Add new issue test that demonstrates library scenario (#1322)

test/Polly.Extensions.Tests/Issues/IssuesTests.OnCircuitBreakWithServiceProvider_796.cs

@@ -3,7 +3,7 @@
 using Polly.Extensions.DependencyInjection;
 using Polly.Registry;
 
-namespace Polly.Core.Tests.Issues;
+namespace Polly.Extensions.Tests.Issues;
 
 public partial class IssuesTests
 {

test/Polly.Extensions.Tests/Issues/IssuesTests.OverrideLibraryStrategies_1072.cs

@@ -0,0 +1,85 @@
+using System.Net.Sockets;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using Polly.Registry;
+using Polly.Retry;
+
+namespace Polly.Extensions.Tests.Issues;
+
+public partial class IssuesTests
+{
+    [InlineData(true)]
+    [InlineData(false)]
+    [Theory]
+    public void OverrideLibraryStrategies_898(bool overrideStrategy)
+    {
+        // arrange
+        var services = new ServiceCollection();
+        var failFirstCall = true;
+        AddLibraryServices(services);
+
+        if (overrideStrategy)
+        {
+            // This call overrides the strategy that the library uses. The last call to AddResilienceStrategy wins.
+            services.AddResilienceStrategy("library-strategy", builder => builder.AddRetry(new()
+            {
+                ShouldHandle = args => args.Exception switch
+                {
+                    InvalidOperationException => PredicateResult.True,
+                    SocketException => PredicateResult.True,
+                    _ => PredicateResult.False
+                },
+                BaseDelay = TimeSpan.Zero
+            }));
+        }
+
+        var serviceProvider = services.BuildServiceProvider();
+        var api = serviceProvider.GetRequiredService<LibraryApi>();
+
+        // act && assert
+        if (overrideStrategy)
+        {
+            // The library now also handles SocketException.
+            api.Invoking(a => a.ExecuteLibrary(UnstableCall)).Should().NotThrow();
+
+        }
+        else
+        {
+            // Originally, the library strategy only handled InvalidOperationException.
+            api.Invoking(a => a.ExecuteLibrary(UnstableCall)).Should().Throw<SocketException>();
+        }
+
+        void UnstableCall()
+        {
+            if (failFirstCall)
+            {
+                failFirstCall = false;
+
+                // This exception was not originally handled by strategy.
+                throw new SocketException();
+            }
+        }
+    }
+
+    private static void AddLibraryServices(IServiceCollection services)
+    {
+        services.TryAddSingleton<LibraryApi>();
+        services.AddResilienceStrategy("library-strategy", builder => builder.AddRetry(new()
+        {
+            ShouldHandle = args => args.Exception switch
+            {
+                InvalidOperationException => PredicateResult.True,
+                _ => PredicateResult.False
+            }
+        }));
+    }
+
+    public class LibraryApi
+    {
+        private readonly ResilienceStrategy _strategy;
+
+        public LibraryApi(ResilienceStrategyProvider<string> provider) => _strategy = provider.Get("library-strategy");
+
+        public void ExecuteLibrary(Action execute) => _strategy.Execute(execute);
+    }
+}

test/Polly.Extensions.Tests/Issues/IssuesTests.cs

@@ -1,4 +1,4 @@
-namespace Polly.Core.Tests.Issues;
+namespace Polly.Extensions.Tests.Issues;
 
 public partial class IssuesTests
 {