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.NET-Community-Toolkit/tests/CommunityToolkit.Mvvm.UnitTests/Test_AsyncRelayCommand.cs
2022-06-04 16:37:33 +02:00

599 lines
19 KiB
C#

// 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 more information.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Threading.Tasks;
using System.Windows.Input;
using CommunityToolkit.Mvvm.Input;
using CommunityToolkit.Mvvm.UnitTests.Helpers;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Nito.AsyncEx;
namespace CommunityToolkit.Mvvm.UnitTests;
[TestClass]
public class Test_AsyncRelayCommand
{
[TestMethod]
public async Task Test_AsyncRelayCommand_AlwaysEnabled()
{
int ticks = 0;
AsyncRelayCommand? command = new(async () =>
{
await Task.Delay(1000);
ticks++;
await Task.Delay(1000);
});
Assert.IsTrue(command.CanExecute(null));
Assert.IsTrue(command.CanExecute(new object()));
Assert.IsFalse(command.CanBeCanceled);
Assert.IsFalse(command.IsCancellationRequested);
(object?, EventArgs?) args = default;
command.CanExecuteChanged += (s, e) => args = (s, e);
command.NotifyCanExecuteChanged();
Assert.AreSame(args.Item1, command);
Assert.AreSame(args.Item2, EventArgs.Empty);
Assert.IsNull(command.ExecutionTask);
Assert.IsFalse(command.IsRunning);
Task task = command.ExecuteAsync(null);
Assert.IsNotNull(command.ExecutionTask);
Assert.AreSame(command.ExecutionTask, task);
Assert.IsTrue(command.IsRunning);
await task;
Assert.IsFalse(command.IsRunning);
Assert.AreEqual(ticks, 1);
command.Execute(new object());
await command.ExecutionTask!;
Assert.AreEqual(ticks, 2);
}
[TestMethod]
public void Test_AsyncRelayCommand_WithCanExecuteFunctionTrue()
{
int ticks = 0;
AsyncRelayCommand? command = new(
() =>
{
ticks++;
return Task.CompletedTask;
}, () => true);
Assert.IsTrue(command.CanExecute(null));
Assert.IsTrue(command.CanExecute(new object()));
Assert.IsFalse(command.CanBeCanceled);
Assert.IsFalse(command.IsCancellationRequested);
command.Execute(null);
Assert.AreEqual(ticks, 1);
command.Execute(new object());
Assert.AreEqual(ticks, 2);
}
[TestMethod]
public void Test_AsyncRelayCommand_WithCanExecuteFunctionFalse()
{
int ticks = 0;
AsyncRelayCommand? command = new(
() =>
{
ticks++;
return Task.CompletedTask;
}, () => false);
Assert.IsFalse(command.CanExecute(null));
Assert.IsFalse(command.CanExecute(new object()));
Assert.IsFalse(command.CanBeCanceled);
Assert.IsFalse(command.IsCancellationRequested);
command.Execute(null);
// It is the caller's responsibility to ensure that CanExecute is true
// before calling Execute. This check verifies the logic is still called.
Assert.AreEqual(ticks, 1);
command.Execute(new object());
Assert.AreEqual(ticks, 2);
}
[TestMethod]
public async Task Test_AsyncRelayCommand_WithCancellation()
{
TaskCompletionSource<object?> tcs = new();
// We need to test the cancellation support here, so we use the overload with an input
// parameter, which is a cancellation token. The token is the one that is internally managed
// by the AsyncRelayCommand instance, and canceled when using IAsyncRelayCommand.Cancel().
AsyncRelayCommand? command = new(token => tcs.Task);
List<PropertyChangedEventArgs> args = new();
command.PropertyChanged += (s, e) => args.Add(e);
// We have no canExecute parameter, so the command can always be invoked
Assert.IsTrue(command.CanExecute(null));
Assert.IsTrue(command.CanExecute(new object()));
// The command isn't running, so it can't be canceled yet
Assert.IsFalse(command.CanBeCanceled);
Assert.IsFalse(command.IsCancellationRequested);
// Start the command, which will return the token from our task completion source.
