ResilienceStrategyRegistry now uses context to configure the builder

src/Polly.Core.Tests/Registry/ResilienceStrategyRegistryTests.cs

@@ -42,7 +42,7 @@ public void Clear_Ok()
     {
         var registry = new ResilienceStrategyRegistry<string>();
 
-        registry.TryAddBuilder("C", (_, b) => b.AddStrategy(new TestResilienceStrategy()));
+        registry.TryAddBuilder("C", (b, _) => b.AddStrategy(new TestResilienceStrategy()));
 
         registry.TryAdd("A", new TestResilienceStrategy());
         registry.TryAdd("B", new TestResilienceStrategy());
@@ -60,7 +60,7 @@ public void Clear_Generic_Ok()
     {
         var registry = new ResilienceStrategyRegistry<string>();
 
-        registry.TryAddBuilder<string>("C", (_, b) => b.AddStrategy(new TestResilienceStrategy()));
+        registry.TryAddBuilder<string>("C", (b, _) => b.AddStrategy(new TestResilienceStrategy()));
 
         registry.TryAdd("A", new TestResilienceStrategy<string>());
         registry.TryAdd("B", new TestResilienceStrategy<string>());
@@ -107,7 +107,7 @@ public void Remove_Generic_Ok()
     public void RemoveBuilder_Ok()
     {
         var registry = new ResilienceStrategyRegistry<string>();
-        registry.TryAddBuilder("A", (_, b) => b.AddStrategy(new TestResilienceStrategy()));
+        registry.TryAddBuilder("A", (b, _) => b.AddStrategy(new TestResilienceStrategy()));
 
         registry.RemoveBuilder("A").Should().BeTrue();
         registry.RemoveBuilder("A").Should().BeFalse();
@@ -119,7 +119,7 @@ public void RemoveBuilder_Ok()
     public void RemoveBuilder_Generic_Ok()
     {
         var registry = new ResilienceStrategyRegistry<string>();
-        registry.TryAddBuilder<string>("A", (_, b) => b.AddStrategy(new TestResilienceStrategy()));
+        registry.TryAddBuilder<string>("A", (b, _) => b.AddStrategy(new TestResilienceStrategy()));
 
         registry.RemoveBuilder<string>("A").Should().BeTrue();
         registry.RemoveBuilder<string>("A").Should().BeFalse();
@@ -133,7 +133,7 @@ public void GetStrategy_BuilderMultiInstance_EnsureMultipleInstances()
         var builderName = "A";
         var registry = CreateRegistry();
         var strategies = new HashSet<ResilienceStrategy>();
-        registry.TryAddBuilder(StrategyId.Create(builderName), (_, builder) => builder.AddStrategy(new TestResilienceStrategy()));
+        registry.TryAddBuilder(StrategyId.Create(builderName), (builder, _) => builder.AddStrategy(new TestResilienceStrategy()));
 
         for (int i = 0; i < 100; i++)
         {
@@ -154,7 +154,7 @@ public void GetStrategy_GenericBuilderMultiInstance_EnsureMultipleInstances()
         var builderName = "A";
         var registry = CreateRegistry();
         var strategies = new HashSet<ResilienceStrategy<string>>();
-        registry.TryAddBuilder<string>(StrategyId.Create(builderName), (_, builder) => builder.AddStrategy(new TestResilienceStrategy()));
+        registry.TryAddBuilder<string>(StrategyId.Create(builderName), (builder, _) => builder.AddStrategy(new TestResilienceStrategy()));
 
         for (int i = 0; i < 100; i++)
         {
@@ -176,10 +176,10 @@ public void AddBuilder_GetStrategy_EnsureCalled()
         _callback = _ => activatorCalls++;
         var registry = CreateRegistry();
         var called = 0;
-        registry.TryAddBuilder(StrategyId.Create("A"), (key, builder) =>
+        registry.TryAddBuilder(StrategyId.Create("A"), (builder, context) =>
         {
             builder.AddStrategy(new TestResilienceStrategy());
-            builder.Properties.Set(StrategyId.ResilienceKey, key);
+            builder.Properties.Set(StrategyId.ResilienceKey, context.StrategyKey);
             called++;
         });
 
