Remove MockTimeProvider

- Remove `MockTimeProvider`.
- Simplify `TimeProviderExtensions` to remove code that duplicates what the extensions in `Microsoft.Bcl.TimeProvider` do.

Author: martincostello

src/Polly.Core/Utils/TimeProviderExtensions.cs

@@ -23,41 +23,23 @@ public static Task DelayAsync(this TimeProvider timeProvider, TimeSpan delay, Re
 
         context.CancellationToken.ThrowIfCancellationRequested();
 
-        if (context.IsSynchronous && timeProvider == TimeProvider.System)
+        if (context.IsSynchronous)
         {
-            // Stryker disable once boolean : no means to test this
-            if (context.CancellationToken.CanBeCanceled)
-            {
-                context.CancellationToken.WaitHandle.WaitOne(delay);
-                context.CancellationToken.ThrowIfCancellationRequested();
-            }
-            else
-            {
-                Thread.Sleep(delay);
-            }
-
-            return Task.CompletedTask;
-        }
-        else
-        {
-            if (context.IsSynchronous)
-            {
 #pragma warning disable CA1849 // For synchronous scenarios we want to return completed task
 #if NET8_0_OR_GREATER
-                Task.Delay(delay, timeProvider, context.CancellationToken).GetAwaiter().GetResult();
+            Task.Delay(delay, timeProvider, context.CancellationToken).GetAwaiter().GetResult();
 #else
-                timeProvider.Delay(delay, context.CancellationToken).GetAwaiter().GetResult();
+            timeProvider.Delay(delay, context.CancellationToken).GetAwaiter().GetResult();
 #endif
 #pragma warning restore CA1849
 
-                return Task.CompletedTask;
-            }
+            return Task.CompletedTask;
+        }
 
 #if NET8_0_OR_GREATER
-            return Task.Delay(delay, timeProvider, context.CancellationToken);
+        return Task.Delay(delay, timeProvider, context.CancellationToken);
 #else
-            return timeProvider.Delay(delay, context.CancellationToken);
+        return timeProvider.Delay(delay, context.CancellationToken);
 #endif
-        }
     }
 }

test/Polly.Core.Tests/Helpers/MockTimeProvider.cs

@@ -10,8 +10,8 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Polly.Contrib.WaitAndRetry" />
     <PackageReference Include="Microsoft.Bcl.TimeProvider"/>
+    <PackageReference Include="Polly.Contrib.WaitAndRetry" />
   </ItemGroup>
 
   <ItemGroup>
@@ -20,7 +20,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <Using Include="Polly.TestUtils" />
     <Using Include="Polly.Core.Tests.Helpers" />
+    <Using Include="Polly.TestUtils" />
   </ItemGroup>
 </Project>

test/Polly.Core.Tests/Polly.Core.Tests.csproj

@@ -1,3 +1,4 @@
+using FluentAssertions.Execution;
 using Microsoft.Extensions.Time.Testing;
 using Moq;
 using Polly.Retry;
@@ -158,40 +159,76 @@ public void Retry_Infinite_Respected()
     [Fact]
     public async Task RetryDelayGenerator_Respected()
     {
-        int calls = 0;
-        _options.OnRetry = _ => { calls++; return default; };
+        int retries = 0;
+        int generatedValues = 0;
+
+        var delay = TimeSpan.FromMilliseconds(120);
+        var provider = TimeProvider.System;
+
         _options.ShouldHandle = _ => PredicateResult.True;
         _options.RetryCount = 3;
         _options.BackoffType = RetryBackoffType.Constant;
-        _options.RetryDelayGenerator = _ => new ValueTask<TimeSpan>(TimeSpan.FromMilliseconds(123));
-        var provider = new MockTimeProvider();
-        provider.SetupCreateTimer(TimeSpan.FromMilliseconds(123));
-        provider.Setup(p => p.GetTimestamp()).Returns(0);
-        provider.Setup(p => p.TimestampFrequency).Returns(10000);
 
