fix: Bind With Trigger, add tests

src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net472.approved.txt

@@ -433,7 +433,7 @@ namespace ReactiveUI
     }
     public static class ObservableFuncMixins
     {
-        public static System.IObservable<TResult?> ToObservable<TSource, TResult>(this TSource? source, System.Linq.Expressions.Expression<System.Func<TSource, TResult?>> expression, bool beforeChange = false, bool skipInitial = false) { }
+        public static System.IObservable<TResult?> ToObservable<TSource, TResult>(this System.Linq.Expressions.Expression<System.Func<TSource, TResult?>> expression, TSource? source, bool beforeChange = false, bool skipInitial = false) { }
     }
     public static class ObservableLoggingMixin
     {

src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net5.0.approved.txt

@@ -428,7 +428,7 @@ namespace ReactiveUI
     }
     public static class ObservableFuncMixins
     {
-        public static System.IObservable<TResult?> ToObservable<TSource, TResult>(this TSource? source, System.Linq.Expressions.Expression<System.Func<TSource, TResult?>> expression, bool beforeChange = false, bool skipInitial = false) { }
+        public static System.IObservable<TResult?> ToObservable<TSource, TResult>(this System.Linq.Expressions.Expression<System.Func<TSource, TResult?>> expression, TSource? source, bool beforeChange = false, bool skipInitial = false) { }
     }
     public static class ObservableLoggingMixin
     {

src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.netcoreapp3.1.approved.txt

@@ -426,7 +426,7 @@ namespace ReactiveUI
     }
     public static class ObservableFuncMixins
     {
-        public static System.IObservable<TResult?> ToObservable<TSource, TResult>(this TSource? source, System.Linq.Expressions.Expression<System.Func<TSource, TResult?>> expression, bool beforeChange = false, bool skipInitial = false) { }
+        public static System.IObservable<TResult?> ToObservable<TSource, TResult>(this System.Linq.Expressions.Expression<System.Func<TSource, TResult?>> expression, TSource? source, bool beforeChange = false, bool skipInitial = false) { }
     }
     public static class ObservableLoggingMixin
     {

src/ReactiveUI.Tests/Mocks/PropertyBindViewModel.cs

@@ -8,6 +8,7 @@
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using System.Windows;
 using DynamicData.Binding;
 
 namespace ReactiveUI.Tests
@@ -18,14 +19,15 @@ namespace ReactiveUI.Tests
     /// <seealso cref="ReactiveUI.ReactiveObject" />
     public class PropertyBindViewModel : ReactiveObject
     {
-        private string? _Property1;
-        private PropertyBindModel? _Model;
-        private int _Property2;
-        private double _JustADouble;
-        private decimal _JustADecimal;
-        private double? _NullableDouble;
-        private int _JustAInt32;
-        private bool _JustABoolean;
+        private string? _property1;
+        private PropertyBindModel? _model;
+        private int _property2;
+        private double _justADouble;
+        private decimal _justADecimal;
+        private double? _nullableDouble;
+        private int _justAInt32;
+        private bool _justABoolean;
+        private Visibility _justAVisibility;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="PropertyBindViewModel"/> class.
@@ -42,26 +44,26 @@ public PropertyBindViewModel(PropertyBindModel? model = null)
         /// </summary>
         public string? Property1
         {
-            get => _Property1;
-            set => this.RaiseAndSetIfChanged(ref _Property1, value);
+            get => _property1;
+            set => this.RaiseAndSetIfChanged(ref _property1, value);
         }
 
         /// <summary>
         /// Gets or sets the property2.
         /// </summary>
         public int Property2
         {
-            get => _Property2;
-            set => this.RaiseAndSetIfChanged(ref _Property2, value);
+            get => _property2;
+            set => this.RaiseAndSetIfChanged(ref _property2, value);
         }
 
         /// <summary>
         /// Gets or sets the just a double.
         /// </summary>
         public double JustADouble
         {
-            get => _JustADouble;
-            set => this.RaiseAndSetIfChanged(ref _JustADouble, value);
+            get => _justADouble;
+            set => this.RaiseAndSetIfChanged(ref _justADouble, value);
         }
 
