Adding support for QueryResult in Swagger

Source/DotNET/Applications/Queries/QueryMethodExtensions.cs

@@ -0,0 +1,27 @@
+// Copyright (c) Cratis. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.Reflection;
+using Cratis.Reflection;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Cratis.Applications.Queries;
+
+/// <summary>
+/// Extension methods for methods representing commands.
+/// </summary>
+public static class QueryMethodExtensions
+{
+    /// <summary>
+    /// Check if a method is a command.
+    /// </summary>
+    /// <param name="methodInfo">The <see cref="MethodInfo"/> to check.</param>
+    /// <returns>True if it is a command, false if not.</returns>
+    public static bool IsQuery(this MethodInfo methodInfo) =>
+        methodInfo.HasAttribute<HttpGetAttribute>() &&
+        methodInfo.ReturnType != typeof(void) &&
+        methodInfo.ReturnType != typeof(Task) &&
+        methodInfo.ReturnType != typeof(ValueTask) &&
+        !methodInfo.HasAttribute<AspNetResultAttribute>() &&
+        (!methodInfo.DeclaringType?.HasAttribute<AspNetResultAttribute>() ?? false);
+}

Source/DotNET/Swagger/Extensions.cs

@@ -19,5 +19,6 @@ public static void AddConcepts(this SwaggerGenOptions options)
     {
         options.SchemaFilter<ConceptSchemaFilter>();
         options.OperationFilter<CommandResultOperationFilter>();
+        options.OperationFilter<QueryResultOperationFilter>();
     }
 }

Source/DotNET/Swagger/QueryResultOperationFilter.cs

@@ -0,0 +1,43 @@
+// Copyright (c) Cratis. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using Cratis.Applications.Queries;
+using Cratis.Concepts;
+using Cratis.Reflection;
+using Microsoft.OpenApi.Models;
+using Swashbuckle.AspNetCore.SwaggerGen;
+
+namespace Cratis.Applications.Swagger;
+
+/// <summary>
+/// Represents an implementation of <see cref="IOperationFilter"/> that adds the command result to the operation for command methods.
+/// </summary>
+/// <param name="schemaGenerator">The <see cref="ISchemaGenerator"/> to use.</param>
+public class QueryResultOperationFilter(ISchemaGenerator schemaGenerator) : IOperationFilter
+{
+    /// <inheritdoc/>
+    public void Apply(OpenApiOperation operation, OperationFilterContext context)
+    {
+        if (!context.MethodInfo.IsQuery()) return;
+
+        var returnType = context.MethodInfo.GetActualReturnType();
+
+        if (returnType.IsConcept())
+        {
+            returnType = returnType.GetConceptValueType();
+        }
+
+        var queryResultType = typeof(QueryResult<>).MakeGenericType(returnType);
+
+        var schema = schemaGenerator.GenerateSchema(queryResultType, context.SchemaRepository);
+        var response = operation.Responses.First().Value;
+        if (response.Content.ContainsKey("application/json"))
+        {
+            operation.Responses.First().Value.Content["application/json"].Schema = schema;
+        }
+        else
+        {
+            response.Content.Add(new("application/json", new() { Schema = schema }));
+        }
+    }
+}