-        var sut = CreateSut(provider.Object);
+        _options.OnRetry = _ =>
+        {
+            retries++;
+            return default;
+        };
+        _options.RetryDelayGenerator = _ =>
+        {
+            generatedValues++;
+            return new ValueTask<TimeSpan>(delay);
+        };
+
+        var before = provider.GetUtcNow();
+
+        var sut = CreateSut(provider);
         await sut.ExecuteAsync(_ => default);
 
-        provider.VerifyAll();
+        retries.Should().Be(3);
+        generatedValues.Should().Be(3);
+
+        var after = provider.GetUtcNow();
+        (after - before).Should().BeGreaterThanOrEqualTo(delay.Add(delay).Add(delay));
     }
 
     [Fact]
     public async Task RetryDelayGenerator_ZeroDelay_NoTimeProviderCalls()
     {
-        int calls = 0;
-        _options.OnRetry = _ => { calls++; return default; };
+        int retries = 0;
+        int generatedValues = 0;
+
+        var delay = TimeSpan.Zero;
+        var provider = new ThrowingFakeTimeProvider();
+
         _options.ShouldHandle = _ => PredicateResult.True;
-        _options.RetryCount = 1;
-        _options.RetryDelayGenerator = _ => new ValueTask<TimeSpan>(TimeSpan.FromMilliseconds(0));
-        var provider = new MockTimeProvider();
-        provider.Setup(p => p.GetTimestamp()).Returns(0);
-        provider.Setup(p => p.TimestampFrequency).Returns(10000);
+        _options.RetryCount = 3;
+        _options.BackoffType = RetryBackoffType.Constant;
 
-        var sut = CreateSut(provider.Object);
+        _options.OnRetry = _ =>
+        {
+            retries++;
+            return default;
+        };
+        _options.RetryDelayGenerator = _ =>
+        {
+            generatedValues++;
+            return new ValueTask<TimeSpan>(delay);
+        };
+
+        var sut = CreateSut(provider);
         await sut.ExecuteAsync(_ => default);
 
-        provider.VerifyAll();
-        provider.VerifyNoOtherCalls();
+        retries.Should().Be(3);
+        generatedValues.Should().Be(3);
+    }
+
+    private sealed class ThrowingFakeTimeProvider : FakeTimeProvider
+    {
+        public override DateTimeOffset GetUtcNow() => throw new AssertionFailedException("TimeProvider should not be used.");
+
+        public override ITimer CreateTimer(TimerCallback callback, object? state, TimeSpan dueTime, TimeSpan period)
+            => throw new AssertionFailedException("TimeProvider should not be used.");
     }
 
     [Fact]

test/Polly.Core.Tests/Retry/RetryResilienceStrategyTests.cs

@@ -4,38 +4,27 @@ namespace Polly.Core.Tests.Utils;
 
 public class TimeProviderExtensionsTests
 {
-    [InlineData(false, false, false)]
-    [InlineData(false, false, true)]
-    [InlineData(false, true, true)]
-    [InlineData(false, true, false)]
-    [InlineData(true, false, false)]
-    [InlineData(true, false, true)]
-    [InlineData(true, true, true)]
-    [InlineData(true, true, false)]
+    [InlineData(false, false)]
+    [InlineData(false, true)]
+    [InlineData(true, false)]
+    [InlineData(true, true)]
     [Theory]
-    public async Task DelayAsync_System_Ok(bool synchronous, bool mocked, bool hasCancellation)
+    public async Task DelayAsync_System_Ok(bool synchronous, bool hasCancellation)
     {
         using var tcs = new CancellationTokenSource();
         var token = hasCancellation ? tcs.Token : default;
         var delay = TimeSpan.FromMilliseconds(10);
-        var mock = new MockTimeProvider();
-        var timeProvider = mocked ? mock.Object : TimeProvider.System;
+        var timeProvider = TimeProvider.System;
         var context = ResilienceContext.Get();
         context.Initialize<VoidResult>(isSynchronous: synchronous);
         context.CancellationToken = token;
-        mock.SetupCreateTimer(delay);
 