         /// <summary>
@@ -72,35 +74,41 @@ public double JustADouble
         /// </value>
         public bool JustABoolean
         {
-            get => _JustABoolean;
-            set => this.RaiseAndSetIfChanged(ref _JustABoolean, value);
+            get => _justABoolean;
+            set => this.RaiseAndSetIfChanged(ref _justABoolean, value);
         }
 
         /// <summary>
         /// Gets or sets the just a decimal.
         /// </summary>
         public decimal JustADecimal
         {
-            get => _JustADecimal;
-            set => this.RaiseAndSetIfChanged(ref _JustADecimal, value);
+            get => _justADecimal;
+            set => this.RaiseAndSetIfChanged(ref _justADecimal, value);
         }
 
         /// <summary>
         /// Gets or sets the just a int32.
         /// </summary>
         public int JustAInt32
         {
-            get => _JustAInt32;
-            set => this.RaiseAndSetIfChanged(ref _JustAInt32, value);
+            get => _justAInt32;
+            set => this.RaiseAndSetIfChanged(ref _justAInt32, value);
         }
 
         /// <summary>
         /// Gets or sets the nullable double.
         /// </summary>
         public double? NullableDouble
         {
-            get => _NullableDouble;
-            set => this.RaiseAndSetIfChanged(ref _NullableDouble, value);
+            get => _nullableDouble;
+            set => this.RaiseAndSetIfChanged(ref _nullableDouble, value);
+        }
+
+        public Visibility JustAVisibility
+        {
+            get => _justAVisibility;
+            set => this.RaiseAndSetIfChanged(ref _justAVisibility, value);
         }
 
         /// <summary>
@@ -116,8 +124,8 @@ public double? NullableDouble
         /// </summary>
         public PropertyBindModel? Model
         {
-            get => _Model;
-            set => this.RaiseAndSetIfChanged(ref _Model, value);
+            get => _model;
+            set => this.RaiseAndSetIfChanged(ref _model, value);
         }
     }
 }

src/ReactiveUI.Tests/Platforms/windows-xaml/PropertyBindingTest.cs

@@ -8,6 +8,9 @@
 using System.Globalization;
 using System.Linq;
 using System.Reactive;
+using System.Reactive.Disposables;
+using System.Reactive.Linq;
+using System.Reactive.Subjects;
 using DynamicData.Binding;
 using Xunit;
 
@@ -37,7 +40,7 @@ public void TwoWayBindWithFuncConvertersSmokeTest()
             vm.JustADecimal = 123.45m;
             Assert.NotEqual(vm.JustADecimal.ToString(CultureInfo.InvariantCulture), view.SomeTextBox.Text);
 
-            var disp = fixture.Bind(vm, view, x => x.JustADecimal, x => x.SomeTextBox.Text, (IObservable<Unit>?)null, d => d.ToString(), decimal.Parse);
+            var disp = fixture.Bind(vm, view, x => x.JustADecimal, x => x.SomeTextBox.Text, (IObservable<Unit>?)null, d => d.ToString(), t => decimal.TryParse(t, out var res) ? res : decimal.Zero);
 
             Assert.Equal(vm.JustADecimal.ToString(CultureInfo.InvariantCulture), view.SomeTextBox.Text);
             Assert.Equal(123.45m, vm.JustADecimal);
@@ -551,7 +554,21 @@ public void BindWithFuncShouldWorkAsExtensionMethodSmokeTest()
             PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
-            view.Bind(vm, x => x.JustADecimal, x => x.SomeTextBox.Text, d => d.ToString(CultureInfo.InvariantCulture), decimal.Parse);
+            vm.JustADecimal = 123.45m;
+            Assert.NotEqual(vm.JustADecimal.ToString(CultureInfo.InvariantCulture), view.SomeTextBox.Text);
+
+            view.Bind(vm, x => x.JustADecimal, x => x.SomeTextBox.Text, d => d.ToString(CultureInfo.InvariantCulture), t => decimal.TryParse(t, out var res) ? res : 0m);
+
+            Assert.Equal(view.SomeTextBox.Text, "123.45");
+
+            vm.JustADecimal = 1.0M;
+            Assert.Equal(view.SomeTextBox.Text, "1.0");
+
+            vm.JustADecimal = 2.0M;
+            Assert.Equal(view.SomeTextBox.Text, "2.0");
+
+            view.SomeTextBox.Text = "3.0";
+            Assert.Equal(vm.JustADecimal, 3.0M);
         }
 