@@ -205,10 +205,10 @@ public void AddBuilder_GenericGetStrategy_EnsureCalled()
         _callback = _ => activatorCalls++;
         var registry = CreateRegistry();
         var called = 0;
-        registry.TryAddBuilder<string>(StrategyId.Create("A"), (key, builder) =>
+        registry.TryAddBuilder<string>(StrategyId.Create("A"), (builder, context) =>
         {
             builder.AddStrategy(new TestResilienceStrategy());
-            builder.Properties.Set(StrategyId.ResilienceKey, key);
+            builder.Properties.Set(StrategyId.ResilienceKey, context.StrategyKey);
             called++;
         });
 
@@ -235,8 +235,10 @@ public void AddBuilder_EnsureStrategyKey()
 
         var called = false;
         var registry = CreateRegistry();
-        registry.TryAddBuilder(StrategyId.Create("A"), (_, builder) =>
+        registry.TryAddBuilder(StrategyId.Create("A"), (builder, context) =>
         {
+            context.BuilderName.Should().Be("A");
+            context.StrategyKeyString.Should().Be("Instance1");
             builder.AddStrategy(new TestResilienceStrategy());
             builder.BuilderName.Should().Be("A");
             builder.Properties.TryGetValue(TelemetryUtil.StrategyKey, out var val).Should().BeTrue();
@@ -252,8 +254,8 @@ public void AddBuilder_EnsureStrategyKey()
     public void AddBuilder_MultipleGeneric_EnsureDistinctInstances()
     {
         var registry = CreateRegistry();
-        registry.TryAddBuilder<string>(StrategyId.Create("A"), (_, builder) => builder.AddStrategy(new TestResilienceStrategy()));
-        registry.TryAddBuilder<int>(StrategyId.Create("A"), (_, builder) => builder.AddStrategy(new TestResilienceStrategy()));
+        registry.TryAddBuilder<string>(StrategyId.Create("A"), (builder, _) => builder.AddStrategy(new TestResilienceStrategy()));
+        registry.TryAddBuilder<int>(StrategyId.Create("A"), (builder, _) => builder.AddStrategy(new TestResilienceStrategy()));
 
         registry.Get<string>(StrategyId.Create("A", "Instance1")).Should().BeSameAs(registry.Get<string>(StrategyId.Create("A", "Instance1")));
         registry.Get<int>(StrategyId.Create("A", "Instance1")).Should().BeSameAs(registry.Get<int>(StrategyId.Create("A", "Instance1")));
@@ -267,7 +269,7 @@ public void AddBuilder_Generic_EnsureStrategyKey()
 
         var called = false;
         var registry = CreateRegistry();
-        registry.TryAddBuilder<string>(StrategyId.Create("A"), (_, builder) =>
+        registry.TryAddBuilder<string>(StrategyId.Create("A"), (builder, _) =>
         {
             builder.AddStrategy(new TestResilienceStrategy());
             builder.BuilderName.Should().Be("A");

src/Polly.Core/Registry/ConfigureBuilderContext.cs

@@ -0,0 +1,37 @@
+namespace Polly.Registry;
+
+/// <summary>
+/// The context used by <see cref="ResilienceStrategyRegistry{TKey}"/>.
+/// </summary>
+/// <typeparam name="TKey">The type of the key.</typeparam>
+public class ConfigureBuilderContext<TKey>
+    where TKey : notnull
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ConfigureBuilderContext{TKey}"/> class.
+    /// </summary>
+    /// <param name="strategyKey">The strategy key.</param>
+    /// <param name="builderName">The builder name.</param>
+    /// <param name="strategyKeyString">The strategy key as string.</param>
+    public ConfigureBuilderContext(TKey strategyKey, string builderName, string strategyKeyString)
+    {
+        StrategyKey = strategyKey;
+        BuilderName = builderName;
+        StrategyKeyString = strategyKeyString;
+    }
+
+    /// <summary>
+    /// Gets the strategy key for the strategy being created.
+    /// </summary>
+    public TKey StrategyKey { get; }
+
+    /// <summary>
+    /// Gets the builder name for the builder being used to create the strategy.
+    /// </summary>
+    public string BuilderName { get; }
+
+    /// <summary>
+    /// Gets the string representation of strategy key for the strategy being created.
+    /// </summary>
+    public string StrategyKeyString { get; }
+}

