true, state.cancellationToken)
+                        ? new ObservePropertyChanged<TProperty1, TProperty2?>(firstPropertyValue, state.propertySelector2, state.property2Name, true, state.cancellationToken)
                             .Select(
                                 (state.propertySelector3, state.property3Name, pushCurrentValueOnSubscribe, cancellationToken),
                                 (secondPropertyValue, state2) =>
@@ -121,7 +121,7 @@ public static Observable<TProperty> ObservePropertyChanging<T, TProperty>(this T
     /// `propertySelector1` and `propertySelector2` must be a Func specifying a simple property. For example, it extracts "Foo" from `x => x.Foo`.
     /// </summary>
     public static Observable<TProperty2> ObservePropertyChanging<T, TProperty1, TProperty2>(this T value,
-        Func<T, TProperty1> propertySelector1,
+        Func<T, TProperty1?> propertySelector1,
         Func<TProperty1, TProperty2> propertySelector2,
         bool pushCurrentValueOnSubscribe = true,
         CancellationToken cancellationToken = default,
@@ -151,8 +151,8 @@ firstPropertyValue is not null
     /// `propertySelector1`, `propertySelector2`, and `propertySelector3` must be a Func specifying a simple property. For example, it extracts "Foo" from `x => x.Foo`.
     /// </summary>
     public static Observable<TProperty3> ObservePropertyChanging<T, TProperty1, TProperty2, TProperty3>(this T value,
-        Func<T, TProperty1> propertySelector1,
-        Func<TProperty1, TProperty2> propertySelector2,
+        Func<T, TProperty1?> propertySelector1,
+        Func<TProperty1, TProperty2?> propertySelector2,
         Func<TProperty2, TProperty3> propertySelector3,
         bool pushCurrentValueOnSubscribe = true,
         CancellationToken cancellationToken = default,

diff --git a/tests/R3.Tests/FactoryTests/ObservePropertyTest.cs b/tests/R3.Tests/FactoryTests/ObservePropertyTest.cs
@@ -1,4 +1,4 @@
-using System.ComponentModel;
+using System.ComponentModel;
 using System.Runtime.CompilerServices;
 
 namespace R3.Tests.FactoryTests;
@@ -21,6 +21,24 @@ public void PropertyChanged()
         liveList.AssertEqual([0, 1]);
     }
 
+    [Fact]
+    public void NullablePropertyChanged()
+    {
+        ChangesProperty propertyChanger = new();
+
+        using var liveList = propertyChanger
+            .ObservePropertyChanged(x => x.NullableInnerPropertyChanged)
+            .ToLiveList();
+
+        liveList.AssertEqual([null]);
+
+        var nipc = new ChangesProperty();
+
+        propertyChanger.NullableInnerPropertyChanged = nipc;
+
+        liveList.AssertEqual([null, nipc]);
+    }
+
     [Fact]
     public void NestedPropertyChanged()
     {
@@ -45,6 +63,52 @@ public void NestedPropertyChanged()
         liveList.AssertEqual([0, 1, 2]);
     }
 
+    [Fact]
+    public void NullableNestedPropertyChanged()
+    {
+        ChangesProperty propertyChanger = new();
+
+        using var liveList = propertyChanger
+            .ObservePropertyChanged(x => x.NullableInnerPropertyChanged, x => x.Value)
+            .ToLiveList();
+
+        liveList.AssertEqual([]);
+
+        propertyChanger.NullableInnerPropertyChanged = new();
+
+        liveList.AssertEqual([0]);
+
+        propertyChanger.NullableInnerPropertyChanged.Value = 1;
+
+        liveList.AssertEqual([0, 1]);
+
+        propertyChanger.NullableInnerPropertyChanged.Value = 2;
+
+        liveList.AssertEqual([0, 1, 2]);
+    }
+
+    [Fact]
+    public void NullableNestedPropertyChangedWithNullableEndProperty()
+    {
+        ChangesProperty propertyChanger = new();
+
+        using var liveList = propertyChanger
+            .ObservePropertyChanged(x => x.NullableInnerPropertyChanged, x => x.NullableInnerPropertyChanged)
+            .ToLiveList();
+
+        liveList.AssertEqual([]);
+
+        propertyChanger.NullableInnerPropertyChanged = new();
+
+        liveList.AssertEqual([null]);
+
+        var nipc = new ChangesProperty();
+
+        propertyChanger.NullableInnerPropertyChanged.NullableInnerPropertyChanged = nipc;
+
+        liveList.AssertEqual([null, nipc]);
+    }
+
     [Fact]
     public void DoubleNestedPropertyChanged()
     {
@@ -69,6 +133,55 @@ public void DoubleNestedPropertyChanged()
         liveList.AssertEqual([0, 1]);
     }
 