// We can use that to easily keep the command running while we do our tests, and then
// stop the processing by completing the source when we need (see below).
command.Execute(null);
// The command is running, so it can be canceled, as we used the token overload
Assert.IsTrue(command.CanBeCanceled);
Assert.IsFalse(command.IsCancellationRequested);
// Validate the various event args for all the properties that were updated when executing the command
Assert.AreEqual(args.Count, 4);
Assert.AreEqual(args[0].PropertyName, nameof(IAsyncRelayCommand.ExecutionTask));
Assert.AreEqual(args[1].PropertyName, nameof(IAsyncRelayCommand.IsRunning));
Assert.AreEqual(args[2].PropertyName, nameof(IAsyncRelayCommand.CanBeCanceled));
Assert.AreEqual(args[3].PropertyName, nameof(IAsyncRelayCommand.IsCancellationRequested));
command.Cancel();
// Verify that these two properties raised notifications correctly when canceling the command too.
// We need to ensure all command properties support notifications so that users can bind to them.
Assert.AreEqual(args.Count, 6);
Assert.AreEqual(args[4].PropertyName, nameof(IAsyncRelayCommand.CanBeCanceled));
Assert.AreEqual(args[5].PropertyName, nameof(IAsyncRelayCommand.IsCancellationRequested));
Assert.IsTrue(command.IsCancellationRequested);
// Complete the source, which will mark the command as completed too (as it returned the same task)
tcs.SetResult(null);
await command.ExecutionTask!;
// Verify that the command can no longer be canceled, and that the cancellation is
// instead still true, as that's reset when executing a command and not on completion.
Assert.IsFalse(command.CanBeCanceled);
Assert.IsTrue(command.IsCancellationRequested);
}
[TestMethod]
public async Task Test_AsyncRelayCommand_AllowConcurrentExecutions_Enable()
{
int index = 0;
TaskCompletionSource<object?>[] cancellationTokenSources = new TaskCompletionSource<object?>[]
{
new TaskCompletionSource<object?>(),
new TaskCompletionSource<object?>()
};
AsyncRelayCommand? command = new(() => cancellationTokenSources[index++].Task, AsyncRelayCommandOptions.AllowConcurrentExecutions);
Assert.IsTrue(command.CanExecute(null));
Assert.IsTrue(command.CanExecute(new object()));
Assert.IsFalse(command.CanBeCanceled);
Assert.IsFalse(command.IsCancellationRequested);
(object?, EventArgs?) args = default;
command.CanExecuteChanged += (s, e) => args = (s, e);
command.NotifyCanExecuteChanged();
Assert.AreSame(args.Item1, command);
Assert.AreSame(args.Item2, EventArgs.Empty);
args = default;
Assert.IsNull(command.ExecutionTask);
Assert.IsFalse(command.IsRunning);
Task task = command.ExecuteAsync(null);
Assert.IsNotNull(command.ExecutionTask);
Assert.AreSame(command.ExecutionTask, task);
Assert.AreSame(command.ExecutionTask, cancellationTokenSources[0].Task);
Assert.IsTrue(command.IsRunning);
// The command can still be executed now
Assert.IsTrue(command.CanExecute(null));
Assert.IsTrue(command.CanExecute(new object()));
Assert.IsFalse(command.CanBeCanceled);
Assert.IsFalse(command.IsCancellationRequested);
Task newTask = command.ExecuteAsync(null);
// A new task was returned
Assert.AreSame(command.ExecutionTask, newTask);
Assert.AreSame(command.ExecutionTask, cancellationTokenSources[1].Task);
cancellationTokenSources[0].SetResult(null);
cancellationTokenSources[1].SetResult(null);
_ = await Task.WhenAll(cancellationTokenSources[0].Task, cancellationTokenSources[1].Task);
Assert.IsFalse(command.IsRunning);
// CanExecute isn't raised again when the command completes, if concurrent executions are allowed
Assert.IsNull(args.Item1);
Assert.IsNull(args.Item2);
}
[TestMethod]
public async Task Test_AsyncRelayCommand_AllowConcurrentExecutions_Disabled()
{
await Test_AsyncRelayCommand_AllowConcurrentExecutions_TestLogic(static task => new(async () => await task, AsyncRelayCommandOptions.None));
}
[TestMethod]
public async Task Test_AsyncRelayCommand_AllowConcurrentExecutions_Default()
{
await Test_AsyncRelayCommand_AllowConcurrentExecutions_TestLogic(static task => new(async () => await task));
}
/// <summary>
/// Shared logic for <see cref="Test_AsyncRelayCommand_AllowConcurrentExecutions_Disabled"/> and <see cref="Test_AsyncRelayCommand_AllowConcurrentExecutions_Default"/>.
