PeriodicTimer in C#: net10.0, timer disposal and behaviour tests

threads-csharp/PeriodicTimerCSharp/PeriodicTimerCSharp/PeriodicTimerCSharp.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>

threads-csharp/PeriodicTimerCSharp/PeriodicTimerCSharp/PeriodicTimerMethods.cs

@@ -46,7 +46,7 @@ private async Task RandomArrayTimerAsync()
                     Console.WriteLine(item);
                 }
 
-                Console.WriteLine($"Created {numberOfArrays++} arrays in {stopWatch.Elapsed.Seconds}s");
+                Console.WriteLine($"Created {numberOfArrays++} arrays in {stopWatch.Elapsed.TotalSeconds:F1}s");
                 Console.WriteLine(DateTime.Now.ToString("O"));
             }
         }
@@ -65,6 +65,7 @@ public async Task StopTaskAsync()
         _cancellationToken.Cancel();
         await _task;
         _cancellationToken.Dispose();
+        _periodicTimer.Dispose();
         Console.WriteLine("The array task was canceled");
     }
 }

threads-csharp/PeriodicTimerCSharp/PeriodicTimerCSharp/Program.cs

@@ -6,7 +6,7 @@
 var timerTask = new PeriodicTimerMethods(TimeSpan.FromSeconds(1), numOfElements);
 timerTask.Start();
 
-Console.WriteLine("Press any button to terminate the task");
+Console.WriteLine("Press any key to stop the task");
 Console.ReadKey();
 
 await timerTask.StopTaskAsync();

threads-csharp/PeriodicTimerCSharp/PeriodicTimerCSharpTests/PeriodicTimerBehaviorTests.cs

@@ -0,0 +1,61 @@
+using Microsoft.Extensions.Time.Testing;
+
+namespace PeriodicTimerCSharpTests;
+
+[TestClass]
+public class PeriodicTimerBehaviorTests
+{
+    [TestMethod]
+    public async Task GivenMissedTicks_WhenWeWaitAgain_ThenTheyCollapseIntoOne()
+    {
+        var time = new FakeTimeProvider();
+        using var timer = new PeriodicTimer(TimeSpan.FromSeconds(1), time);
+
+        time.Advance(TimeSpan.FromSeconds(3.5));
+
+        Assert.IsTrue(await timer.WaitForNextTickAsync());
+
+        var nextTick = timer.WaitForNextTickAsync();
+        Assert.IsFalse(nextTick.IsCompleted);
+
+        time.Advance(TimeSpan.FromSeconds(0.5));
+        Assert.IsTrue(await nextTick);
+    }
+
+    [TestMethod]
+    public void GivenAWaitInFlight_WhenWeWaitTwice_ThenTheSecondCallThrows()
+    {
+        using var timer = new PeriodicTimer(TimeSpan.FromSeconds(1));
+
+        _ = timer.WaitForNextTickAsync();
+
+        Assert.ThrowsExactly<InvalidOperationException>(() => timer.WaitForNextTickAsync());
+    }
+
+    [TestMethod]
+    public async Task GivenAWaitInFlight_WhenWeDisposeTheTimer_ThenTheWaitReturnsFalse()
+    {
+        var timer = new PeriodicTimer(TimeSpan.FromSeconds(1));
+        var tick = timer.WaitForNextTickAsync();
+
+        timer.Dispose();
+
+        Assert.IsFalse(await tick);
+    }
+
+    [TestMethod]
+    public void GivenANewPeriod_WhenTimePasses_ThenTheTimerTicksOnTheNewSchedule()
+    {
+        var time = new FakeTimeProvider();
+        using var timer = new PeriodicTimer(TimeSpan.FromSeconds(1), time);
+
+        timer.Period = TimeSpan.FromSeconds(5);
+        var tick = timer.WaitForNextTickAsync();
+
+        time.Advance(TimeSpan.FromSeconds(4));
+        Assert.IsFalse(tick.IsCompleted);
+
+        time.Advance(TimeSpan.FromSeconds(1));
+        Assert.IsTrue(tick.IsCompleted);
+    }
+}

threads-csharp/PeriodicTimerCSharp/PeriodicTimerCSharpTests/PeriodicTimerCSharpTests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
 
@@ -10,10 +10,11 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
-    <PackageReference Include="MSTest.TestAdapter" Version="3.1.1" />
-    <PackageReference Include="MSTest.TestFramework" Version="3.1.1" />
-    <PackageReference Include="coverlet.collector" Version="6.0.0">
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.11.0" />
+    <PackageReference Include="MSTest.TestAdapter" Version="4.5.2" />
+    <PackageReference Include="MSTest.TestFramework" Version="4.5.2" />
+    <PackageReference Include="Microsoft.Extensions.TimeProvider.Testing" Version="10.11.0" />
+    <PackageReference Include="coverlet.collector" Version="10.1.0">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>