Allow adding a resilience strategy without explicit options

src/Polly.Core/PublicAPI.Unshipped.txt

@@ -1 +1,4 @@
 #nullable enable
+static Polly.ResiliencePipelineBuilderExtensions.AddStrategy(this Polly.ResiliencePipelineBuilder! builder, System.Func<Polly.StrategyBuilderContext!, Polly.ResilienceStrategy<object!>!>! factory) -> Polly.ResiliencePipelineBuilder!
+static Polly.ResiliencePipelineBuilderExtensions.AddStrategy<TBuilder>(this TBuilder! builder, System.Func<Polly.StrategyBuilderContext!, Polly.ResilienceStrategy!>! factory) -> TBuilder!
+static Polly.ResiliencePipelineBuilderExtensions.AddStrategy<TResult>(this Polly.ResiliencePipelineBuilder<TResult>! builder, System.Func<Polly.StrategyBuilderContext!, Polly.ResilienceStrategy<TResult>!>! factory) -> Polly.ResiliencePipelineBuilder<TResult>!

src/Polly.Core/ResiliencePipelineBuilderExtensions.cs

@@ -60,13 +60,16 @@ public static ResiliencePipelineBuilder<TResult> AddPipeline<TResult>(this Resil
     /// <typeparam name="TBuilder">The builder type.</typeparam>
     /// <param name="builder">The builder instance.</param>
     /// <param name="factory">The factory that creates a resilience strategy.</param>
-    /// <param name="options">The options associated with the strategy. If none are provided the default instance of <see cref="ResilienceStrategyOptions"/> is created.</param>
+    /// <param name="options">The options associated with the strategy.</param>
     /// <returns>The same builder instance.</returns>
     /// <exception cref="ArgumentNullException">Thrown when <paramref name="builder"/>, <paramref name="factory"/> or <paramref name="options"/> is <see langword="null"/>.</exception>
     /// <exception cref="InvalidOperationException">Thrown when this builder was already used to create a pipeline. The builder cannot be modified after it has been used.</exception>
     /// <exception cref="ValidationException">Thrown when <paramref name="options"/> is invalid.</exception>
     [RequiresUnreferencedCode(Constants.OptionsValidation)]
-    public static TBuilder AddStrategy<TBuilder>(this TBuilder builder, Func<StrategyBuilderContext, ResilienceStrategy> factory, ResilienceStrategyOptions options)
+    public static TBuilder AddStrategy<TBuilder>(
+        this TBuilder builder,
+        Func<StrategyBuilderContext, ResilienceStrategy> factory,
+        ResilienceStrategyOptions options)
         where TBuilder : ResiliencePipelineBuilderBase
     {
         Guard.NotNull(builder);
@@ -82,14 +85,15 @@ public static TBuilder AddStrategy<TBuilder>(this TBuilder builder, Func<Strateg
     /// </summary>
     /// <param name="builder">The builder instance.</param>
     /// <param name="factory">The factory that creates a resilience strategy.</param>
-    /// <param name="options">The options associated with the strategy. If none are provided the default instance of <see cref="ResilienceStrategyOptions"/> is created.</param>
+    /// <param name="options">The options associated with the strategy.</param>
     /// <returns>The same builder instance.</returns>
     /// <exception cref="ArgumentNullException">Thrown when <paramref name="builder"/>, <paramref name="factory"/> or <paramref name="options"/> is <see langword="null"/>.</exception>
     /// <exception cref="InvalidOperationException">Thrown when this builder was already used to create a pipeline. The builder cannot be modified after it has been used.</exception>
     /// <exception cref="ValidationException">Thrown when <paramref name="options"/> is invalid.</exception>
     [RequiresUnreferencedCode(Constants.OptionsValidation)]
     public static ResiliencePipelineBuilder AddStrategy(
-        this ResiliencePipelineBuilder builder, Func<StrategyBuilderContext, ResilienceStrategy<object>> factory,
+        this ResiliencePipelineBuilder builder,
+        Func<StrategyBuilderContext, ResilienceStrategy<object>> factory,
         ResilienceStrategyOptions options)
     {
         Guard.NotNull(builder);
@@ -106,14 +110,15 @@ public static ResiliencePipelineBuilder AddStrategy(
     /// <typeparam name="TResult">The type of the result.</typeparam>
     /// <param name="builder">The builder instance.</param>
     /// <param name="factory">The factory that creates a resilience strategy.</param>
-    /// <param name="options">The options associated with the strategy. If none are provided the default instance of <see cref="ResilienceStrategyOptions"/> is created.</param>
+    /// <param name="options">The options associated with the strategy.</param>
     /// <returns>The same builder instance.</returns>
     /// <exception cref="ArgumentNullException">Thrown when <paramref name="builder"/>, <paramref name="factory"/> or <paramref name="options"/> is <see langword="null"/>.</exception>
     /// <exception cref="InvalidOperationException">Thrown when this builder was already used to create a pipeline. The builder cannot be modified after it has been used.</exception>
     /// <exception cref="ValidationException">Thrown when <paramref name="options"/> is invalid.</exception>
     [RequiresUnreferencedCode(Constants.OptionsValidation)]
     public static ResiliencePipelineBuilder<TResult> AddStrategy<TResult>(
-        this ResiliencePipelineBuilder<TResult> builder, Func<StrategyBuilderContext, ResilienceStrategy<TResult>> factory,
+        this ResiliencePipelineBuilder<TResult> builder,
+        Func<StrategyBuilderContext, ResilienceStrategy<TResult>> factory,
         ResilienceStrategyOptions options)
     {
         Guard.NotNull(builder);
@@ -124,6 +129,78 @@ public static ResiliencePipelineBuilder<TResult> AddStrategy<TResult>(
         return builder;
     }
 
