Feature: Add Test Sequencer (#3587)

src/ReactiveUI.Fody.Analyzer.Test/ReactiveObjectAnalyzerTest.cs

@@ -32,7 +32,7 @@ public void CheckEmptyFileReturnsNoFailures()
         [Fact]
         public void ShouldGiveAnErrorWhenClassDoesNotImplement()
         {
-            var test = @"
+            const string test = @"
     using System;
     using System.Collections.Generic;
     using System.Linq;
@@ -68,7 +68,7 @@ public class TypeName
         [Fact]
         public void ShouldNotGiveAnErrorWhenClassInherits()
         {
-            var test = @"
+            const string test = @"
     using System;
     using System.Collections.Generic;
     using System.Linq;
@@ -95,7 +95,7 @@ public class TypeName : ReactiveObject
         [Fact]
         public void ShouldNotGiveAnErrorWhenClassImplements()
         {
-            var test = @"
+            const string test = @"
     using System;
     using System.Collections.Generic;
     using System.Linq;
@@ -122,7 +122,7 @@ public class TypeName : IReactiveObject
         [Fact]
         public void ShouldGiveErrorForNonAutoProperty()
         {
-            var test = @"
+            const string test = @"
     using System;
     using System.Collections.Generic;
     using System.Linq;

src/ReactiveUI.Testing.Tests/TestFixture.cs

@@ -30,7 +30,6 @@ public class TestFixture
         /// <summary>
         /// Gets or sets the variables.
         /// </summary>
-        [SuppressMessage("Design", "CA2227: Read only dictionary", Justification = "Used in mock.")]
         public Dictionary<string, string>? Variables { get; set; }
     }
 }

src/ReactiveUI.Testing.Tests/TestSequencerTests.cs

@@ -0,0 +1,42 @@
+// Copyright (c) 2023 .NET Foundation and Contributors. All rights reserved.
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for full license information.
+
+using Xunit;
+
+namespace ReactiveUI.Testing.Tests
+{
+    /// <summary>
+    /// TestSequencerTests.
+    /// </summary>
+    public class TestSequencerTests
+    {
+        /// <summary>
+        /// Shoulds the execute tests in order.
+        /// </summary>
+        /// <returns>A <see cref="Task"/> representing the asynchronous unit test.</returns>
+        [Fact]
+        public async Task Should_Execute_Tests_In_Order()
+        {
+            using var testSequencer = new TestSequencer();
+            var subject = new Subject<Unit>();
+            subject.Subscribe(async _ => await testSequencer.AdvancePhaseAsync());
+
+            Assert.Equal(0, testSequencer.CurrentPhase);
+            Assert.Equal(0, testSequencer.CompletedPhases);
+            subject.OnNext(Unit.Default);
+            Assert.Equal(1, testSequencer.CurrentPhase);
+            Assert.Equal(0, testSequencer.CompletedPhases);
+            await testSequencer.AdvancePhaseAsync("Phase 1");
+            Assert.Equal(1, testSequencer.CurrentPhase);
+            Assert.Equal(1, testSequencer.CompletedPhases);
+            subject.OnNext(Unit.Default);
+            Assert.Equal(2, testSequencer.CurrentPhase);
+            Assert.Equal(1, testSequencer.CompletedPhases);
+            await testSequencer.AdvancePhaseAsync("Phase 2");
+            Assert.Equal(2, testSequencer.CurrentPhase);
+            Assert.Equal(2, testSequencer.CompletedPhases);
+        }
+    }
+}