         /// <summary>
@@ -578,5 +595,97 @@ public void BindInitialViewModelShouldBeGarbageCollectedWhenOverwritten()
 
             Assert.False(weakRef.IsAlive);
         }
+
+        [Fact]
+        public void OneWayBindWithHintTest()
+        {
+            CompositeDisposable dis = new();
+            PropertyBindViewModel? vm = new();
+            PropertyBindView view = new() { ViewModel = vm };
+            PropertyBinderImplementation fixture = new();
+
+            fixture.OneWayBind(vm, view, vm => vm.JustABoolean, v => v.SomeTextBox.Visibility, BooleanToVisibilityHint.Inverse).DisposeWith(dis);
+            Assert.Equal(view.SomeTextBox.Visibility, System.Windows.Visibility.Visible);
+
+            vm.JustABoolean = true;
+            Assert.Equal(view.SomeTextBox.Visibility, System.Windows.Visibility.Collapsed);
+
+            dis.Dispose();
+            Assert.True(dis.IsDisposed);
+        }
+
+        [Fact]
+        public void OneWayBindWithHintTestDisposeWithFailure()
+        {
+            CompositeDisposable? dis = null;
+            PropertyBindViewModel? vm = new();
+            PropertyBindView view = new() { ViewModel = vm };
+            PropertyBinderImplementation fixture = new();
+
+            Assert.Throws<ArgumentNullException>(() => fixture.OneWayBind(vm, view, vm => vm.JustABoolean, v => v.SomeTextBox.Visibility, BooleanToVisibilityHint.Inverse).DisposeWith(dis!));
+        }
+
+        [Fact]
+        public void BindToWithHintTest()
+        {
+            CompositeDisposable dis = new();
+            PropertyBindViewModel? vm = new();
+            var view = new PropertyBindView { ViewModel = vm };
+            var obs = vm.WhenAnyValue(x => x.JustABoolean);
+            var a = new PropertyBinderImplementation().BindTo(obs, view, v => v.SomeTextBox.Visibility, BooleanToVisibilityHint.Inverse).DisposeWith(dis);
+            Assert.Equal(view.SomeTextBox.Visibility, System.Windows.Visibility.Visible);
+
+            vm.JustABoolean = true;
+            Assert.Equal(view.SomeTextBox.Visibility, System.Windows.Visibility.Collapsed);
+
+            dis.Dispose();
+            Assert.True(dis.IsDisposed);
+        }
+
+        [Fact]
+        public void BindWithFuncToTriggerUpdateTest()
+        {
+            CompositeDisposable dis = new();
+            PropertyBindViewModel? vm = new();
+            var view = new PropertyBindView { ViewModel = vm };
+            var update = new Subject<bool>();
+
+            vm.JustADecimal = 123.45m;
+            Assert.NotEqual(vm.JustADecimal.ToString(CultureInfo.InvariantCulture), view.SomeTextBox.Text);
+
+            view.Bind(vm, x => x.JustADecimal, x => x.SomeTextBox.Text, update.AsObservable(), d => d.ToString(CultureInfo.InvariantCulture), t => decimal.TryParse(t, out var res) ? res : decimal.Zero).DisposeWith(dis);
+
+            vm.JustADecimal = 1.0M;
+
+            // value should have pre bind value
+            Assert.Equal(view.SomeTextBox.Text, "123.45");
+
+            // trigger UI update
+            update.OnNext(true);
+            Assert.Equal(view.SomeTextBox.Text, "1.0");
+
+            vm.JustADecimal = 2.0M;
+            Assert.Equal(view.SomeTextBox.Text, "1.0");
+
+            update.OnNext(true);
+            Assert.Equal(view.SomeTextBox.Text, "2.0");
+
+            // test reverse bind no trigger required
+            view.SomeTextBox.Text = "3.0";
+            Assert.Equal(vm.JustADecimal, 3.0M);
+
+            view.SomeTextBox.Text = "4.0";
+            Assert.Equal(vm.JustADecimal, 4.0M);
+
+            // test forward bind to ensure trigger is still honoured.
+            vm.JustADecimal = 2.0M;
+            Assert.Equal(view.SomeTextBox.Text, "4.0");
+
+            update.OnNext(true);
+            Assert.Equal(view.SomeTextBox.Text, "2.0");
+
+            dis.Dispose();
+            Assert.True(dis.IsDisposed);
+        }
     }
 }

