From 9b7c0dd089784af1dd6c3f5104e5d208be15c72c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Javier=20Garc=C3=ADa=20de=20la=20Noceda=20Arg=C3=BCelles?=
 <j.garciadelanoceda@gmail.com>
Date: Sun, 23 Jun 2024 14:00:23 +0200
Subject: [PATCH] Fix parameter filter for Minimal APIs (#2962)

Fix `InvalidCastException` for Minimal APIs when retrieving `[SwaggerParameter]`.
---
 .../AnnotationsParameterFilter.cs                 |  5 ++---
 test/WebSites/WebApi/Program.cs                   | 15 ++++++++++++++-
 test/WebSites/WebApi/WebApi.csproj                |  1 +
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/Swashbuckle.AspNetCore.Annotations/AnnotationsParameterFilter.cs b/src/Swashbuckle.AspNetCore.Annotations/AnnotationsParameterFilter.cs
index 1c0304042a..2990329382 100644
--- a/src/Swashbuckle.AspNetCore.Annotations/AnnotationsParameterFilter.cs
+++ b/src/Swashbuckle.AspNetCore.Annotations/AnnotationsParameterFilter.cs
@@ -31,8 +31,7 @@ private void ApplyPropertyAnnotations(OpenApiParameter parameter, PropertyInfo p
         private void ApplyParamAnnotations(OpenApiParameter parameter, ParameterInfo parameterInfo)
         {
 
-            var swaggerParameterAttribute = parameterInfo.GetCustomAttributes<SwaggerParameterAttribute>()
-                .FirstOrDefault();
+            var swaggerParameterAttribute = parameterInfo.GetCustomAttribute<SwaggerParameterAttribute>();
 
             if (swaggerParameterAttribute != null)
                 ApplySwaggerParameterAttribute(parameter, swaggerParameterAttribute);
@@ -47,4 +46,4 @@ private void ApplySwaggerParameterAttribute(OpenApiParameter parameter, SwaggerP
                 parameter.Required = swaggerParameterAttribute.RequiredFlag.Value;
         }
     }
-}
\ No newline at end of file
+}
diff --git a/test/WebSites/WebApi/Program.cs b/test/WebSites/WebApi/Program.cs
index dc5b28abe7..834c8a8c49 100644
--- a/test/WebSites/WebApi/Program.cs
+++ b/test/WebSites/WebApi/Program.cs
@@ -1,8 +1,12 @@
+using Microsoft.AspNetCore.Mvc;
+using Swashbuckle.AspNetCore.Annotations;
+
 var builder = WebApplication.CreateBuilder(args);
 
 builder.Services.AddEndpointsApiExplorer();
 builder.Services.AddSwaggerGen(c =>
 {
+    c.EnableAnnotations();
     c.SwaggerDoc("v1", new() { Title = "WebApi", Version = "v1" });
 });
 
@@ -20,7 +24,7 @@
 
 app.MapGet("/weatherforecast", () =>
 {
-    var forecast =  Enumerable.Range(1, 5).Select(index =>
+    var forecast = Enumerable.Range(1, 5).Select(index =>
         new WeatherForecast
         (
             DateOnly.FromDateTime(DateTime.Now.AddDays(index)),
@@ -33,12 +37,21 @@
 .WithName("GetWeatherForecast")
 .WithOpenApi();
 
+app.MapPost("/fruit/{id}", ([AsParameters] CreateFruitModel model) =>
+{
+    return model.Fruit;
+}).WithName("CreateFruit");
+
 app.Run();
 
+record struct CreateFruitModel
+    ([FromRoute, SwaggerParameter(Description = "The id of the fruit that will be created", Required = true)] string Id,
+    [FromBody] Fruit Fruit);
 record WeatherForecast(DateOnly Date, int TemperatureC, string? Summary)
 {
     public int TemperatureF => 32 + (int)(TemperatureC / 0.5556);
 }
+record Fruit(string Name);
 
 namespace WebApi
 {
diff --git a/test/WebSites/WebApi/WebApi.csproj b/test/WebSites/WebApi/WebApi.csproj
index 727da5ac8b..5f0339397b 100644
--- a/test/WebSites/WebApi/WebApi.csproj
+++ b/test/WebSites/WebApi/WebApi.csproj
@@ -8,6 +8,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <ProjectReference Include="..\..\..\src\Swashbuckle.AspNetCore.Annotations\Swashbuckle.AspNetCore.Annotations.csproj" />
     <ProjectReference Include="..\..\..\src\Swashbuckle.AspNetCore.SwaggerGen\Swashbuckle.AspNetCore.SwaggerGen.csproj" />
     <ProjectReference Include="..\..\..\src\Swashbuckle.AspNetCore.SwaggerUI\Swashbuckle.AspNetCore.SwaggerUI.csproj" />
   </ItemGroup>