Fix issue #2057 related to readonly properties set via constructor

src/Directory.Build.props

@@ -6,7 +6,7 @@
     <PublishRepositoryUrl>true</PublishRepositoryUrl>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
     <LicenseUrl>https://licenses.nuget.org/MIT</LicenseUrl>
-    <VersionPrefix>6.1.0</VersionPrefix>
+    <VersionPrefix>6.1.1</VersionPrefix>
   </PropertyGroup>
 
   <ItemGroup>

src/Swashbuckle.AspNetCore.Newtonsoft/SchemaGenerator/NewtonsoftDataContractResolver.cs

@@ -146,7 +146,13 @@ private IEnumerable<DataProperty> GetDataPropertiesFor(JsonObjectContract jsonOb
 
                 var isSetViaConstructor = jsonProperty.DeclaringType != null && jsonProperty.DeclaringType.GetConstructors()
                     .SelectMany(c => c.GetParameters())
-                    .Any(p => string.Equals(p.Name, jsonProperty.PropertyName, StringComparison.OrdinalIgnoreCase));
+                    .Any(p =>
+                    {
+                        // Newtonsoft supports setting via constructor if either underlying OR JSON names match
+                        return
+                            string.Equals(p.Name, jsonProperty.UnderlyingName, StringComparison.OrdinalIgnoreCase) ||
+                            string.Equals(p.Name, jsonProperty.PropertyName, StringComparison.OrdinalIgnoreCase);
+                    });
 
                 jsonProperty.TryGetMemberInfo(out MemberInfo memberInfo);
 

test/Swashbuckle.AspNetCore.Newtonsoft.Test/Fixtures/TypeWithPropertiesSetViaConstructor.cs

@@ -0,0 +1,18 @@
+using Newtonsoft.Json;
+
+namespace Swashbuckle.AspNetCore.Newtonsoft.Test
+{
+    public class TypeWithPropertiesSetViaConstructor
+    {
+        public TypeWithPropertiesSetViaConstructor(int id, string description)
+        {
+            Id = id;
+            Description = description;
+        }
+
+        public int Id { get; }
+
+        [JsonProperty("Desc")]
+        public string Description { get; }
+    }
+}

test/Swashbuckle.AspNetCore.Newtonsoft.Test/SchemaGenerator/NewtonsoftSchemaGeneratorTests.cs

@@ -327,14 +327,15 @@ public void GenerateSchema_SetsReadOnlyAndWriteOnlyFlags_IfPropertyIsRestricted(
         }
 
         [Fact]
-        public void GenerateSchema_DoesNotSetReadOnlyFlag_IfPropertyIsReadOnlyButSetViaConstructor()
+        public void GenerateSchema_DoesNotSetReadOnlyFlag_IfPropertyIsReadOnlyButCanBeSetViaConstructor()
         {
             var schemaRepository = new SchemaRepository();
 
-            var referenceSchema = Subject().GenerateSchema(typeof(TypeWithPropertySetViaConstructor), schemaRepository);
+            var referenceSchema = Subject().GenerateSchema(typeof(TypeWithPropertiesSetViaConstructor), schemaRepository);
 
             var schema = schemaRepository.Schemas[referenceSchema.Reference.Id];
-            Assert.False(schema.Properties["ReadOnlyProperty"].ReadOnly);
+            Assert.False(schema.Properties["Id"].ReadOnly);
+            Assert.False(schema.Properties["Desc"].ReadOnly);
         }
 
         [Theory]