src/ReactiveUI.Testing/TestSequencer.cs

@@ -0,0 +1,84 @@
+// Copyright (c) 2023 .NET Foundation and Contributors. All rights reserved.
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for full license information.
+
+namespace ReactiveUI.Testing
+{
+    /// <summary>
+    /// Test Sequencer.
+    /// </summary>
+    /// <seealso cref="System.IDisposable" />
+    public class TestSequencer : IDisposable
+    {
+        private readonly Barrier _phaseSync;
+        private bool _disposedValue;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TestSequencer"/> class.
+        /// </summary>
+        public TestSequencer() => _phaseSync = new(2);
+
+        /// <summary>
+        /// Gets the number of completed phases.
+        /// </summary>
+        /// <value>
+        /// The completed phases.
+        /// </value>
+        public long CompletedPhases => _phaseSync.CurrentPhaseNumber;
+
+        /// <summary>
+        /// Gets the current phase.
+        /// </summary>
+        /// <value>
+        /// The current phase.
+        /// </value>
+        public long CurrentPhase { get; private set; }
+
+        /// <summary>
+        /// Advances this phase instance.
+        /// </summary>
+        /// <param name="comment">The comment for Test visual identification Purposes only.</param>
+        /// <returns>
+        /// A <see cref="Task" /> representing the asynchronous operation.
+        /// </returns>
+#pragma warning disable RCS1163 // Unused parameter.
+        public Task AdvancePhaseAsync(string comment = "")
+#pragma warning restore RCS1163 // Unused parameter.
+        {
+            if (_phaseSync.ParticipantCount == _phaseSync.ParticipantsRemaining)
+            {
+                CurrentPhase = CompletedPhases + 1;
+            }
+
+            return Task.Run(() => _phaseSync?.SignalAndWait(CancellationToken.None));
+        }
+
+        /// <summary>
+        /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
+        /// </summary>
+        public void Dispose()
+        {
+            // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
+            Dispose(disposing: true);
+            GC.SuppressFinalize(this);
+        }
+
+        /// <summary>
+        /// Releases unmanaged and - optionally - managed resources.
+        /// </summary>
+        /// <param name="disposing"><c>true</c> to release both managed and unmanaged resources; <c>false</c> to release only unmanaged resources.</param>
+        protected virtual void Dispose(bool disposing)
+        {
+            if (!_disposedValue)
+            {
+                if (disposing)
+                {
+                    _phaseSync.Dispose();
+                }
+
+                _disposedValue = true;
+            }
+        }
+    }
+}

src/ReactiveUI.Tests/API/ApiApprovalTests.Testing.DotNet6_0.verified.txt

@@ -43,4 +43,13 @@ namespace ReactiveUI.Testing
             where T : System.Reactive.Concurrency.IScheduler { }
         public static System.IDisposable WithScheduler(System.Reactive.Concurrency.IScheduler scheduler) { }
     }
+    public class TestSequencer : System.IDisposable
+    {
+        public TestSequencer() { }
+        public long CompletedPhases { get; }
+        public long CurrentPhase { get; }
+        public System.Threading.Tasks.Task AdvancePhaseAsync(string comment = "") { }
+        public void Dispose() { }
+        protected virtual void Dispose(bool disposing) { }
+    }
 }

src/ReactiveUI.Tests/API/ApiApprovalTests.Testing.DotNet7_0.verified.txt

@@ -43,4 +43,13 @@ namespace ReactiveUI.Testing
             where T : System.Reactive.Concurrency.IScheduler { }
         public static System.IDisposable WithScheduler(System.Reactive.Concurrency.IScheduler scheduler) { }
     }
+    public class TestSequencer : System.IDisposable
+    {
+        public TestSequencer() { }
+        public long CompletedPhases { get; }
+        public long CurrentPhase { get; }
+        public System.Threading.Tasks.Task AdvancePhaseAsync(string comment = "") { }
+        public void Dispose() { }
+        protected virtual void Dispose(bool disposing) { }
+    }
 }

src/ReactiveUI.Tests/API/ApiApprovalTests.Testing.Net4_7.verified.txt

@@ -43,4 +43,13 @@ namespace ReactiveUI.Testing
             where T : System.Reactive.Concurrency.IScheduler { }
         public static System.IDisposable WithScheduler(System.Reactive.Concurrency.IScheduler scheduler) { }
     }
+    public class TestSequencer : System.IDisposable
+    {
+        public TestSequencer() { }
+        public long CompletedPhases { get; }
+        public long CurrentPhase { get; }
+        public System.Threading.Tasks.Task AdvancePhaseAsync(string comment = "") { }
+        public void Dispose() { }
+        protected virtual void Dispose(bool disposing) { }
+    }
 }

src/ReactiveUI.Tests/Activation/ActivatingViewTests.cs

@@ -26,9 +26,10 @@ public void ActivatingViewSmokeTest()
             using (locator.WithResolver())
             {
                 var vm = new ActivatingViewModel();
-                var fixture = new ActivatingView();
-
-                fixture.ViewModel = vm;
+                var fixture = new ActivatingView
+                {
+                    ViewModel = vm
+                };
                 Assert.Equal(0, vm.IsActiveCount);
                 Assert.Equal(0, fixture.IsActiveCount);
 
@@ -56,9 +57,10 @@ public void NullingViewModelDeactivateIt()
             using (locator.WithResolver())
             {
                 var vm = new ActivatingViewModel();
-                var fixture = new ActivatingView();
-
-                fixture.ViewModel = vm;
+                var fixture = new ActivatingView
+                {
+                    ViewModel = vm
+                };
                 Assert.Equal(0, vm.IsActiveCount);
                 Assert.Equal(0, fixture.IsActiveCount);
 