+    /// <summary>
+    /// Adds a reactive resilience strategy to the builder.
+    /// </summary>
+    /// <typeparam name="TBuilder">The builder type.</typeparam>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="factory">The strategy factory.</param>
+    /// <returns>The same builder instance.</returns>
+    /// <exception cref="ArgumentNullException">Thrown when <paramref name="builder"/> or <paramref name="factory"/> is <see langword="null"/>.</exception>
+    /// <exception cref="InvalidOperationException">Thrown when this builder was already used to create a pipeline. The builder cannot be modified after it has been used.</exception>
+    [DynamicDependency(DynamicallyAccessedMemberTypes.All, typeof(EmptyOptions))]
+    [UnconditionalSuppressMessage(
+        "Trimming",
+        "IL2026:Members annotated with 'RequiresUnreferencedCodeAttribute' require dynamic access otherwise can break functionality when trimming application code",
+        Justification = "All options members preserved for the empty options.")]
+    public static TBuilder AddStrategy<TBuilder>(
+        this TBuilder builder,
+        Func<StrategyBuilderContext, ResilienceStrategy> factory)
+        where TBuilder : ResiliencePipelineBuilderBase
+    {
+        Guard.NotNull(builder);
+        Guard.NotNull(factory);
+
+        return builder.AddStrategy(factory, EmptyOptions.Instance);
+    }
+
+    /// <summary>
+    /// Adds a proactive resilience strategy to the builder.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="factory">The strategy instance.</param>
+    /// <returns>The same builder instance.</returns>
+    /// <exception cref="ArgumentNullException">Thrown when <paramref name="builder"/> or <paramref name="factory"/> is <see langword="null"/>.</exception>
+    /// <exception cref="InvalidOperationException">Thrown when this builder was already used to create a pipeline. The builder cannot be modified after it has been used.</exception>
+    [DynamicDependency(DynamicallyAccessedMemberTypes.All, typeof(EmptyOptions))]
+    [UnconditionalSuppressMessage(
+        "Trimming",
+        "IL2026:Members annotated with 'RequiresUnreferencedCodeAttribute' require dynamic access otherwise can break functionality when trimming application code",
+        Justification = "All options members preserved for the empty options.")]
+    public static ResiliencePipelineBuilder AddStrategy(
+        this ResiliencePipelineBuilder builder,
+        Func<StrategyBuilderContext, ResilienceStrategy<object>> factory)
+    {
+        Guard.NotNull(builder);
+        Guard.NotNull(factory);
+
+        return builder.AddStrategy(factory, EmptyOptions.Instance);
+    }
+
+    /// <summary>
+    /// Adds a reactive resilience strategy to the builder.
+    /// </summary>
+    /// <typeparam name="TResult">The result type.</typeparam>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="factory">The strategy instance.</param>
+    /// <returns>The same builder instance.</returns>
+    /// <exception cref="ArgumentNullException">Thrown when <paramref name="builder"/> or <paramref name="factory"/> is <see langword="null"/>.</exception>
+    /// <exception cref="InvalidOperationException">Thrown when this builder was already used to create a pipeline. The builder cannot be modified after it has been used.</exception>
+    [DynamicDependency(DynamicallyAccessedMemberTypes.All, typeof(EmptyOptions))]
+    [UnconditionalSuppressMessage(
+        "Trimming",
+        "IL2026:Members annotated with 'RequiresUnreferencedCodeAttribute' require dynamic access otherwise can break functionality when trimming application code",
+        Justification = "All options members preserved for the empty options.")]
+    public static ResiliencePipelineBuilder<TResult> AddStrategy<TResult>(
+        this ResiliencePipelineBuilder<TResult> builder,
+        Func<StrategyBuilderContext, ResilienceStrategy<TResult>> factory)
+    {
+        Guard.NotNull(builder);
+        Guard.NotNull(factory);
+
+        return builder.AddStrategy(factory, EmptyOptions.Instance);
+    }
+
     internal sealed class EmptyOptions : ResilienceStrategyOptions
     {
         public static readonly EmptyOptions Instance = new();

