Improve endpoint metadata debugging (dotnet#48207)

Co-authored-by: Sean Farrow <sean.farrow@seanfarrow.co.uk>

src/Http/Http.Abstractions/src/Routing/Endpoint.cs

@@ -1,11 +1,14 @@
 // 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;
+
 namespace Microsoft.AspNetCore.Http;
 
 /// <summary>
 /// Represents a logical endpoint in an application.
 /// </summary>
+[DebuggerDisplay("{ToString(),nq}")]
 public class Endpoint
 {
     /// <summary>

src/Http/Http.Abstractions/src/Routing/EndpointMetadataCollection.cs

@@ -3,6 +3,7 @@
 
 using System.Collections;
 using System.Collections.Concurrent;
+using System.Diagnostics;
 using System.Linq;
 using System.Runtime.CompilerServices;
 
@@ -16,6 +17,8 @@ namespace Microsoft.AspNetCore.Http;
 /// of arbitrary types. The metadata items are stored as an ordered collection with
 /// items arranged in ascending order of precedence.
 /// </remarks>
+[DebuggerTypeProxy(typeof(EndpointMetadataCollectionDebugView))]
+[DebuggerDisplay("Count = {Count}")]
 public sealed class EndpointMetadataCollection : IReadOnlyList<object>
 {
     /// <summary>
@@ -215,4 +218,27 @@ public void Reset()
             _current = null;
         }
     }
+
+    private sealed class EndpointMetadataCollectionDebugView
+    {
+        private readonly EndpointMetadataCollection _collection;
+
+        public EndpointMetadataCollectionDebugView(EndpointMetadataCollection collection)
+        {
+            ArgumentNullException.ThrowIfNull(collection);
+
+            _collection = collection;
+        }
+
+        [DebuggerBrowsable(DebuggerBrowsableState.RootHidden)]
+        public object[] Items
+        {
+            get
+            {
+                var items = new object[_collection.Count];
+                _collection._items.CopyTo(items, 0);
+                return items;
+            }
+        }
+    }
 }

src/Http/Http.Extensions/src/EndpointDescriptionAttribute.cs

@@ -1,6 +1,7 @@
 // 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;
 using Microsoft.AspNetCore.Http.Metadata;
 
 namespace Microsoft.AspNetCore.Http;
@@ -13,6 +14,7 @@ namespace Microsoft.AspNetCore.Http;
 /// can be used to annotate endpoints with detailed, multiline descriptors of their behavior.
 /// </remarks>
 [AttributeUsage(AttributeTargets.Method, Inherited = false, AllowMultiple = false)]
+[DebuggerDisplay("{ToString(),nq}")]
 public sealed class EndpointDescriptionAttribute : Attribute, IEndpointDescriptionMetadata
 {
     /// <summary>
@@ -26,4 +28,10 @@ public EndpointDescriptionAttribute(string description)
 
     /// <inheritdoc />
     public string Description { get; }
+
+    /// <inheritdoc/>>
+    public override string ToString()
+    {
+        return $"Description: {Description ?? "(null)"}";
+    }
 }

src/Http/Http.Extensions/src/EndpointSummaryAttribute.cs

@@ -1,14 +1,17 @@
 // 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;
 using Microsoft.AspNetCore.Http.Metadata;
+using Microsoft.AspNetCore.Shared;
 
 namespace Microsoft.AspNetCore.Http;
 
 /// <summary>
 /// Specifies a summary in <see cref="Endpoint.Metadata"/>.
 /// </summary>
 [AttributeUsage(AttributeTargets.Method, Inherited = false, AllowMultiple = false)]
+[DebuggerDisplay("{ToString(),nq}")]
 public sealed class EndpointSummaryAttribute : Attribute, IEndpointSummaryMetadata
 {
     /// <summary>
@@ -22,4 +25,10 @@ public EndpointSummaryAttribute(string summary)
 
