Add applying annotations with [Description] attributes for types

Author: desjoerd

src/OpenApi/src/Services/Schemas/OpenApiSchemaService.cs

@@ -101,6 +101,10 @@ internal sealed class OpenApiSchemaService(
             {
                 schema.ApplyNullabilityContextInfo(jsonPropertyInfo);
             }
+            if (context.TypeInfo.Type.GetCustomAttributes(inherit: false).OfType<DescriptionAttribute>().LastOrDefault() is DescriptionAttribute typeDescriptionAttribute)
+            {
+                schema[OpenApiSchemaKeywords.DescriptionKeyword] = typeDescriptionAttribute.Description;
+            }
             if (context.PropertyInfo is { AttributeProvider: { } attributeProvider })
             {
                 var isInlinedSchema = schema["x-schema-id"] is null;
@@ -128,7 +132,7 @@ internal sealed class OpenApiSchemaService(
                 }
             }
 
-                return schema;
+            return schema;
         }
     };
 

src/OpenApi/test/Microsoft.AspNetCore.OpenApi.Tests/Services/OpenApiSchemaService/OpenApiSchemaService.Annotations.cs

@@ -50,9 +50,8 @@ await VerifyOpenApiDocument(builder, document =>
                     Assert.Null(reference.Reference.Description);
                 });
 
-            var childSchema = document.Components.Schemas["DescribedChildDto"];
-            // TODO: Handle descriptions on classes
-            // Assert.Equal("Class: DescribedChildDto", "DescribedChildDto");
+            var referencedSchema = document.Components.Schemas["DescribedChildDto"];
+            Assert.Equal("Class: DescribedChildDto", referencedSchema.Description);
         });
 
     }
@@ -118,8 +117,7 @@ await VerifyOpenApiDocument(builder, options, document =>
                 {
                     Assert.Equal("inlinedNoDescription", property.Key);
                     var inlinedSchema = Assert.IsType<OpenApiSchema>(property.Value);
-                    // TODO: Handle descriptions on classes
-                    // Assert.Equal("Class: DescribedInlinedDto", inlinedSchema.Description);
+                    Assert.Equal("Class: DescribedInlinedDto", inlinedSchema.Description);
                 });
         });
     }