Respect IModelNameProvider when matching OpenAPI parameters

src/OpenApi/gen/XmlCommentGenerator.Emitter.cs

@@ -57,6 +57,7 @@ namespace Microsoft.AspNetCore.OpenApi.Generated
     using System.Threading.Tasks;
     using Microsoft.AspNetCore.OpenApi;
     using Microsoft.AspNetCore.Mvc.Controllers;
+    using Microsoft.AspNetCore.Mvc.ModelBinding;
     using Microsoft.AspNetCore.Mvc.ModelBinding.Metadata;
     using Microsoft.Extensions.DependencyInjection;
     using Microsoft.OpenApi;
@@ -153,30 +154,6 @@ public static string CreateDocumentationId(this PropertyInfo property)
             return sb.ToString();
         }
 
-        /// <summary>
-        /// Generates a documentation comment ID for a property given its container type and property name.
-        /// Example: P:Namespace.ContainingType.PropertyName
-        /// </summary>
-        public static string CreateDocumentationId(Type containerType, string propertyName)
-        {
-            if (containerType == null)
-            {
-                throw new ArgumentNullException(nameof(containerType));
-            }
-            if (string.IsNullOrEmpty(propertyName))
-            {
-                throw new ArgumentException("Property name cannot be null or empty.", nameof(propertyName));
-            }
-
-            var sb = new StringBuilder();
-            sb.Append("P:");
-            sb.Append(GetTypeDocId(containerType, includeGenericArguments: false, omitGenericArity: false));
-            sb.Append('.');
-            sb.Append(propertyName);
-
-            return sb.ToString();
-        }
-
         /// <summary>
         /// Generates a documentation comment ID for a method (or constructor).
         /// For example:
@@ -389,7 +366,11 @@ public Task TransformAsync(OpenApiOperation operation, OpenApiOperationTransform
                     foreach (var parameterComment in methodComment.Parameters)
                     {
                         var parameterInfo = methodInfo.GetParameters().SingleOrDefault(info => info.Name == parameterComment.Name);
-                        var operationParameter = operation.Parameters?.SingleOrDefault(parameter => parameter.Name == parameterComment.Name);
+                        if (parameterInfo is null || parameterInfo.ParameterType == typeof(CancellationToken))
+                        {
+                            continue;
+                        }
+                        var operationParameter = GetOperationParameter(operation, parameterInfo);
                         if (operationParameter is not null)
                         {
                             var targetOperationParameter = UnwrapOpenApiParameter(operationParameter);
@@ -449,10 +430,14 @@ public Task TransformAsync(OpenApiOperation operation, OpenApiOperationTransform
                     && metadata.ContainerType is { } containerType
                     && metadata.PropertyName is { } propertyName)
                 {
-                    var propertyDocId = DocumentationCommentIdHelper.CreateDocumentationId(containerType, propertyName);
-                    if (XmlCommentCache.Cache.TryGetValue(DocumentationCommentIdHelper.NormalizeDocId(propertyDocId), out var propertyComment))
+                    var propertyInfo = containerType.GetProperty(propertyName);
+                    if (propertyInfo is null)
+                    {
+                        continue;
+                    }
+                    if (XmlCommentCache.Cache.TryGetValue(DocumentationCommentIdHelper.NormalizeDocId(propertyInfo.CreateDocumentationId()), out var propertyComment))
                     {
-                        var parameter = operation.Parameters?.SingleOrDefault(p => p.Name == metadata.Name);
+                        var parameter = GetOperationParameter(operation, propertyInfo);
                         var description = propertyComment.Summary;
                         if (!string.IsNullOrEmpty(description) && !string.IsNullOrEmpty(propertyComment.Value))
                         {
@@ -499,6 +484,61 @@ public Task TransformAsync(OpenApiOperation operation, OpenApiOperationTransform
             return Task.CompletedTask;
         }
 
+        private static IOpenApiParameter? GetOperationParameter(OpenApiOperation operation, PropertyInfo propertyInfo)
+        {
+            return GetOperationParameter(operation, propertyInfo, propertyInfo.Name);
+        }
+
+        private static IOpenApiParameter? GetOperationParameter(OpenApiOperation operation, ParameterInfo parameterInfo)
+        {
+            return GetOperationParameter(operation, parameterInfo, parameterInfo.Name);
+        }
+
+        private static IOpenApiParameter? GetOperationParameter(OpenApiOperation operation, ICustomAttributeProvider attributeProvider, string? name)
+        {
+            var parameters = operation.Parameters;
+            if (parameters is null)
+            {
+                return null;
+            }
+
+            var modelNames = GetModelNames(attributeProvider, name);
+
+            foreach (var parameter in parameters)
+            {
+                var parameterName = parameter.Name;
+
+                if (string.IsNullOrEmpty(parameterName))
+                {
+                    continue;
+                }
+
+                if (modelNames.Contains(parameterName))
+                {
+                    return parameter;
+                }
+            }
+
+            return null;
+        }
+
+        private static IReadOnlySet<string> GetModelNames(ICustomAttributeProvider attributeProvider, string? name)
+        {
+            var modelNames = attributeProvider
+                .GetCustomAttributes(inherit: false)
+                .OfType<IModelNameProvider>()
+                .Where(p => !string.IsNullOrEmpty(p.Name))
+                .Select(p => p.Name!)
+                .ToHashSet();
+
+            if (!string.IsNullOrEmpty(name))
+            {
+                modelNames.Add(name);
+            }
+
+            return modelNames;
+        }
+
         private static OpenApiParameter UnwrapOpenApiParameter(IOpenApiParameter sourceParameter)
         {
             if (sourceParameter is OpenApiParameterReference parameterReference)

