Fix Minimal API endpoints not being part of OpenAPI document in ASP.Versioning v10 preview

src/AspNetCore/WebApi/src/Asp.Versioning.Mvc.ApiExplorer/DependencyInjection/IApiVersioningBuilderExtensions.cs

@@ -58,7 +58,12 @@ private static void AddApiExplorerServices( IApiVersioningBuilder builder )
 
         var services = builder.Services;
 
+        // registers DefaultApiDescriptionProvider, which discovers controller-based endpoints
         services.AddMvcCore().AddApiExplorer();
+
+        // registers EndpointMetadataApiDescriptionProvider, which discovers minimal API endpoints.
+        // both providers are required so that OpenApiDocumentService sees all endpoints.
+        services.AddEndpointsApiExplorer();
         services.TryAddSingleton<IOptionsFactory<ApiExplorerOptions>, ApiExplorerOptionsFactory<ApiExplorerOptions>>();
         services.TryAddTransient<IApiVersionDescriptionProviderFactory, ApiVersionDescriptionProviderFactory>();
         services.TryAddSingleton( static sp => sp.GetRequiredService<IApiVersionDescriptionProviderFactory>().Create() );

src/AspNetCore/WebApi/test/Asp.Versioning.OpenApi.Tests/AssumeCultureAttribute.cs

@@ -0,0 +1,39 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+
+namespace Asp.Versioning;
+
+using System.Globalization;
+using System.Reflection;
+using static System.AttributeTargets;
+using static System.Threading.Thread;
+
+/// <summary>
+/// Allows a test method to assume that it is running in a specific locale.
+/// </summary>
+[AttributeUsage( Class | Method, AllowMultiple = false, Inherited = true )]
+internal sealed class AssumeCultureAttribute : BeforeAfterTestAttribute
+{
+    private CultureInfo originalCulture;
+    private CultureInfo originalUICulture;
+
+    public AssumeCultureAttribute( string name ) => Name = name;
+
+    public string Name { get; }
+
+    public override void Before( MethodInfo methodUnderTest, IXunitTest test )
+    {
+        originalCulture = CurrentThread.CurrentCulture;
+        originalUICulture = CurrentThread.CurrentUICulture;
+
+        var culture = CultureInfo.CreateSpecificCulture( Name );
+
+        CurrentThread.CurrentCulture = culture;
+        CurrentThread.CurrentUICulture = culture;
+    }
+
+    public override void After( MethodInfo methodUnderTest, IXunitTest test )
+    {
+        CurrentThread.CurrentCulture = originalCulture;
+        CurrentThread.CurrentUICulture = originalUICulture;
+    }
+}

src/AspNetCore/WebApi/test/Asp.Versioning.OpenApi.Tests/Content/v1-minimal.json

@@ -0,0 +1,86 @@
+{
+  "openapi": "3.1.1",
+  "info": {
+    "title": "Test API | v1",
+    "description": "The API was deprecated on 1/1/2026. The API was sunset on 2/10/2026.\r\n\r\n### Links\r\n\r\n- [Version Deprecation Policy](http://my.api.com/policies/versions/deprecated.html)\r\n- [Version Sunset Policy](http://my.api.com/policies/versions/sunset.html)",
+    "version": "1.0"
+  },
+  "servers": [
+    {
+      "url": "http://localhost/"
+    }
+  ],
+  "paths": {
+    "/test/{id}": {
+      "get": {
+        "tags": [
+          "Test"
+        ],
+        "summary": "",
+        "description": "",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "description": "",
+            "required": true,
+            "schema": {
+              "pattern": "^-?(?:0|[1-9]\\d*)$",
+              "type": "integer",
+              "format": "int32"
+            }
+          },
+          {
+            "name": "api-version",
+            "in": "query",
+            "description": "The requested API version",
+            "required": true,
+            "schema": {
+              "type": "string",
+              "default": "1.0"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "pattern": "^-?(?:0|[1-9]\\d*)$",
+                  "type": [
+                    "integer",
+                    "string"
+                  ],
+                  "format": "int32"
+                }
+              }
+            }
+          },
+          "400": {
+            "description": "Bad Request"
+          }
+        }
+      }
+    }
+  },
+  "tags": [
+    {
+      "name": "Test"
+    }
+  ],
+  "x-api-versioning": [
+    {
+      "title": "Version Deprecation Policy",
+      "type": "text/html",
+      "rel": "deprecation",
+      "url": "http://my.api.com/policies/versions/deprecated.html"
+    },
+    {
+      "title": "Version Sunset Policy",
+      "type": "text/html",
+      "rel": "sunset",
+      "url": "http://my.api.com/policies/versions/sunset.html"
+    }
+  ]
+}

