Add API allowing to disable retries for a given list of HTTP methods (#…

…5634)

* Fixes #5248

Adds APIs allowing to disable automatic retries for a given list of HTTP methods

* Fixes #5248

Adds a check ensuring options.ShouldHandle is not null

src/Libraries/Microsoft.Extensions.Http.Resilience/Polly/HttpRetryStrategyOptionsExtensions.cs

@@ -0,0 +1,66 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Diagnostics.CodeAnalysis;
+using System.Linq;
+using System.Net.Http;
+using System.Threading.Tasks;
+using Microsoft.Shared.DiagnosticIds;
+using Microsoft.Shared.Diagnostics;
+using Polly;
+
+namespace Microsoft.Extensions.Http.Resilience;
+
+/// <summary>
+/// Extensions for <see cref="HttpRetryStrategyOptions"/>.
+/// </summary>
+[Experimental(diagnosticId: DiagnosticIds.Experiments.Resilience, UrlFormat = DiagnosticIds.UrlFormat)]
+public static class HttpRetryStrategyOptionsExtensions
+{
+#if !NET8_0_OR_GREATER
+    private static readonly HttpMethod _connect = new("CONNECT");
+    private static readonly HttpMethod _patch = new("PATCH");
+#endif
+
+    /// <summary>
+    /// Disables retry attempts for POST, PATCH, PUT, DELETE, and CONNECT HTTP methods.
+    /// </summary>
+    /// <param name="options">The retry strategy options.</param>
+    public static void DisableForUnsafeHttpMethods(this HttpRetryStrategyOptions options)
+    {
+        options.DisableFor(
+            HttpMethod.Delete, HttpMethod.Post, HttpMethod.Put,
+#if !NET8_0_OR_GREATER
+            _connect, _patch);
+#else
+            HttpMethod.Connect, HttpMethod.Patch);
+#endif
+    }
+
+    /// <summary>
+    /// Disables retry attempts for the given list of HTTP methods.
+    /// </summary>
+    /// <param name="options">The retry strategy options.</param>
+    /// <param name="methods">The list of HTTP methods.</param>
+    public static void DisableFor(this HttpRetryStrategyOptions options, params HttpMethod[] methods)
+    {
+        _ = Throw.IfNullOrEmpty(methods);
+
+        var shouldHandle = Throw.IfNullOrMemberNull(options, options?.ShouldHandle);
+
+        options.ShouldHandle = async args =>
+        {
+            var result = await shouldHandle(args).ConfigureAwait(args.Context.ContinueOnCapturedContext);
+
+            if (result &&
+                args.Outcome.Result is HttpResponseMessage response &&
+                response.RequestMessage is HttpRequestMessage request)
+            {
+                return !methods.Contains(request.Method);
+            }
+
+            return result;
+        };
+    }
+}
+

test/Libraries/Microsoft.Extensions.Http.Resilience.Tests/Polly/HttpRetryStrategyOptionsExtensionsTests.cs

@@ -0,0 +1,115 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Net.Http;
+using System.Threading.Tasks;
+using Polly;
+using Polly.Retry;
+using Xunit;
+
+namespace Microsoft.Extensions.Http.Resilience.Test.Polly;
+
+public class HttpRetryStrategyOptionsExtensionsTests
+{
+    [Fact]
+    public void DisableFor_RetryOptionsIsNull_Throws()
+    {
+        Assert.Throws<ArgumentNullException>(() => ((HttpRetryStrategyOptions)null!).DisableFor(HttpMethod.Get));
+    }
+
+    [Fact]
+    public void DisableFor_HttpMethodsIsNull_Throws()
+    {
+        Assert.Throws<ArgumentNullException>(() => new HttpRetryStrategyOptions().DisableFor(null!));
+    }
+
+    [Fact]
+    public void DisableFor_HttpMethodsIsEmptry_Throws()
+    {
+        Assert.Throws<ArgumentException>(() => new HttpRetryStrategyOptions().DisableFor([]));
+    }
+
+    [Fact]
+    public void DisableFor_ShouldHandleIsNull_Throws()
+    {
+        var options = new HttpRetryStrategyOptions { ShouldHandle = null! };
+        Assert.Throws<ArgumentException>(() => options.DisableFor(HttpMethod.Get));
+    }
+
+    [Theory]
+    [InlineData("POST", false)]
+    [InlineData("DELETE", false)]
+    [InlineData("GET", true)]
+    public async Task DisableFor_PositiveScenario(string httpMethod, bool shouldHandle)
+    {
+        var options = new HttpRetryStrategyOptions { ShouldHandle = _ => PredicateResult.True() };
+        options.DisableFor(HttpMethod.Post, HttpMethod.Delete);
+
+        using var request = new HttpRequestMessage { Method = new HttpMethod(httpMethod) };
+        using var response = new HttpResponseMessage { RequestMessage = request };
+
+        Assert.Equal(shouldHandle, await options.ShouldHandle(CreatePredicateArguments(response)));
+    }
+
+    [Fact]
+    public async Task DisableFor_RespectsOriginalShouldHandlePredicate()
+    {
+        var options = new HttpRetryStrategyOptions { ShouldHandle = _ => PredicateResult.False() };
+        options.DisableFor(HttpMethod.Post);
+
+        using var request = new HttpRequestMessage { Method = HttpMethod.Get };
+        using var response = new HttpResponseMessage { RequestMessage = request };
+
+        Assert.False(await options.ShouldHandle(CreatePredicateArguments(response)));
+    }
+
+    [Fact]
+    public async Task DisableFor_ResponseMessageIsNull_DoesNotDisableRetries()
+    {
+        var options = new HttpRetryStrategyOptions { ShouldHandle = _ => PredicateResult.True() };
+        options.DisableFor(HttpMethod.Post);
+
+        Assert.True(await options.ShouldHandle(CreatePredicateArguments(null)));
+    }
+
+    [Fact]
+    public async Task DisableFor_RequestMessageIsNull_DoesNotDisableRetries()
+    {
+        var options = new HttpRetryStrategyOptions { ShouldHandle = _ => PredicateResult.True() };
+        options.DisableFor(HttpMethod.Post);
+
+        using var response = new HttpResponseMessage { RequestMessage = null };
+
+        Assert.True(await options.ShouldHandle(CreatePredicateArguments(response)));
+    }
+
+    [Theory]
+    [InlineData("POST", false)]
+    [InlineData("DELETE", false)]
+    [InlineData("PUT", false)]
+    [InlineData("PATCH", false)]
+    [InlineData("CONNECT", false)]
+    [InlineData("GET", true)]
+    [InlineData("HEAD", true)]
+    [InlineData("TRACE", true)]
+    [InlineData("OPTIONS", true)]
+    public async Task DisableForUnsafeHttpMethods_PositiveScenario(string httpMethod, bool shouldHandle)
+    {
+        var options = new HttpRetryStrategyOptions { ShouldHandle = _ => PredicateResult.True() };
+        options.DisableForUnsafeHttpMethods();
+
+        using var request = new HttpRequestMessage { Method = new HttpMethod(httpMethod) };
+        using var response = new HttpResponseMessage { RequestMessage = request };
+
+        Assert.Equal(shouldHandle, await options.ShouldHandle(CreatePredicateArguments(response)));
+    }
+
+    private static RetryPredicateArguments<HttpResponseMessage> CreatePredicateArguments(HttpResponseMessage? response)
+    {
+        return new RetryPredicateArguments<HttpResponseMessage>(
+            ResilienceContextPool.Shared.Get(),
+            Outcome.FromResult(response),
+            attemptNumber: 1);
+    }
+}