src/OpenApi/test/Microsoft.AspNetCore.OpenApi.SourceGenerators.Tests/OperationTests.Controllers.cs

@@ -124,7 +124,7 @@ public class TestController : ControllerBase
 {
     /// <param name="userId">The id of the user.</param>
     [HttpGet("{userId}")]
-    public string Get()
+    public string Get(int userId)
     {
         return "Hello, World!";
     }
@@ -141,4 +141,121 @@ await SnapshotTestHelper.VerifyOpenApi(compilation, document =>
             Assert.Equal("The id of the user.", path.Parameters[0].Description);
         });
     }
+
+    [Fact]
+    public async Task SupportsParametersWithCustomNamesFromControllers()
+    {
+        var source =
+"""
+using System.Collections.Generic;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.DependencyInjection;
+
+var builder = WebApplication.CreateBuilder();
+
+builder.Services
+    .AddControllers()
+    .AddApplicationPart(typeof(TestController).Assembly);
+builder.Services.AddOpenApi();
+
+var app = builder.Build();
+
+app.MapControllers();
+
+app.Run();
+
+[ApiController]
+[Route("[controller]")]
+public class TestController : ControllerBase
+{
+    /// <param name="userId">The id of the user.</param>
+    [HttpGet("{user_id}")]
+    public string Get([FromRoute(Name = "user_id")] int userId)
+    {
+        return "Hello, World!";
+    }
+
+    [HttpGet]
+    public IEnumerable<Person> Search(Query query)
+    {
+        return [];
+    }
+}
+
+public partial class Program {}
+
+public record Person(int Id, string Name);
+
+public class Query
+{
+    /// <summary>
+    /// The full name of the person.
+    /// </summary>
+    [FromQuery(Name = "full_name")]
+    public string? Name { get; init; }
+}
+""";
+        var generator = new XmlCommentGenerator();
+        await SnapshotTestHelper.Verify(source, generator, out var compilation);
+        await SnapshotTestHelper.VerifyOpenApi(compilation, document =>
+        {
+            var getOperation = document.Paths["/Test/{user_id}"].Operations[HttpMethod.Get];
+            Assert.Equal("user_id", getOperation.Parameters[0].Name);
+            Assert.Equal("The id of the user.", getOperation.Parameters[0].Description);
+
+            var searchOperation = document.Paths["/Test"].Operations[HttpMethod.Get];
+            Assert.Equal("full_name", searchOperation.Parameters[0].Name);
+            Assert.Equal("The full name of the person.", searchOperation.Parameters[0].Description);
+        });
+    }
+
+    [Fact]
+    public async Task ShouldNotApplyCancellationTokenDocumentationToRequestBody()
+    {
+        var source =
+"""
+using System.Collections.Generic;
+using System.Threading;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.DependencyInjection;
+
+var builder = WebApplication.CreateBuilder();
+
+builder.Services
+    .AddControllers()
+    .AddApplicationPart(typeof(TestController).Assembly);
+builder.Services.AddOpenApi();
+
+var app = builder.Build();
+
+app.MapControllers();
+
+app.Run();
+
+[ApiController]
+[Route("[controller]")]
+public class TestController : ControllerBase
+{
+    /// <param name="cancellationToken">The cancellation token.</param>
+    [HttpGet]
+    public ActionResult Create(Person person, CancellationToken cancellationToken)
+    {
+        return Created();
+    }
+}
+
+public partial class Program {}
+
+public record Person(int Id, string Name);
+""";
+        var generator = new XmlCommentGenerator();
+        await SnapshotTestHelper.Verify(source, generator, out var compilation);
+        await SnapshotTestHelper.VerifyOpenApi(compilation, document =>
+        {
+            var getOperation = document.Paths["/Test"].Operations[HttpMethod.Get];
+            Assert.Null(getOperation.RequestBody.Description);
+        });
+    }
 }