src/Polly.Core/Registry/ResilienceStrategyRegistry.TResult.cs

@@ -1,5 +1,4 @@
 using System.Diagnostics.CodeAnalysis;
-using Polly.Telemetry;
 
 namespace Polly.Registry;
 
@@ -9,7 +8,7 @@ public sealed partial class ResilienceStrategyRegistry<TKey> : ResilienceStrateg
     private sealed class GenericRegistry<TResult>
     {
         private readonly Func<ResilienceStrategyBuilder<TResult>> _activator;
-        private readonly ConcurrentDictionary<TKey, Action<TKey, ResilienceStrategyBuilder<TResult>>> _builders;
+        private readonly ConcurrentDictionary<TKey, Action<ResilienceStrategyBuilder<TResult>, ConfigureBuilderContext<TKey>>> _builders;
         private readonly ConcurrentDictionary<TKey, ResilienceStrategy<TResult>> _strategies;
 
         private readonly Func<TKey, string> _strategyKeyFormatter;
@@ -23,7 +22,7 @@ public GenericRegistry(
             Func<TKey, string> builderNameFormatter)
         {
             _activator = activator;
-            _builders = new ConcurrentDictionary<TKey, Action<TKey, ResilienceStrategyBuilder<TResult>>>(builderComparer);
+            _builders = new ConcurrentDictionary<TKey, Action<ResilienceStrategyBuilder<TResult>, ConfigureBuilderContext<TKey>>>(builderComparer);
             _strategies = new ConcurrentDictionary<TKey, ResilienceStrategy<TResult>>(strategyComparer);
             _strategyKeyFormatter = strategyKeyFormatter;
             _builderNameFormatter = builderNameFormatter;
@@ -44,11 +43,8 @@ public bool TryGet(TKey key, [NotNullWhen(true)] out ResilienceStrategy<TResult>
             {
                 strategy = _strategies.GetOrAdd(key, key =>
                 {
-                    var builder = _activator();
-                    builder.BuilderName = _builderNameFormatter(key);
-                    builder.Properties.Set(TelemetryUtil.StrategyKey, _strategyKeyFormatter(key));
-                    configure(key, builder);
-                    return builder.Build();
+                    var context = new ConfigureBuilderContext<TKey>(key, _builderNameFormatter(key), _strategyKeyFormatter(key));
+                    return _strategies.GetOrAdd(key, key => new ResilienceStrategy<TResult>(CreateStrategy(_activator, context, configure)));
                 });
 
                 return true;
@@ -58,7 +54,7 @@ public bool TryGet(TKey key, [NotNullWhen(true)] out ResilienceStrategy<TResult>
             return false;
         }
 
-        public bool TryAddBuilder(TKey key, Action<TKey, ResilienceStrategyBuilder<TResult>> configure) => _builders.TryAdd(key, configure);
+        public bool TryAddBuilder(TKey key, Action<ResilienceStrategyBuilder<TResult>, ConfigureBuilderContext<TKey>> configure) => _builders.TryAdd(key, configure);
 
         public bool RemoveBuilder(TKey key) => _builders.TryRemove(key, out _);
 

src/Polly.Core/Registry/ResilienceStrategyRegistry.cs

@@ -1,5 +1,6 @@
 using System.ComponentModel.DataAnnotations;
 using System.Diagnostics.CodeAnalysis;
+using Polly.Strategy;
 using Polly.Telemetry;
 
 namespace Polly.Registry;
@@ -20,7 +21,7 @@ public sealed partial class ResilienceStrategyRegistry<TKey> : ResilienceStrateg
     where TKey : notnull
 {
     private readonly Func<ResilienceStrategyBuilder> _activator;
-    private readonly ConcurrentDictionary<TKey, Action<TKey, ResilienceStrategyBuilder>> _builders;
+    private readonly ConcurrentDictionary<TKey, Action<ResilienceStrategyBuilder, ConfigureBuilderContext<TKey>>> _builders;
     private readonly ConcurrentDictionary<TKey, ResilienceStrategy> _strategies;
     private readonly ConcurrentDictionary<Type, object> _genericRegistry = new();
 