     /// <inheritdoc />
     public string Summary { get; }
+
+    /// <inheritdoc/>>
+    public override string ToString()
+    {
+        return DebuggerHelpers.GetDebugText(nameof(Summary), Summary);
+    }
 }

src/Http/Http.Extensions/src/Microsoft.AspNetCore.Http.Extensions.csproj

@@ -25,6 +25,7 @@
     <Compile Include="$(SharedSourceRoot)ValueStringBuilder\**\*.cs" LinkBase="Shared" />
     <Compile Include="$(SharedSourceRoot)Json\JsonSerializerExtensions.cs" LinkBase="Shared" />
     <Compile Include="$(SharedSourceRoot)RouteHandlers\ExecuteHandlerHelper.cs" LinkBase="Shared" />
+    <Compile Include="$(SharedSourceRoot)Debugger\DebuggerHelpers.cs" LinkBase="Shared" />
   </ItemGroup>
 
   <ItemGroup>

src/Http/Http.Extensions/src/PublicAPI.Unshipped.txt

@@ -1,4 +1,7 @@
 #nullable enable
+override Microsoft.AspNetCore.Http.EndpointDescriptionAttribute.ToString() -> string!
+override Microsoft.AspNetCore.Http.EndpointSummaryAttribute.ToString() -> string!
+override Microsoft.AspNetCore.Http.TagsAttribute.ToString() -> string!
 static Microsoft.AspNetCore.Http.HttpRequestJsonExtensions.ReadFromJsonAsync(this Microsoft.AspNetCore.Http.HttpRequest! request, System.Text.Json.Serialization.Metadata.JsonTypeInfo! jsonTypeInfo, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> System.Threading.Tasks.ValueTask<object?>
 static Microsoft.AspNetCore.Http.HttpResponseJsonExtensions.WriteAsJsonAsync(this Microsoft.AspNetCore.Http.HttpResponse! response, object? value, System.Text.Json.Serialization.Metadata.JsonTypeInfo! jsonTypeInfo, string? contentType = null, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> System.Threading.Tasks.Task!
 Microsoft.AspNetCore.Mvc.ProblemDetails.Extensions.set -> void (forwarded, contained in Microsoft.AspNetCore.Http.Abstractions)

src/Http/Http.Extensions/src/TagsAttribute.cs

@@ -1,7 +1,9 @@
 // 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;
 using Microsoft.AspNetCore.Http.Metadata;
+using Microsoft.AspNetCore.Shared;
 
 namespace Microsoft.AspNetCore.Http;
 
@@ -14,6 +16,7 @@ namespace Microsoft.AspNetCore.Http;
 /// and are typically used to group operations by tags in the UI.
 /// </remarks>
 [AttributeUsage(AttributeTargets.Method | AttributeTargets.Delegate | AttributeTargets.Class, Inherited = false, AllowMultiple = false)]
+[DebuggerDisplay("{ToString(),nq}")]
 public sealed class TagsAttribute : Attribute, ITagsMetadata
 {
     /// <summary>
@@ -29,4 +32,10 @@ public TagsAttribute(params string[] tags)
     /// Gets the collection of tags associated with the endpoint.
     /// </summary>
     public IReadOnlyList<string> Tags { get; }
+
+    /// <inheritdoc/>>
+    public override string ToString()
+    {
+        return DebuggerHelpers.GetDebugText(nameof(Tags), Tags);
+    }
 }