@@ -151,9 +153,10 @@ public void CanUnloadAndLoadViewAgain()
             using (locator.WithResolver())
             {
                 var vm = new ActivatingViewModel();
-                var fixture = new ActivatingView();
-
-                fixture.ViewModel = vm;
+                var fixture = new ActivatingView
+                {
+                    ViewModel = vm
+                };
                 Assert.Equal(0, vm.IsActiveCount);
                 Assert.Equal(0, fixture.IsActiveCount);
 

src/ReactiveUI.Tests/BindingTypeConvertersTest.cs

@@ -7,8 +7,6 @@
 
 namespace ReactiveUI.Tests
 {
-    using System;
-
     /// <summary>
     /// Tests for binding type converters.
     /// </summary>
@@ -66,7 +64,7 @@ public void EqualityTypeConverterDoReferenceCastNullableToValueType()
         [Fact]
         public void EqualityTypeConverterDoReferenceCastShouldConvertValueTypes()
         {
-            var doubleValue = 1.0;
+            const double doubleValue = 1.0;
             var result = EqualityTypeConverter.DoReferenceCast(doubleValue, typeof(double));
             Assert.Equal(doubleValue, result);
         }

src/ReactiveUI.Tests/Commands/ReactiveCommandTest.cs

@@ -1199,25 +1199,21 @@ public async Task ReactiveCommandCreateFromTaskHandlesTaskExceptionAsync()
         [Fact]
         public async Task ReactiveCommandExecutesFromInvokeCommand()
         {
-            var semaphore = new SemaphoreSlim(0);
-            var command = ReactiveCommand.Create(() => semaphore.Release());
+            using var testSequencer = new TestSequencer();
+
+            var command = ReactiveCommand.Create(async () => await testSequencer.AdvancePhaseAsync("Phase 1"));
+            var result = 0;
+
+            // False, True, False
+            command.IsExecuting.Subscribe(_ => result++);
 
             Observable.Return(Unit.Default)
                       .InvokeCommand(command);
 
-            var result = 0;
-            var task = semaphore.WaitAsync();
-            if (await Task.WhenAny(Task.Delay(TimeSpan.FromMilliseconds(100)), task).ConfigureAwait(true) == task)
-            {
-                result = 1;
-            }
-            else
-            {
-                result = -1;
-            }
+            await testSequencer.AdvancePhaseAsync("Phase 1");
+            Assert.Equal(3, result);
 
-            await Task.Delay(200).ConfigureAwait(false);
-            Assert.Equal(1, result);
+            testSequencer.Dispose();
         }
     }
 }

src/ReactiveUI.Tests/Locator/DefaultViewLocatorTests.cs

@@ -13,7 +13,7 @@ namespace ReactiveUI.Tests
     public class DefaultViewLocatorTests
     {
         /// <summary>
-        /// Tests that the the default name of the view model is replaced with view when determining the service.
+        /// Tests that the default name of the view model is replaced with view when determining the service.
         /// </summary>
         [Fact]
         public void ByDefaultViewModelIsReplacedWithViewWhenDeterminingTheServiceName()
@@ -70,9 +70,11 @@ public void ViewModelToViewNamingConventionCanBeCustomized()
 
             using (resolver.WithResolver())
             {
-                var fixture = new DefaultViewLocator();
-                fixture.ViewModelToViewFunc =
-                    viewModelName => viewModelName.Replace("ViewModel", "WithWeirdConvention");
+                var fixture = new DefaultViewLocator
+                {
+                    ViewModelToViewFunc =
+                    viewModelName => viewModelName.Replace("ViewModel", "WithWeirdConvention")
+                };
                 var vm = new FooViewModel();
 
                 var result = fixture.ResolveView(vm);
@@ -254,9 +256,11 @@ public void NoErrorIsRaisedIfATypeCannotBeFound()
 
             using (resolver.WithResolver())
             {
-                var fixture = new DefaultViewLocator();
-                fixture.ViewModelToViewFunc = viewModelName =>
-                    "DoesNotExist, " + typeof(DefaultViewLocatorTests).Assembly.FullName;
+                var fixture = new DefaultViewLocator
+                {
+                    ViewModelToViewFunc = viewModelName =>
+                    "DoesNotExist, " + typeof(DefaultViewLocatorTests).Assembly.FullName
+                };
                 var vm = new FooViewModel();
 
                 var result = fixture.ResolveView(vm);
@@ -386,8 +390,10 @@ public void CanOverrideNameResolutionFunc()
 
             using (resolver.WithResolver())
             {
-                var fixture = new DefaultViewLocator();
-                fixture.ViewModelToViewFunc = x => x.Replace("ViewModel", "CustomView");
+                var fixture = new DefaultViewLocator
+                {
+                    ViewModelToViewFunc = x => x.Replace("ViewModel", "CustomView")
+                };
                 var vm = new RoutableFooViewModel();
 
                 var result = fixture.ResolveView<IRoutableViewModel>(vm);