Add option to explicitly exclude types from schema (#1670)

Co-authored-by: Rico Suter <mail@rsuter.com>

Author: Havret

src/NJsonSchema.Tests/Generation/SystemTextJson/SystemTextJsonTests.cs

@@ -1,5 +1,7 @@
 using System.ComponentModel.DataAnnotations;
 using System.Threading.Tasks;
+using NJsonSchema.Annotations;
+using NJsonSchema.Generation;
 using Xunit;
 
 namespace NJsonSchema.Tests.Generation.SystemTextJson
@@ -34,6 +36,59 @@ public async Task When_property_is_readonly_then_its_in_the_schema()
             Assert.Contains(@"Name", data);
             Assert.Contains(@"Description", data);
         }
+        
+        public class ContainerType1
+        {
+            public int Property { get; set; }
+            public NestedType1 NestedType { get; set; }
+        }
+        
+        public class NestedType1
+        {
+            public int NestedProperty { get; set; }
+        }
+
+        [Fact]
+        public async Task When_type_is_excluded_then_it_should_not_be_in_the_schema()
+        {
+            //// Act
+            var schema = JsonSchema.FromType<ContainerType1>(new SystemTextJsonSchemaGeneratorSettings
+            {
+                ExcludedTypeNames = [typeof(NestedType1).FullName]
+            });
+            var data = schema.ToJson();
+            
+            //// Assert
+            Assert.NotNull(data);
+            Assert.DoesNotContain(@"NestedType1", data);
+            Assert.Contains(@"Property", data);
+        }
+        
+        public class ContainerType2
+        {
+            public int Property { get; set; }
+            
+            [JsonSchemaIgnore]
+            public NestedType2 NestedType { get; set; }
+        }
+        
+        public class NestedType2
+        {
+            public int NestedProperty { get; set; }
+        }
+        
+        [Fact]
+        public async Task When_type_is_excluded_with_json_schema_ignore_attribute_then_it_should_not_be_in_the_schema()
+        {
+            //// Act
+            var schema = JsonSchema.FromType<ContainerType2>();
+            var data = schema.ToJson();
+            
+            //// Assert
+            Assert.NotNull(data);
+            Assert.DoesNotContain(@"NestedType2", data);
+            Assert.Contains(@"Property", data);
+        }
 
         [Fact]
         public async Task When_property_is_private_and_readonly_then_its_not_in_the_schema()

src/NJsonSchema/Generation/SystemTextJsonReflectionService.cs

@@ -68,7 +68,8 @@ public override void GenerateProperties(JsonSchema schema, ContextualType contex
                 var ignored = propertyIgnored
                     || schemaGenerator.IsPropertyIgnoredBySettings(accessorInfo)
                     || accessorInfo.GetAttributes(true)
-                        .FirstAssignableToTypeNameOrDefault("System.Text.Json.Serialization.JsonExtensionDataAttribute", TypeNameStyle.FullName) != null;
+                        .FirstAssignableToTypeNameOrDefault("System.Text.Json.Serialization.JsonExtensionDataAttribute", TypeNameStyle.FullName) != null
+                    || settings.ExcludedTypeNames.Contains(accessorInfo.AccessorType.Type.FullName);
 
                 if (!ignored)
                 {