/// </summary>
/// <param name="factory">A factory to create the <see cref="AsyncRelayCommand"/> instance to test.</param>
private static async Task Test_AsyncRelayCommand_AllowConcurrentExecutions_TestLogic(Func<Task, AsyncRelayCommand> factory)
{
TaskCompletionSource<object?> tcs = new();
AsyncRelayCommand? command = factory(tcs.Task);
Assert.IsTrue(command.CanExecute(null));
Assert.IsTrue(command.CanExecute(new object()));
Assert.IsFalse(command.CanBeCanceled);
Assert.IsFalse(command.IsCancellationRequested);
(object?, EventArgs?) args = default;
command.CanExecuteChanged += (s, e) => args = (s, e);
command.NotifyCanExecuteChanged();
Assert.AreSame(args.Item1, command);
Assert.AreSame(args.Item2, EventArgs.Empty);
args = default;
Assert.IsNull(command.ExecutionTask);
Assert.IsFalse(command.IsRunning);
Task task = command.ExecuteAsync(null);
// CanExecute is raised upon execution
Assert.AreSame(args.Item1, command);
Assert.AreSame(args.Item2, EventArgs.Empty);
args = default;
Assert.IsNotNull(command.ExecutionTask);
Assert.AreSame(command.ExecutionTask, task);
Assert.IsTrue(command.IsRunning);
// The command can't be executed now, as there's a pending operation
Assert.IsFalse(command.CanExecute(null));
Assert.IsFalse(command.CanExecute(new object()));
Assert.IsFalse(command.CanBeCanceled);
Assert.IsFalse(command.IsCancellationRequested);
// CanExecute hasn't been raised again
Assert.IsNull(args.Item1);
Assert.IsNull(args.Item2);
tcs.SetResult(null);
await task;
Assert.IsFalse(command.IsRunning);
// CanExecute is raised automatically when command execution completes, if concurrent executions are disabled
Assert.AreSame(args.Item1, command);
Assert.AreSame(args.Item2, EventArgs.Empty);
}
[TestMethod]
public void Test_AsyncRelayCommand_EnsureExceptionThrown_Synchronously()
{
Exception? executeException = null;
AsyncRelayCommand command = new(async () =>
{
await Task.CompletedTask;
throw new Exception(nameof(Test_AsyncRelayCommand_EnsureExceptionThrown_Synchronously));
});
try
{
AsyncContext.Run(async () =>
{
command.Execute(null);
await Task.Delay(500);
});
}
catch (Exception e)
{
executeException = e;
}
Assert.AreEqual(nameof(Test_AsyncRelayCommand_EnsureExceptionThrown_Synchronously), executeException?.Message);
}
// See https://github.com/CommunityToolkit/dotnet/pull/251
[TestMethod]
public async Task Test_AsyncRelayCommand_EnsureExceptionThrown()
{
const int delay = 500;
Exception? executeException = null;
Exception? executeAsyncException = null;
AsyncRelayCommand command = new(async () =>
{
await Task.Delay(delay);
throw new Exception(nameof(Test_AsyncRelayCommand_EnsureExceptionThrown));
});
try
{
// Use AsyncContext to test async void methods https://stackoverflow.com/a/14207615/5953643
AsyncContext.Run(async () =>
{
command.Execute(null);
await Task.Delay(delay * 2); // Ensure we don't escape `AsyncContext` before command throws Exception
