Add extension function on observable to ignore OnComplete events (#1135)

* Adds the possibility to ignore the OnComplete event on subscriptions

* some fixes

* fix after comments

Author: helto4real

src/HassModel/NetDaemon.HassModel.Tests/StateObservableExtensionsTest.cs

@@ -20,6 +20,35 @@ public StateObservableExtensionsTest()
                                                                     EntityState.Map<NumericEntityState>(e.New)));
     }
 
+    [Fact]
+    public void TestThrottleShouldNotCallActionUsingIngoreOnCompleteWhenSubjectCompleted()
+    {
+        bool isCalled = false;
+
+        _subject.Where(n => n?.New?.State == "off").IgnoreOnComplete().Throttle(TimeSpan.FromSeconds(1), _testScheduler).Subscribe(_ => { isCalled = true;});
+
+        _subject.OnNext(new StateChange(new Entity(new Mock<IHaContext>().Object, ""), new EntityState { State = "on" }, new EntityState { State = "off" }));
+
+        _subject.OnCompleted();
+
+        isCalled.Should().BeFalse();
+    }
+
+    [Fact]
+    public void TestThrottleShouldCallActionUsingIngoreOnCompleteInNormalOperation()
+    {
+        bool isCalled = false;
+
+        _subject.Where(n => n?.New?.State == "off").IgnoreOnComplete().Throttle(TimeSpan.FromSeconds(1), _testScheduler).Subscribe(_ => { isCalled = true;});
+
+        _subject.OnNext(new StateChange(new Entity(new Mock<IHaContext>().Object, ""), new EntityState { State = "on" }, new EntityState { State = "off" }));
+
+        _testScheduler.AdvanceBy(TimeSpan.FromSeconds(2).Ticks);
+        _subject.OnCompleted();
+
+        isCalled.Should().BeTrue();
+    }
+
     [Fact]
     public void TestThatWhenStateIsForDoesNotCallActionWhenCompleted()
     {

src/HassModel/NetDeamon.HassModel/StateObservableExtensions.cs

@@ -7,6 +7,17 @@ namespace NetDaemon.HassModel;
 /// </summary>
 public static class StateObservableExtensions
 {
+    /// <summary>
+    /// Ignores the OnCompletion event of the observable
+    /// </summary>
+    /// <remarks>
+    /// This can be used in combination with Throttle() to avoid events to be emitted when the
+    /// observable is completed (eg because the app is stopped). Use IgnoreOnComplete(). before
+    /// Throttle() to make sure Throttle will not send events when the app is stopping.
+    /// </remarks>
+    public static IObservable<T> IgnoreOnComplete<T>(this IObservable<T> source)
+        => Observable.Create<T>(observer => source.Subscribe(observer.OnNext, observer.OnError));
+
     /// <summary>
     /// Waits for an EntityState to match a predicate for the specified time
     /// </summary>