src/ReactiveUI.Tests/Platforms/winforms/CommandBindingImplementationTests.cs

@@ -25,7 +25,7 @@ public void CommandBindByNameWireup()
             var fixture = new CommandBinderImplementation();
 
             var invokeCount = 0;
-            vm.Command1.Subscribe(_ => invokeCount += 1);
+            vm.Command1.Subscribe(_ => ++invokeCount);
 
             var disp = fixture.BindCommand(vm, view, x => x.Command1, x => x.Command1);
 
@@ -53,7 +53,7 @@ public void CommandBindToExplicitEventWireup()
             var fixture = new CommandBinderImplementation();
 
             var invokeCount = 0;
-            vm.Command2.Subscribe(_ => invokeCount += 1);
+            vm.Command2.Subscribe(_ => ++invokeCount);
 
             var disp = fixture.BindCommand(vm, view, x => x.Command2, x => x.Command2, "MouseUp");
 
@@ -64,5 +64,66 @@ public void CommandBindToExplicitEventWireup()
             view.Command2.RaiseMouseUpEvent(new MouseEventArgs(MouseButtons.Left, 1, 0, 0, 0));
             Assert.Equal(1, invokeCount);
         }
+
+        [Fact]
+        public void CommandBindByNameWireupWithParameter()
+        {
+            var vm = new WinformCommandBindViewModel();
+            var view = new WinformCommandBindView { ViewModel = vm };
+            ICommandBinderImplementation fixture = new CommandBinderImplementation();
+
+            var invokeCount = 0;
+            vm.Command3.Subscribe(_ => ++invokeCount);
+
+            var disp = CommandBinderImplementationMixins.BindCommand(fixture, vm, view, vm => vm.Command3, v => v.Command1, vm => vm.Parameter);
+
+            view.Command1.PerformClick();
+            Assert.Equal(1, invokeCount);
+            Assert.Equal(10, vm.ParameterResult);
+
+            // update the parameter to ensure its updated when the command is executed
+            vm.Parameter = 2;
+            view.Command1.PerformClick();
+            Assert.Equal(2, invokeCount);
+            Assert.Equal(20, vm.ParameterResult);
+
+            // break the Command3 subscription
+            var newCmd = ReactiveCommand.Create<int>(i => vm.ParameterResult = i * 2);
+            vm.Command3 = newCmd;
+
+            // ensure that the invoke count does not update and that the Command3 is now using the new math
+            view.Command1.PerformClick();
+            Assert.Equal(2, invokeCount);
+            Assert.Equal(4, vm.ParameterResult);
+
+            disp.Dispose();
+        }
+
+        [Fact]
+        public void CommandBindToExplicitEventWireupWithParameter()
+        {
+            var vm = new WinformCommandBindViewModel();
+            var view = new WinformCommandBindView { ViewModel = vm };
+            var fixture = new CommandBinderImplementation();
+
+            var invokeCount = 0;
+            vm.Command3.Subscribe(_ => ++invokeCount);
+
+            var disp = CommandBinderImplementationMixins.BindCommand(fixture, vm, view, x => x.Command3, x => x.Command2, vm => vm.Parameter, "MouseUp");
+
+            view.Command2.RaiseMouseUpEvent(new MouseEventArgs(MouseButtons.Left, 1, 0, 0, 0));
+            Assert.Equal(10, vm.ParameterResult);
+            Assert.Equal(1, invokeCount);
+
+            vm.Parameter = 2;
+            view.Command2.RaiseMouseUpEvent(new MouseEventArgs(MouseButtons.Left, 1, 0, 0, 0));
+            Assert.Equal(20, vm.ParameterResult);
+            Assert.Equal(2, invokeCount);
+
+            disp.Dispose();
+
+            view.Command2.RaiseMouseUpEvent(new MouseEventArgs(MouseButtons.Left, 1, 0, 0, 0));
+            Assert.Equal(2, invokeCount);
+        }
     }
 }