src/Http/Http.Extensions/test/MetadataTest.cs

@@ -0,0 +1,48 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Microsoft.AspNetCore.Http;
+
+namespace Microsoft.AspNetCore.Routing;
+
+public class MetadataTest
+{
+    [Fact]
+    public void EndpointDescriptionAttribute_ToString()
+    {
+        // Arrange
+        var metadata = new EndpointDescriptionAttribute("A description");
+
+        // Act
+        var value = metadata.ToString();
+
+        // Assert
+        Assert.Equal("Description: A description", value);
+    }
+
+    [Fact]
+    public void EndpointSummaryAttribute_ToString()
+    {
+        // Arrange
+        var metadata = new EndpointSummaryAttribute("A summary");
+
+        // Act
+        var value = metadata.ToString();
+
+        // Assert
+        Assert.Equal("Summary: A summary", value);
+    }
+
+    [Fact]
+    public void HostAttribute_ToString()
+    {
+        // Arrange
+        var metadata = new TagsAttribute("Tag1", "Tag2");
+
+        // Act
+        var value = metadata.ToString();
+
+        // Assert
+        Assert.Equal("Tags: Tag1,Tag2", value);
+    }
+}

src/Http/Routing/src/DataTokensMetadata.cs

@@ -1,9 +1,10 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-#nullable enable
-
+using System.Diagnostics;
+using System.Linq;
 using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Shared;
 
 namespace Microsoft.AspNetCore.Routing;
 
@@ -12,6 +13,7 @@ namespace Microsoft.AspNetCore.Routing;
 /// type provides data tokens value for <see cref="RouteData.DataTokens"/> associated
 /// with an endpoint.
 /// </summary>
+[DebuggerDisplay("{ToString(),nq}")]
 public sealed class DataTokensMetadata : IDataTokensMetadata
 {
     /// <summary>
@@ -27,4 +29,10 @@ public DataTokensMetadata(IReadOnlyDictionary<string, object?> dataTokens)
     /// Get the data tokens.
     /// </summary>
     public IReadOnlyDictionary<string, object?> DataTokens { get; }
+
+    /// <inheritdoc/>
+    public override string ToString()
+    {
+        return DebuggerHelpers.GetDebugText(nameof(DataTokens), DataTokens.Select(t => $"{t.Key}={t.Value ?? "(null)"}"));
+    }
 }

src/Http/Routing/src/EndpointNameMetadata.cs

@@ -1,7 +1,8 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Shared;
 
 namespace Microsoft.AspNetCore.Routing;
 
@@ -29,4 +30,10 @@ public EndpointNameMetadata(string endpointName)
     /// Gets the endpoint name.
     /// </summary>
     public string EndpointName { get; }
+
+    /// <inheritdoc/>
+    public override string ToString()
+    {
+        return DebuggerHelpers.GetDebugText(nameof(EndpointName), EndpointName);
+    }
 }

src/Http/Routing/src/ExcludeFromDescriptionAttribute.cs

@@ -1,16 +1,25 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// 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;
 using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Shared;
 
 namespace Microsoft.AspNetCore.Routing;
 
 /// <summary>
 /// Indicates that this <see cref="Endpoint"/> should not be included in the generated API metadata.
 /// </summary>
 [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method | AttributeTargets.Delegate, AllowMultiple = false, Inherited = true)]
+[DebuggerDisplay("{ToString(),nq}")]
 public sealed class ExcludeFromDescriptionAttribute : Attribute, IExcludeFromDescriptionMetadata
 {
     /// <inheritdoc />
     public bool ExcludeFromDescription => true;
+
+    /// <inheritdoc/>>
+    public override string ToString()
+    {
+        return DebuggerHelpers.GetDebugText(nameof(ExcludeFromDescription), ExcludeFromDescription);
+    }
 }

src/Http/Routing/src/HostAttribute.cs

@@ -3,13 +3,14 @@
 
 using System.Diagnostics;
 using System.Linq;
+using Microsoft.AspNetCore.Shared;
 
 namespace Microsoft.AspNetCore.Routing;
 
 /// <summary>
 /// Attribute for providing host metdata that is used during routing.
 /// </summary>
-[DebuggerDisplay("{DebuggerToString(),nq}")]
+[DebuggerDisplay("{ToString(),nq}")]
 [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = false, Inherited = false)]
 public sealed class HostAttribute : Attribute, IHostMetadata
 {
@@ -47,12 +48,13 @@ public HostAttribute(params string[] hosts)
     /// </summary>
     public IReadOnlyList<string> Hosts { get; }
 