});
}
catch (Exception e)
{
executeException = e;
}
executeAsyncException = await Assert.ThrowsExceptionAsync<Exception>(() => command.ExecuteAsync(null));
Assert.AreEqual(nameof(Test_AsyncRelayCommand_EnsureExceptionThrown), executeException?.Message);
Assert.AreEqual(nameof(Test_AsyncRelayCommand_EnsureExceptionThrown), executeAsyncException?.Message);
}
[TestMethod]
public async Task Test_AsyncRelayCommand_ThrowingTaskBubblesToUnobservedTaskException()
{
static async Task TestMethodAsync(Action action)
{
await Task.Delay(100);
action();
}
async void TestCallback(Action throwAction, Action completeAction)
{
AsyncRelayCommand command = new(() => TestMethodAsync(throwAction), AsyncRelayCommandOptions.FlowExceptionsToTaskScheduler);
command.Execute(null);
await Task.Delay(200);
completeAction();
}
bool success = await TaskSchedulerTestHelper.IsExceptionBubbledUpToUnobservedTaskExceptionAsync(TestCallback);
Assert.IsTrue(success);
}
[TestMethod]
public async Task Test_AsyncRelayCommand_ThrowingTaskBubblesToUnobservedTaskException_Synchronously()
{
static async Task TestMethodAsync(Action action)
{
await Task.CompletedTask;
action();
}
async void TestCallback(Action throwAction, Action completeAction)
{
AsyncRelayCommand command = new(() => TestMethodAsync(throwAction), AsyncRelayCommandOptions.FlowExceptionsToTaskScheduler);
command.Execute(null);
await Task.Delay(200);
completeAction();
}
bool success = await TaskSchedulerTestHelper.IsExceptionBubbledUpToUnobservedTaskExceptionAsync(TestCallback);
Assert.IsTrue(success);
}
// See https://github.com/CommunityToolkit/dotnet/issues/108
[TestMethod]
public void Test_AsyncRelayCommand_ExecuteDoesNotRaiseCanExecuteChanged()
{
TaskCompletionSource<object?> tcs = new();
AsyncRelayCommand command = new(() => tcs.Task, AsyncRelayCommandOptions.AllowConcurrentExecutions);
(object? Sender, EventArgs? Args) args = default;
command.CanExecuteChanged += (s, e) => args = (s, e);
Assert.IsTrue(command.CanExecute(null));
command.Execute(null);
Assert.IsNull(args.Sender);
Assert.IsNull(args.Args);
Assert.IsTrue(command.CanExecute(null));
tcs.SetResult(null);
}
[TestMethod]
public void Test_AsyncRelayCommand_ExecuteWithoutConcurrencyRaisesCanExecuteChanged()
{
TaskCompletionSource<object?> tcs = new();
AsyncRelayCommand command = new(() => tcs.Task, AsyncRelayCommandOptions.None);
(object? Sender, EventArgs? Args) args = default;
command.CanExecuteChanged += (s, e) => args = (s, e);
Assert.IsTrue(command.CanExecute(null));
command.Execute(null);
Assert.AreSame(command, args.Sender);
Assert.AreSame(EventArgs.Empty, args.Args);
Assert.IsFalse(command.CanExecute(null));
tcs.SetResult(null);
}
[TestMethod]
public void Test_AsyncRelayCommand_ExecuteDoesNotRaiseCanExecuteChanged_WithCancellation()
{
TaskCompletionSource<object?> tcs = new();
