feat: add ActiveTimers property

Author: egil

CHANGELOG.md

@@ -5,6 +5,10 @@ All notable changes to TimeProviderExtensions will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.0.0-rc.2]
+
+- Added `ActiveTimers` property to `ManualTimeProvider`. The property will display the number of currently active timers that have a callback scheduled to be called in the future.
+
 ## [1.0.0-rc.1]
 
 - Updated Microsoft.Bcl.TimeProvider package dependency to rc.1 version.

docs/TimeProviderExtensions.ManualTimeProvider.md

@@ -78,6 +78,19 @@ Optional local time zone to use during testing. Defaults to [System.TimeZoneInfo
 The provider is set to not automatically advance time each time it is read.
 ### Properties
 
+<a name='TimeProviderExtensions.ManualTimeProvider.ActiveTimers'></a>
+
+## ManualTimeProvider.ActiveTimers Property
+
+Gets the number of active [TimeProviderExtensions.ManualTimeProvider.ManualTimer](https://docs.microsoft.com/en-us/dotnet/api/TimeProviderExtensions.ManualTimeProvider.ManualTimer 'TimeProviderExtensions.ManualTimeProvider.ManualTimer'), that have callbacks that are scheduled to be triggered at some point in the future.
+
+```csharp
+public int ActiveTimers { get; }
+```
+
+#### Property Value
+[System.Int32](https://docs.microsoft.com/en-us/dotnet/api/System.Int32 'System.Int32')
+
 <a name='TimeProviderExtensions.ManualTimeProvider.AutoAdvanceAmount'></a>
 
 ## ManualTimeProvider.AutoAdvanceAmount Property

src/TimeProviderExtensions/ManualTimeProvider.cs

@@ -9,7 +9,7 @@ namespace TimeProviderExtensions;
 /// <remarks>
 /// Learn more at <see href="https://github.com/egil/TimeProviderExtensions"/>.
 /// </remarks>
-[DebuggerDisplay("UtcNow: {ToString(),nq}. Scheduled timer callbacks: {callbacks.Count}. Auto advance amount: {autoAdvanceAmount,nq}.")]
+[DebuggerDisplay("UtcNow: {ToString(),nq}. Active timers: {ActiveTimers}. Auto advance amount: {AutoAdvanceAmount,nq}.")]
 public partial class ManualTimeProvider : TimeProvider
 {
     internal const uint MaxSupportedTimeout = 0xfffffffe;
@@ -22,9 +22,9 @@ public partial class ManualTimeProvider : TimeProvider
     private TimeSpan autoAdvanceAmount = TimeSpan.Zero;
 
     /// <summary>
-    /// Gets the number of callbacks that are scheduled to be triggered in the future.
+    /// Gets the number of active <see cref="ManualTimer"/>, that have callbacks that are scheduled to be triggered at some point in the future.
     /// </summary>
-    internal int ScheduledCallbacks => callbacks.Count;
+    public int ActiveTimers => callbacks.Count;
 
     /// <summary>
     /// Gets the starting date and time for this provider.

test/TimeProviderExtensions.Tests/ManualTimeProviderTests.cs

@@ -159,4 +159,43 @@ public void Timer_callback_GetUtcNow_AutoAdvance()
 
         timeProvider.GetUtcNow().Should().Be(timeProvider.Start + oneSecond);
     }
+
+    [Fact]
+    public void ActiveTimers_with_no_timers()
+    {
+        var sut = new ManualTimeProvider();
+
+        sut.ActiveTimers.Should().Be(0);
+    }
+
+    [Fact]
+    public void ActiveTimers_with_active_timers()
+    {
+        var sut = new ManualTimeProvider();
+
+        var timer = sut.CreateTimer(_ => { }, null, 1.Seconds(), Timeout.InfiniteTimeSpan);
+
+        sut.ActiveTimers.Should().Be(1);
+    }
+
+    [Fact]
+    public void ActiveTimers_with_inactive_timers()
+    {
+        var sut = new ManualTimeProvider();
+
+        var timer = sut.CreateTimer(_ => { }, null, Timeout.InfiniteTimeSpan, Timeout.InfiniteTimeSpan);
+
+        sut.ActiveTimers.Should().Be(0);
+    }
+
+    [Fact]
+    public void ActiveTimers_with_after_timer_state_change()
+    {
+        var sut = new ManualTimeProvider();
+
+        var timer = sut.CreateTimer(_ => { }, null, 1.Seconds(), Timeout.InfiniteTimeSpan);
+        sut.Advance(1.Seconds());
+
+        sut.ActiveTimers.Should().Be(0);
+    }
 }

test/TimeProviderExtensions.Tests/Microsoft.Extensions.Time.Testing.Test/TimerTests.cs

@@ -210,20 +210,20 @@ public void WaiterRemovedAfterDispose()
         var timer2Counter = 0;
 
         var timeProvider = new FakeTimeProvider();
-        var waitersCountStart = timeProvider.ScheduledCallbacks;
+        var waitersCountStart = timeProvider.ActiveTimers;
 
         var timer1 = timeProvider.CreateTimer(_ => timer1Counter++, null, TimeSpan.FromMilliseconds(1), TimeSpan.FromMilliseconds(1));
         var timer2 = timeProvider.CreateTimer(_ => timer2Counter++, null, TimeSpan.FromMilliseconds(1), TimeSpan.FromMilliseconds(1));
 
-        var waitersCountDuring = timeProvider.ScheduledCallbacks;
+        var waitersCountDuring = timeProvider.ActiveTimers;
 
         timeProvider.Advance(TimeSpan.FromMilliseconds(1));
 
         timer1.Dispose();
 
         timeProvider.Advance(TimeSpan.FromMilliseconds(1));
 
-        var waitersCountAfter = timeProvider.ScheduledCallbacks;
+        var waitersCountAfter = timeProvider.ActiveTimers;
 
         Assert.Equal(0, waitersCountStart);
         Assert.Equal(2, waitersCountDuring);

test/TimeProviderExtensions.Tests/Usings.cs

@@ -1,4 +1,5 @@
 global using System;
 global using System.Threading;
 global using FluentAssertions;
+global using FluentAssertions.Extensions;
 global using Xunit;