test/Polly.Core.Tests/GenericResiliencePipelineBuilderTests.cs

@@ -1,5 +1,6 @@
 using Microsoft.Extensions.Time.Testing;
 using NSubstitute;
+using Polly.Testing;
 using Polly.Utils.Pipeline;
 
 namespace Polly.Core.Tests;
@@ -63,4 +64,19 @@ public void AddGenericStrategy_Ok()
             .Should()
             .Be(strategy);
     }
+
+    [Fact]
+    public void AddStrategy_ExplicitInstance_Ok()
+    {
+        var builder = new ResiliencePipelineBuilder<string>();
+        var strategy = Substitute.For<ResilienceStrategy<string>>();
+
+        builder.AddStrategy(_ => strategy);
+
+        builder
+            .Build()
+            .GetPipelineDescriptor()
+            .FirstStrategy.StrategyInstance.Should()
+            .BeSameAs(strategy);
+    }
 }

test/Polly.Core.Tests/ResiliencePipelineBuilderTests.cs

@@ -114,6 +114,36 @@ public void AddPipeline_Multiple_Ok()
         executions.Should().HaveCount(7);
     }
 
+    [Fact]
+    public void AddStrategy_ExplicitProactiveInstance_Ok()
+    {
+        var builder = new ResiliencePipelineBuilder();
+        var strategy = new TestResilienceStrategy();
+
+        builder.AddStrategy(_ => strategy);
+
+        builder
+            .Build()
+            .GetPipelineDescriptor()
+            .FirstStrategy.StrategyInstance.Should()
+            .BeSameAs(strategy);
+    }
+
+    [Fact]
+    public void AddStrategy_ExplicitReactiveInstance_Ok()
+    {
+        var builder = new ResiliencePipelineBuilder();
+        var strategy = Substitute.For<ResilienceStrategy<object>>();
+
+        builder.AddStrategy(_ => strategy);
+
+        builder
+            .Build()
+            .GetPipelineDescriptor()
+            .FirstStrategy.StrategyInstance.Should()
+            .BeSameAs(strategy);
+    }
+
     [Fact]
     public void Validator_Ok()
     {