/
ToObservable.cs
365 lines (314 loc) · 9.76 KB
/
ToObservable.cs
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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the Apache 2.0 License.
// See the LICENSE file in the project root for more information.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Xunit;
namespace Tests
{
public class ToObservable : AsyncEnumerableTests
{
[Fact]
public void ToObservable_Null()
{
Assert.Throws<ArgumentNullException>(() => AsyncEnumerable.ToObservable<int>(null));
}
[Fact]
public void ToObservable1()
{
using var evt = new ManualResetEvent(false);
var fail = false;
var xs = AsyncEnumerable.Empty<int>().ToObservable();
xs.Subscribe(new MyObserver<int>(
x =>
{
fail = true;
},
ex =>
{
fail = true;
evt.Set();
},
() =>
{
evt.Set();
}
));
evt.WaitOne();
Assert.False(fail);
}
[Fact]
public void ToObservable2()
{
using var evt = new ManualResetEvent(false);
var lst = new List<int>();
var fail = false;
var xs = Return42.ToObservable();
xs.Subscribe(new MyObserver<int>(
x =>
{
lst.Add(x);
},
ex =>
{
fail = true;
evt.Set();
},
() =>
{
evt.Set();
}
));
evt.WaitOne();
Assert.False(fail);
Assert.True(lst.SequenceEqual(new[] { 42 }));
}
[Fact]
public void ToObservable3()
{
using var evt = new ManualResetEvent(false);
var lst = new List<int>();
var fail = false;
var xs = AsyncEnumerable.Range(0, 10).ToObservable();
xs.Subscribe(new MyObserver<int>(
x =>
{
lst.Add(x);
},
ex =>
{
fail = true;
evt.Set();
},
() =>
{
evt.Set();
}
));
evt.WaitOne();
Assert.False(fail);
Assert.True(lst.SequenceEqual(Enumerable.Range(0, 10)));
}
[Fact]
public void ToObservable_ThrowOnMoveNext()
{
using var evt = new ManualResetEvent(false);
var ex1 = new Exception("Bang!");
var ex_ = default(Exception);
var fail = false;
var xs = Throw<int>(ex1).ToObservable();
xs.Subscribe(new MyObserver<int>(
x =>
{
fail = true;
},
ex =>
{
ex_ = ex;
evt.Set();
},
() =>
{
fail = true;
evt.Set();
}
));
evt.WaitOne();
Assert.False(fail);
Assert.Equal(ex1, ex_);
}
[Fact]
public void ToObservable_ThrowOnCurrent()
{
var ex1 = new Exception("Bang!");
var ex_ = default(Exception);
var fail = false;
var ae = AsyncEnumerable.Create(
_ => new ThrowOnCurrentAsyncEnumerator(ex1)
);
ae.ToObservable()
.Subscribe(new MyObserver<int>(
x =>
{
fail = true;
},
ex =>
{
ex_ = ex;
},
() =>
{
fail = true;
}
));
Assert.False(fail);
Assert.Equal(ex1, ex_);
}
[Fact]
public void ToObservable_DisposesEnumeratorOnCompletion()
{
using var evt = new ManualResetEvent(false);
var fail = false;
var ae = AsyncEnumerable.Create(
_ => AsyncEnumerator.Create<int>(
() => new ValueTask<bool>(false),
() => { throw new InvalidOperationException(); },
() => { evt.Set(); return default; }));
ae
.ToObservable()
.Subscribe(new MyObserver<int>(
x =>
{
fail = true;
},
ex =>
{
fail = true;
},
() =>
{
}
));
evt.WaitOne();
Assert.False(fail);
}
[Fact]
public void ToObservable_DisposesEnumeratorWhenSubscriptionIsDisposed()
{
using var evt = new ManualResetEvent(false);
var fail = false;
var subscription = default(IDisposable);
var subscriptionAssignedTcs = new TaskCompletionSource<object>();
var ae = AsyncEnumerable.Create(
_ => AsyncEnumerator.Create(
async () =>
{
await subscriptionAssignedTcs.Task;
return true;
},
() => 1,
() =>
{
evt.Set();
return default;
}));
subscription = ae
.ToObservable()
.Subscribe(new MyObserver<int>(
x =>
{
Assert.NotNull(subscription);
subscription!.Dispose();
},
ex =>
{
fail = true;
},
() =>
{
fail = true;
}
));
subscriptionAssignedTcs.SetResult(null);
evt.WaitOne();
Assert.False(fail);
}
[Fact]
public void ToObservable_DesNotCallMoveNextAgainWhenSubscriptionIsDisposed()
{
using var evt = new ManualResetEvent(false);
var fail = false;
var moveNextCount = 0;
var subscription = default(IDisposable);
var subscriptionAssignedTcs = new TaskCompletionSource<object>();
var ae = AsyncEnumerable.Create(
_ => AsyncEnumerator.Create(
async () =>
{
await subscriptionAssignedTcs.Task;
moveNextCount++;
return true;
},
() => 1,
() =>
{
evt.Set();
return default;
}));
subscription = ae
.ToObservable()
.Subscribe(new MyObserver<int>(
x =>
{
Assert.NotNull(subscription);
subscription!.Dispose();
},
ex =>
{
fail = true;
},
() =>
{
fail = true;
}
));
subscriptionAssignedTcs.SetResult(null);
evt.WaitOne();
Assert.Equal(1, moveNextCount);
Assert.False(fail);
}
[Fact]
public void ToObservable_SupportsLargeEnumerable()
{
using var evt = new ManualResetEvent(false);
var fail = false;
var xs = AsyncEnumerable.Range(0, 10000).ToObservable();
xs.Subscribe(new MyObserver<int>(
x =>
{
// ok
},
ex =>
{
fail = true;
evt.Set();
},
() =>
{
evt.Set();
}
));
evt.WaitOne();
Assert.False(fail);
}
private sealed class MyObserver<T> : IObserver<T>
{
private readonly Action<T> _onNext;
private readonly Action<Exception> _onError;
private readonly Action _onCompleted;
public MyObserver(Action<T> onNext, Action<Exception> onError, Action onCompleted)
{
_onNext = onNext;
_onError = onError;
_onCompleted = onCompleted;
}
public void OnCompleted() => _onCompleted();
public void OnError(Exception error) => _onError(error);
public void OnNext(T value) => _onNext(value);
}
private sealed class ThrowOnCurrentAsyncEnumerator : IAsyncEnumerator<int>
{
readonly private Exception _exception;
public ThrowOnCurrentAsyncEnumerator(Exception ex)
{
_exception = ex;
}
public int Current => throw _exception;
public ValueTask DisposeAsync() => default;
public ValueTask<bool> MoveNextAsync() => new ValueTask<bool>(true);
}
}
}