@@ -50,7 +51,7 @@ public ResilienceStrategyRegistry(ResilienceStrategyRegistryOptions<TKey> option
         ValidationHelper.ValidateObject(options, "The resilience strategy registry options are invalid.");
 
         _activator = options.BuilderFactory;
-        _builders = new ConcurrentDictionary<TKey, Action<TKey, ResilienceStrategyBuilder>>(options.BuilderComparer);
+        _builders = new ConcurrentDictionary<TKey, Action<ResilienceStrategyBuilder, ConfigureBuilderContext<TKey>>>(options.BuilderComparer);
         _strategies = new ConcurrentDictionary<TKey, ResilienceStrategy>(options.StrategyComparer);
         _strategyKeyFormatter = options.StrategyKeyFormatter;
         _builderNameFormatter = options.BuilderNameFormatter;
@@ -118,15 +119,8 @@ public override bool TryGet(TKey key, [NotNullWhen(true)] out ResilienceStrategy
 
         if (_builders.TryGetValue(key, out var configure))
         {
-            strategy = _strategies.GetOrAdd(key, key =>
-            {
-                var builder = _activator();
-                builder.BuilderName = _builderNameFormatter(key);
-                builder.Properties.Set(TelemetryUtil.StrategyKey, _strategyKeyFormatter(key));
-                configure(key, builder);
-                return builder.Build();
-            });
-
+            var context = new ConfigureBuilderContext<TKey>(key, _builderNameFormatter(key), _strategyKeyFormatter(key));
+            strategy = _strategies.GetOrAdd(key, key => CreateStrategy(_activator, context, configure));
             return true;
         }
 
@@ -144,7 +138,7 @@ public override bool TryGet(TKey key, [NotNullWhen(true)] out ResilienceStrategy
     /// Use this method when you want to create the strategy on-demand when it's first accessed.
     /// </remarks>
     /// <exception cref="ArgumentNullException">Thrown when <paramref name="configure"/> is <see langword="null"/>.</exception>
-    public bool TryAddBuilder(TKey key, Action<TKey, ResilienceStrategyBuilder> configure)
+    public bool TryAddBuilder(TKey key, Action<ResilienceStrategyBuilder, ConfigureBuilderContext<TKey>> configure)
     {
         Guard.NotNull(configure);
 
@@ -162,7 +156,7 @@ public bool TryAddBuilder(TKey key, Action<TKey, ResilienceStrategyBuilder> conf
     /// Use this method when you want to create the strategy on-demand when it's first accessed.
     /// </remarks>
     /// <exception cref="ArgumentNullException">Thrown when <paramref name="configure"/> is <see langword="null"/>.</exception>
-    public bool TryAddBuilder<TResult>(TKey key, Action<TKey, ResilienceStrategyBuilder<TResult>> configure)
+    public bool TryAddBuilder<TResult>(TKey key, Action<ResilienceStrategyBuilder<TResult>, ConfigureBuilderContext<TKey>> configure)
     {
         Guard.NotNull(configure);
 
@@ -201,6 +195,19 @@ public bool TryAddBuilder<TResult>(TKey key, Action<TKey, ResilienceStrategyBuil
     /// </remarks>
     public void Clear<TResult>() => GetGenericRegistry<TResult>().Clear();
 