+    [Fact]
+    public void NullableDoubleNestedPropertyChanged()
+    {
+        ChangesProperty propertyChanger = new();
+
+        using var liveList = propertyChanger
+            .ObservePropertyChanged(x => x.NullableInnerPropertyChanged, x => x.NullableInnerPropertyChanged, x => x.Value)
+            .ToLiveList();
+
+        liveList.AssertEqual([]);
+
+        propertyChanger.NullableInnerPropertyChanged = new();
+
+        liveList.AssertEqual([]);
+
+        propertyChanger.NullableInnerPropertyChanged.NullableInnerPropertyChanged = new();
+
+        liveList.AssertEqual([0]);
+
+        propertyChanger.NullableInnerPropertyChanged.NullableInnerPropertyChanged.Value = 1;
+
+        liveList.AssertEqual([0, 1]);
+    }
+
+    [Fact]
+    public void NullableDoubleNestedPropertyChangedWithNullableEndProperty()
+    {
+        ChangesProperty propertyChanger = new();
+
+        using var liveList = propertyChanger
+            .ObservePropertyChanged(x => x.NullableInnerPropertyChanged, x => x.NullableInnerPropertyChanged, x => x.NullableInnerPropertyChanged)
+            .ToLiveList();
+
+        liveList.AssertEqual([]);
+
+        propertyChanger.NullableInnerPropertyChanged = new();
+
+        liveList.AssertEqual([]);
+
+        propertyChanger.NullableInnerPropertyChanged.NullableInnerPropertyChanged = new();
+
+        liveList.AssertEqual([null]);
+
+        var nipc = new ChangesProperty();
+        propertyChanger.NullableInnerPropertyChanged.NullableInnerPropertyChanged.NullableInnerPropertyChanged = nipc;
+
+        liveList.AssertEqual([null, nipc]);
+    }
+
     [Fact]
     public void PropertyChanging()
     {
@@ -85,6 +198,28 @@ public void PropertyChanging()
         liveList.AssertEqual([0, 0]);
     }
 
+    [Fact]
+    public void NullablePropertyChanging()
+    {
+        ChangesProperty propertyChanger = new();
+
+        using var liveList = propertyChanger
+            .ObservePropertyChanging(x => x.NullableInnerPropertyChanged)
+            .ToLiveList();
+
+        liveList.AssertEqual([null]);
+
+        var nipc1 = new ChangesProperty();
+        propertyChanger.NullableInnerPropertyChanged = nipc1;
+
+        liveList.AssertEqual([null, null]);
+
+        var nipc2 = new ChangesProperty();
+        propertyChanger.NullableInnerPropertyChanged = nipc2;
+
+        liveList.AssertEqual([null, null, nipc1]);
+    }
+
     [Fact]
     public void NestedPropertyChanging()
     {
@@ -109,6 +244,61 @@ public void NestedPropertyChanging()
         liveList.AssertEqual([0, 0, 1]);
     }
 