-    private string DebuggerToString()
+    /// <inheritdoc/>
+    public override string ToString()
     {
         var hostsDisplay = (Hosts.Count == 0)
             ? "*:*"
             : string.Join(",", Hosts.Select(h => h.Contains(':') ? h : h + ":*"));
 
-        return $"Hosts: {hostsDisplay}";
+        return DebuggerHelpers.GetDebugText(nameof(Hosts), hostsDisplay);
     }
 }

src/Http/Routing/src/HttpMethodMetadata.cs

@@ -3,14 +3,15 @@
 
 using System.Diagnostics;
 using System.Linq;
+using Microsoft.AspNetCore.Shared;
 using static Microsoft.AspNetCore.Http.HttpMethods;
 
 namespace Microsoft.AspNetCore.Routing;
 
 /// <summary>
 /// Represents HTTP method metadata used during routing.
 /// </summary>
-[DebuggerDisplay("{DebuggerToString(),nq}")]
+[DebuggerDisplay("{ToString(),nq}")]
 public sealed class HttpMethodMetadata : IHttpMethodMetadata
 {
     /// <summary>
@@ -52,8 +53,9 @@ public HttpMethodMetadata(IEnumerable<string> httpMethods, bool acceptCorsPrefli
     /// </summary>
     public IReadOnlyList<string> HttpMethods { get; }
 
-    private string DebuggerToString()
+    /// <inheritdoc/>
+    public override string ToString()
     {
-        return $"HttpMethods: {string.Join(",", HttpMethods)} - Cors: {AcceptCorsPreflight}";
+        return DebuggerHelpers.GetDebugText(nameof(HttpMethods), HttpMethods, "Cors", AcceptCorsPreflight);
     }
 }

src/Http/Routing/src/Microsoft.AspNetCore.Routing.csproj

@@ -35,6 +35,7 @@
     <Compile Include="$(SharedSourceRoot)RouteValueDictionaryTrimmerWarning.cs" LinkBase="Shared" />
     <Compile Include="$(SharedSourceRoot)HttpRuleParser.cs" LinkBase="Shared" />
     <Compile Include="$(SharedSourceRoot)HttpParseResult.cs" LinkBase="Shared" />
+    <Compile Include="$(SharedSourceRoot)Debugger\DebuggerHelpers.cs" LinkBase="Shared" />
   </ItemGroup>
 
   <ItemGroup>

src/Http/Routing/src/PublicAPI.Unshipped.txt

@@ -1,5 +1,13 @@
 #nullable enable
 Microsoft.AspNetCore.Routing.RouteHandlerServices
+override Microsoft.AspNetCore.Routing.DataTokensMetadata.ToString() -> string!
+override Microsoft.AspNetCore.Routing.EndpointNameMetadata.ToString() -> string!
+override Microsoft.AspNetCore.Routing.ExcludeFromDescriptionAttribute.ToString() -> string!
+override Microsoft.AspNetCore.Routing.HostAttribute.ToString() -> string!
+override Microsoft.AspNetCore.Routing.HttpMethodMetadata.ToString() -> string!
+override Microsoft.AspNetCore.Routing.RouteNameMetadata.ToString() -> string!
+override Microsoft.AspNetCore.Routing.SuppressLinkGenerationMetadata.ToString() -> string!
+override Microsoft.AspNetCore.Routing.SuppressMatchingMetadata.ToString() -> string!
 Microsoft.AspNetCore.Builder.RouteShortCircuitEndpointConventionBuilderExtensions
 Microsoft.AspNetCore.Routing.RouteShortCircuitEndpointRouteBuilderExtensions
 static Microsoft.AspNetCore.Builder.RouteShortCircuitEndpointConventionBuilderExtensions.ShortCircuit(this Microsoft.AspNetCore.Builder.IEndpointConventionBuilder! builder, int? statusCode = null) -> Microsoft.AspNetCore.Builder.IEndpointConventionBuilder!