+    private static ResilienceStrategy CreateStrategy<TBuilder>(
+        Func<TBuilder> activator,
+        ConfigureBuilderContext<TKey> context,
+        Action<TBuilder, ConfigureBuilderContext<TKey>> configure)
+        where TBuilder : ResilienceStrategyBuilderBase
+    {
+        var builder = activator();
+        builder.BuilderName = context.BuilderName;
+        builder.Properties.Set(TelemetryUtil.StrategyKey, context.StrategyKeyString);
+        configure(builder, context);
+        return builder.BuildStrategy();
+    }
+
     private GenericRegistry<TResult> GetGenericRegistry<TResult>()
     {
         if (_genericRegistry.TryGetValue(typeof(TResult), out var genericRegistry))

src/Polly.Extensions.Tests/DependencyInjection/PollyServiceCollectionExtensionTests.cs

@@ -95,7 +95,7 @@ public void AddResilienceStrategy_EnsureContextFilled(bool generic)
         {
             _services.AddResilienceStrategy<string, string>(Key, (builder, context) =>
             {
-                context.Key.Should().Be(Key);
+                context.StrategyKey.Should().Be(Key);
                 builder.Should().NotBeNull();
                 context.ServiceProvider.Should().NotBeNull();
                 builder.AddStrategy(new TestStrategy());
@@ -108,7 +108,7 @@ public void AddResilienceStrategy_EnsureContextFilled(bool generic)
         {
             _services.AddResilienceStrategy(Key, (builder, context) =>
             {
-                context.Key.Should().Be(Key);
+                context.StrategyKey.Should().Be(Key);
                 builder.Should().NotBeNull();
                 context.ServiceProvider.Should().NotBeNull();
                 builder.AddStrategy(new TestStrategy());

src/Polly.Extensions/DependencyInjection/AddResilienceStrategyContext.cs

@@ -1,22 +1,16 @@
+using Polly.Registry;
+
 namespace Polly.Extensions.DependencyInjection;
 
 /// <summary>
 /// Represents the context for adding a resilience strategy with the specified key.
 /// </summary>
 /// <typeparam name="TKey">The type of the key used to identify the resilience strategy.</typeparam>
-public sealed class AddResilienceStrategyContext<TKey>
+public sealed class AddResilienceStrategyContext<TKey> : ConfigureBuilderContext<TKey>
     where TKey : notnull
 {
-    internal AddResilienceStrategyContext(TKey key, IServiceProvider serviceProvider)
-    {
-        Key = key;
-        ServiceProvider = serviceProvider;
-    }
-
-    /// <summary>
-    /// Gets the key used to identify the resilience strategy.
-    /// </summary>
-    public TKey Key { get; }
+    internal AddResilienceStrategyContext(ConfigureBuilderContext<TKey> context, IServiceProvider serviceProvider)
+        : base(context.StrategyKey, context.BuilderName, context.StrategyKeyString) => ServiceProvider = serviceProvider;
 
     /// <summary>
     /// Gets the <see cref="IServiceProvider"/> that provides access to the dependency injection container.

src/Polly.Extensions/DependencyInjection/PollyServiceCollectionExtensions.cs

@@ -80,9 +80,9 @@ public static IServiceCollection AddResilienceStrategy<TKey, TResult>(
                 {
                     // the last added builder with the same key wins, this allows overriding the builders
                     registry.RemoveBuilder<TResult>(key);
-                    registry.TryAddBuilder<TResult>(key, (key, builder) =>
+                    registry.TryAddBuilder<TResult>(key, (builder, context) =>
                     {
-                        configure(builder, new AddResilienceStrategyContext<TKey>(key, serviceProvider));
+                        configure(builder, new AddResilienceStrategyContext<TKey>(context, serviceProvider));
                     });
                 });
             });
@@ -151,9 +151,9 @@ public static IServiceCollection AddResilienceStrategy<TKey>(
                 {
                     // the last added builder with the same key wins, this allows overriding the builders
                     registry.RemoveBuilder(key);
-                    registry.TryAddBuilder(key, (key, builder) =>
+                    registry.TryAddBuilder(key, (builder, context) =>
                     {
-                        configure(builder, new AddResilienceStrategyContext<TKey>(key, serviceProvider));
+                        configure(builder, new AddResilienceStrategyContext<TKey>(context, serviceProvider));
                     });
                 });
             });