AsyncRelayCommand command = new(token => tcs.Task, AsyncRelayCommandOptions.AllowConcurrentExecutions);
(object? Sender, EventArgs? Args) args = default;
command.CanExecuteChanged += (s, e) => args = (s, e);
Assert.IsTrue(command.CanExecute(null));
command.Execute(null);
Assert.IsNull(args.Sender);
Assert.IsNull(args.Args);
Assert.IsTrue(command.CanExecute(null));
tcs.SetResult(null);
}
[TestMethod]
public void Test_AsyncRelayCommand_ExecuteWithoutConcurrencyRaisesCanExecuteChanged_WithToken()
{
TaskCompletionSource<object?> tcs = new();
AsyncRelayCommand command = new(token => tcs.Task, AsyncRelayCommandOptions.None);
(object? Sender, EventArgs? Args) args = default;
command.CanExecuteChanged += (s, e) => args = (s, e);
Assert.IsTrue(command.CanExecute(null));
command.Execute(null);
Assert.AreSame(command, args.Sender);
Assert.AreSame(EventArgs.Empty, args.Args);
Assert.IsFalse(command.CanExecute(null));
tcs.SetResult(null);
}
[TestMethod]
public void Test_AsyncRelayCommand_GetCancelCommand_DisabledCommand()
{
TaskCompletionSource<object?> tcs = new();
AsyncRelayCommand command = new(() => tcs.Task);
ICommand cancelCommand = command.CreateCancelCommand();
Assert.IsNotNull(cancelCommand);
Assert.IsFalse(cancelCommand.CanExecute(null));
// No-op
cancelCommand.Execute(null);
Assert.AreEqual("CommunityToolkit.Mvvm.Input.Internals.DisabledCommand", cancelCommand.GetType().ToString());
ICommand cancelCommand2 = command.CreateCancelCommand();
Assert.IsNotNull(cancelCommand2);
Assert.IsFalse(cancelCommand2.CanExecute(null));
Assert.AreSame(cancelCommand, cancelCommand2);
}
[TestMethod]
public void Test_AsyncRelayCommand_GetCancelCommand_WithToken()
{
TaskCompletionSource<object?> tcs = new();
AsyncRelayCommand command = new(token => tcs.Task);
ICommand cancelCommand = command.CreateCancelCommand();
Assert.IsNotNull(cancelCommand);
Assert.IsFalse(cancelCommand.CanExecute(null));
// No-op
cancelCommand.Execute(null);
Assert.AreEqual("CommunityToolkit.Mvvm.Input.Internals.CancelCommand", cancelCommand.GetType().ToString());
List<(object? Sender, EventArgs Args)> cancelCommandCanExecuteChangedArgs = new();
cancelCommand.CanExecuteChanged += (s, e) => cancelCommandCanExecuteChangedArgs.Add((s, e));
command.Execute(null);
Assert.AreEqual(1, cancelCommandCanExecuteChangedArgs.Count);
Assert.AreSame(cancelCommand, cancelCommandCanExecuteChangedArgs[0].Sender);
Assert.AreSame(EventArgs.Empty, cancelCommandCanExecuteChangedArgs[0].Args);
Assert.IsTrue(cancelCommand.CanExecute(null));
cancelCommand.Execute(null);
Assert.IsFalse(cancelCommand.CanExecute(null));
Assert.AreEqual(2, cancelCommandCanExecuteChangedArgs.Count);
Assert.AreSame(cancelCommand, cancelCommandCanExecuteChangedArgs[1].Sender);
Assert.AreSame(EventArgs.Empty, cancelCommandCanExecuteChangedArgs[1].Args);
Assert.IsFalse(command.CanBeCanceled);
Assert.IsTrue(command.IsCancellationRequested);
}
}