         await TestUtilities.AssertWithTimeoutAsync(async () =>
         {
             var task = timeProvider.DelayAsync(delay, context);
-            task.IsCompleted.Should().Be(synchronous || mocked);
+            task.IsCompleted.Should().Be(synchronous);
             await task;
         });
-
-        if (mocked)
-        {
-            mock.VerifyAll();
-        }
     }
 
     [Fact]
@@ -72,46 +61,38 @@ await TimeProvider.System
         });
     }
 
-    [InlineData(false, false)]
-    [InlineData(false, true)]
-    [InlineData(true, false)]
-    [InlineData(true, true)]
+    [InlineData(false)]
+    [InlineData(true)]
     [Theory]
-    public async Task DelayAsync_CancellationRequestedBefore_Throws(bool synchronous, bool mocked)
+    public async Task DelayAsync_CancellationRequestedBefore_Throws(bool synchronous)
     {
         using var tcs = new CancellationTokenSource();
         tcs.Cancel();
         var token = tcs.Token;
         var delay = TimeSpan.FromMilliseconds(10);
-        var mock = new MockTimeProvider();
-        var timeProvider = mocked ? mock.Object : TimeProvider.System;
+        var timeProvider = TimeProvider.System;
         var context = ResilienceContext.Get();
         context.Initialize<VoidResult>(isSynchronous: synchronous);
         context.CancellationToken = token;
-        mock.SetupCreateTimer(delay);
 
         await Assert.ThrowsAsync<OperationCanceledException>(() => timeProvider.DelayAsync(delay, context));
     }
 
-    [InlineData(false, false)]
-    [InlineData(false, true)]
-    [InlineData(true, false)]
-    [InlineData(true, true)]
+    [InlineData(false)]
+    [InlineData(true)]
     [Theory]
-    public async Task DelayAsync_CancellationAfter_Throws(bool synchronous, bool mocked)
+    public async Task DelayAsync_CancellationAfter_Throws(bool synchronous)
     {
         var delay = TimeSpan.FromMilliseconds(20);
 
         await TestUtilities.AssertWithTimeoutAsync(async () =>
         {
-            var mock = new MockTimeProvider();
             using var tcs = new CancellationTokenSource();
             var token = tcs.Token;
-            var timeProvider = mocked ? mock.Object : TimeProvider.System;
+            var timeProvider = TimeProvider.System;
             var context = ResilienceContext.Get();
             context.Initialize<VoidResult>(isSynchronous: synchronous);
             context.CancellationToken = token;
-            mock.SetupCreateTimerException(delay, new OperationCanceledException());
 
             tcs.CancelAfter(TimeSpan.FromMilliseconds(5));
 

test/Polly.Core.Tests/Utils/TimeProviderExtensionsTests.cs

@@ -10,7 +10,6 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <Compile Include="..\Polly.Core.Tests\Helpers\MockTimeProvider.cs" Link="Utils\MockTimeProvider.cs" />
     <Compile Include="..\Polly.Core.Tests\Utils\ObjectPoolTests.cs" Link="Utils\ObjectPoolTests.cs" />
   </ItemGroup>
 

test/Polly.Extensions.Tests/Polly.Extensions.Tests.csproj

@@ -11,7 +11,7 @@
   <ItemGroup>
     <Using Remove="System.Net.Http" />
     <ProjectReference Include="..\..\src\Polly.Core\Polly.Core.csproj" />
-    <PackageReference Include="Moq" />
     <PackageReference Include="Microsoft.Extensions.Logging" />
+    <PackageReference Include="Moq" />
   </ItemGroup>
 </Project>