src/AspNetCore/WebApi/test/Asp.Versioning.OpenApi.Tests/Content/v1-mixed.json

@@ -0,0 +1,157 @@
+{
+  "openapi": "3.1.1",
+  "info": {
+    "title": "Test API | v1",
+    "description": "The API was deprecated on 1/1/2026. The API was sunset on 2/10/2026.\r\n\r\n### Links\r\n\r\n- [Version Deprecation Policy](http://my.api.com/policies/versions/deprecated.html)\r\n- [Version Sunset Policy](http://my.api.com/policies/versions/sunset.html)",
+    "version": "1.0"
+  },
+  "servers": [
+    {
+      "url": "http://localhost/"
+    }
+  ],
+  "paths": {
+    "/minimal/{id}": {
+      "get": {
+        "tags": [
+          "Test"
+        ],
+        "summary": "",
+        "description": "",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "description": "",
+            "required": true,
+            "schema": {
+              "pattern": "^-?(?:0|[1-9]\\d*)$",
+              "type": "integer",
+              "format": "int32"
+            }
+          },
+          {
+            "name": "api-version",
+            "in": "query",
+            "description": "The requested API version",
+            "required": true,
+            "schema": {
+              "type": "string",
+              "default": "1.0"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "pattern": "^-?(?:0|[1-9]\\d*)$",
+                  "type": [
+                    "integer",
+                    "string"
+                  ],
+                  "format": "int32"
+                }
+              }
+            }
+          },
+          "400": {
+            "description": "Bad Request"
+          }
+        }
+      }
+    },
+    "/Test": {
+      "get": {
+        "tags": [
+          "Test"
+        ],
+        "summary": "",
+        "description": "",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "query",
+            "description": "",
+            "schema": {
+              "pattern": "^-?(?:0|[1-9]\\d*)$",
+              "type": [
+                "integer",
+                "string"
+              ],
+              "format": "int32"
+            }
+          },
+          {
+            "name": "api-version",
+            "in": "query",
+            "description": "The requested API version",
+            "required": true,
+            "schema": {
+              "type": "string",
+              "default": "1.0"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "text/plain": {
+                "schema": {
+                  "pattern": "^-?(?:0|[1-9]\\d*)$",
+                  "type": [
+                    "integer",
+                    "string"
+                  ],
+                  "format": "int32"
+                }
+              },
+              "application/json": {
+                "schema": {
+                  "pattern": "^-?(?:0|[1-9]\\d*)$",
+                  "type": [
+                    "integer",
+                    "string"
+                  ],
+                  "format": "int32"
+                }
+              },
+              "text/json": {
+                "schema": {
+                  "pattern": "^-?(?:0|[1-9]\\d*)$",
+                  "type": [
+                    "integer",
+                    "string"
+                  ],
+                  "format": "int32"
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  },
+  "tags": [
+    {
+      "name": "Test"
+    }
+  ],
+  "x-api-versioning": [
+    {
+      "title": "Version Deprecation Policy",
+      "type": "text/html",
+      "rel": "deprecation",
+      "url": "http://my.api.com/policies/versions/deprecated.html"
+    },
+    {
+      "title": "Version Sunset Policy",
+      "type": "text/html",
+      "rel": "sunset",
+      "url": "http://my.api.com/policies/versions/sunset.html"
+    }
+  ]
+}