+    [Fact]
+    public void NullableNestedPropertyChanging()
+    {
+        ChangesProperty propertyChanger = new();
+
+        using var liveList = propertyChanger
+            .ObservePropertyChanging(x => x.NullableInnerPropertyChanged, x => x.Value)
+            .ToLiveList();
+
+        liveList.AssertEqual([]);
+
+        propertyChanger.NullableInnerPropertyChanged = new();
+
+        liveList.AssertEqual([0]);
+
+        propertyChanger.NullableInnerPropertyChanged.Value = 1;
+
+        liveList.AssertEqual([0, 0]);
+
+        propertyChanger.NullableInnerPropertyChanged.Value = 2;
+
+        liveList.AssertEqual([0, 0, 1]);
+    }
+
+    [Fact]
+    public void NullableNestedPropertyChangingWithNullableEndProperty()
+    {
+        ChangesProperty propertyChanger = new();
+
+        using var liveList = propertyChanger
+            .ObservePropertyChanging(x => x.NullableInnerPropertyChanged, x => x.NullableInnerPropertyChanged)
+            .ToLiveList();
+
+        liveList.AssertEqual([]);
+
+        propertyChanger.NullableInnerPropertyChanged = new();
+
+        liveList.AssertEqual([null]);
+
+        var nipc1 = new ChangesProperty();
+        propertyChanger.NullableInnerPropertyChanged.NullableInnerPropertyChanged = nipc1;
+
+        liveList.AssertEqual([null, null]);
+
+        var nipc2 = new ChangesProperty();
+        propertyChanger.NullableInnerPropertyChanged.NullableInnerPropertyChanged = nipc2;
+
+        liveList.AssertEqual([null, null, nipc1]);
+
+        var nipc3 = new ChangesProperty();
+        propertyChanger.NullableInnerPropertyChanged.NullableInnerPropertyChanged = nipc3;
+
+        liveList.AssertEqual([null, null, nipc1, nipc2]);
+    }
+
     [Fact]
     public void DoubleNestedPropertyChanging()
     {
@@ -137,10 +327,69 @@ public void DoubleNestedPropertyChanging()
         liveList.AssertEqual([0, 0, 1]);
     }
 
+    [Fact]
+    public void NullableDoubleNestedPropertyChanging()
+    {
+        ChangesProperty propertyChanger = new();
+
+        using var liveList = propertyChanger
+            .ObservePropertyChanging(x => x.NullableInnerPropertyChanged, x => x.NullableInnerPropertyChanged, x => x.Value)
+            .ToLiveList();
+
+        liveList.AssertEqual([]);
+
+        propertyChanger.NullableInnerPropertyChanged = new();
+
+        liveList.AssertEqual([]);
+
+        propertyChanger.NullableInnerPropertyChanged.NullableInnerPropertyChanged = new();
+
+        liveList.AssertEqual([0]);
+
+        propertyChanger.NullableInnerPropertyChanged.NullableInnerPropertyChanged.Value = 1;
+
+        liveList.AssertEqual([0, 0]);
+
+        propertyChanger.NullableInnerPropertyChanged.NullableInnerPropertyChanged.Value = 2;
+
+        liveList.AssertEqual([0, 0, 1]);
+    }
+
+    [Fact]
+    public void NullableDoubleNestedPropertyChangingWithNullableEndProperty()
+    {
+        ChangesProperty propertyChanger = new();
+
+        using var liveList = propertyChanger
+            .ObservePropertyChanging(x => x.NullableInnerPropertyChanged, x => x.NullableInnerPropertyChanged, x => x.NullableInnerPropertyChanged)
+            .ToLiveList();
+
+        liveList.AssertEqual([]);
+
+        propertyChanger.NullableInnerPropertyChanged = new();
+
+        liveList.AssertEqual([]);
+
+        propertyChanger.NullableInnerPropertyChanged.NullableInnerPropertyChanged = new();
+
+        liveList.AssertEqual([null]);
+
+        var nipc1 = new ChangesProperty();
+        propertyChanger.NullableInnerPropertyChanged.NullableInnerPropertyChanged.NullableInnerPropertyChanged = nipc1;
+
+        liveList.AssertEqual([null, null]);
+
+        var nipc2 = new ChangesProperty();
+        propertyChanger.NullableInnerPropertyChanged.NullableInnerPropertyChanged.NullableInnerPropertyChanged = nipc2;
+
+        liveList.AssertEqual([null, null, nipc1]);
+    }
+
     class ChangesProperty : INotifyPropertyChanged, INotifyPropertyChanging
     {
         private int _value;
         private ChangesProperty _innerPropertyChanged = default!;
+        private ChangesProperty? _nullableInnerPropertyChanged;
 
         public event PropertyChangedEventHandler? PropertyChanged;
         public event PropertyChangingEventHandler? PropertyChanging;
@@ -157,6 +406,12 @@ public ChangesProperty InnerPropertyChanged
             set => SetField(ref _innerPropertyChanged, value);
         }
 
+        public ChangesProperty? NullableInnerPropertyChanged
+        {
+            get => _nullableInnerPropertyChanged;
+            set => SetField(ref _nullableInnerPropertyChanged, value);
+        }
+
         private void OnPropertyChanged([CallerMemberName] string? propertyName = null)
         {
             PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));