Merge branch 'type-serialization'

README.md

@@ -45,6 +45,10 @@ Please read [CONTRIBUTING.md](CONTRIBUTING.md) for guidelines.
 
 # Changelog
 
+## Version 4.3.0
+
+* Add support for (de)serialization of System.Type
+
 ## Version 4.2.4
 
 * Refactored the project and solution so that they load and build cleanly in VS2017.

YamlDotNet.Test/Serialization/SerializationTests.cs

@@ -1488,21 +1488,21 @@ static Exception GetExceptionWithStackTrace()
         public void RegisteringATypeConverterPreventsTheTypeFromBeingVisited()
         {
             var serializer = new SerializerBuilder()
-                .WithTypeConverter(new SystemTypeTypeConverter())
+                .WithTypeConverter(new NonSerializableTypeConverter())
                 .Build();
 
-            var yaml = serializer.Serialize(new TypeContainer
+            var yaml = serializer.Serialize(new NonSerializableContainer
             {
-                Type = typeof(string),
+                Value = new NonSerializable { Text = "hello" },
             });
 
             var deserializer = new DeserializerBuilder()
-                .WithTypeConverter(new SystemTypeTypeConverter())
+                .WithTypeConverter(new NonSerializableTypeConverter())
                 .Build();
 
-            var result = deserializer.Deserialize<TypeContainer>(yaml);
+            var result = deserializer.Deserialize<NonSerializableContainer>(yaml);
 
-            Assert.Equal(typeof(string), result.Type);
+            Assert.Equal("hello", result.Value.Text);
         }
 
         [Fact]
@@ -1531,34 +1531,62 @@ public void NamingConventionIsNotAppliedByDeserializerWhenApplyNamingConventions
             Assert.Equal("value", parsed.NoConvention);
         }
 
+        [Fact]
+        public void TypesAreSerializable()
+        {
+            var sut = new SerializerBuilder()
+                .Build();
+
+            var yaml = sut.Serialize(typeof(string));
+
+            Assert.Contains(typeof(string).AssemblyQualifiedName, yaml);
+        }
+
+        [Fact]
+        public void TypesAreDeserializable()
+        {
+            var sut = new DeserializerBuilder()
+                .Build();
+
+            var type = sut.Deserialize<Type>(typeof(string).AssemblyQualifiedName);
+
+            Assert.Equal(typeof(string), type);
+        }
+
         public class NamingConventionDisabled
         {
             [YamlMember(ApplyNamingConventions = false)]
             public string NoConvention { get; set; }
         }
 
-        public class TypeContainer
+        public class NonSerializableContainer
         {
-            public Type Type { get; set; }
+            public NonSerializable Value { get; set; }
+        }
+
+        public class NonSerializable
+        {
+            public string WillThrow { get { throw new Exception(); } }
+
+            public string Text { get; set; }
         }
 
-        public class SystemTypeTypeConverter : IYamlTypeConverter
+        public class NonSerializableTypeConverter : IYamlTypeConverter
         {
             public bool Accepts(Type type)
             {
-                return typeof(Type).IsAssignableFrom(type);
+                return typeof(NonSerializable).IsAssignableFrom(type);
             }
 
             public object ReadYaml(IParser parser, Type type)
             {
                 var scalar = parser.Expect<Scalar>();
-                return Type.GetType(scalar.Value);
+                return new NonSerializable { Text = scalar.Value };
             }
 
             public void WriteYaml(IEmitter emitter, object value, Type type)
             {
-                var typeName = ((Type)value).AssemblyQualifiedName;
-                emitter.Emit(new Scalar(typeName));
+                emitter.Emit(new Scalar(((NonSerializable)value).Text));
             }
         }
     }

YamlDotNet/Serialization/BuilderSkeleton.cs

@@ -21,9 +21,9 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq.Expressions;
 using YamlDotNet.Serialization.Converters;
 using YamlDotNet.Serialization.TypeInspectors;
-using System.Linq.Expressions;
 
 namespace YamlDotNet.Serialization
 {
@@ -45,6 +45,7 @@ internal BuilderSkeleton()
 
             typeConverterFactories = new LazyComponentRegistrationList<Nothing, IYamlTypeConverter>();
             typeConverterFactories.Add(typeof(GuidConverter), _ => new GuidConverter(false));
+            typeConverterFactories.Add(typeof(SystemTypeConverter), _ => new SystemTypeConverter());
 
             typeInspectorFactories = new LazyComponentRegistrationList<ITypeInspector, ITypeInspector>();
         }

YamlDotNet/Serialization/Converters/GuidConverter.cs

@@ -19,7 +19,9 @@
 //  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 //  SOFTWARE.
 
+using System;
 using YamlDotNet.Core;
+using YamlDotNet.Core.Events;
 
 namespace YamlDotNet.Serialization.Converters
 {
@@ -35,22 +37,22 @@ public GuidConverter(bool jsonCompatible)
             this.jsonCompatible = jsonCompatible;
         }
 
-        public bool Accepts(System.Type type)
+        public bool Accepts(Type type)
         {
-            return type == typeof(System.Guid);
+            return type == typeof(Guid);
         }
 
-        public object ReadYaml(Core.IParser parser, System.Type type)
+        public object ReadYaml(IParser parser, Type type)
         {
-            var value = ((Core.Events.Scalar)parser.Current).Value;
+            var value = ((Scalar)parser.Current).Value;
             parser.MoveNext();
-            return new System.Guid(value);
+            return new Guid(value);
         }
 
-        public void WriteYaml(Core.IEmitter emitter, object value, System.Type type)
+        public void WriteYaml(IEmitter emitter, object value, Type type)
         {
-            var guid = (System.Guid)value;
-            emitter.Emit(new Core.Events.Scalar(null, null, guid.ToString("D"), jsonCompatible ? ScalarStyle.DoubleQuoted : ScalarStyle.Any, true, false));
+            var guid = (Guid)value;
+            emitter.Emit(new Scalar(null, null, guid.ToString("D"), jsonCompatible ? ScalarStyle.DoubleQuoted : ScalarStyle.Any, true, false));
         }
     }
 }

YamlDotNet/Serialization/Converters/SystemTypeConverter.cs

@@ -0,0 +1,33 @@
+using System;
+using YamlDotNet.Core;
+using YamlDotNet.Core.Events;
+
+namespace YamlDotNet.Serialization.Converters
+{
+    /// <summary>
+    /// Converter for System.Type.
+    /// </summary>
+    /// <remarks>
+    /// Converts <see cref="System.Type" /> to a scalar containing the assembly qualified name of the type.
+    /// </remarks>
+    public class SystemTypeConverter : IYamlTypeConverter
+    {
+        public bool Accepts(Type type)
+        {
+            return typeof(Type).IsAssignableFrom(type);
+        }
+
+        public object ReadYaml(IParser parser, Type type)
+        {
+            var value = ((Scalar)parser.Current).Value;
+            parser.MoveNext();
+            return Type.GetType(value, throwOnError: true);
+        }
+
+        public void WriteYaml(IEmitter emitter, object value, Type type)
+        {
+            var systemType = (Type)value;
+            emitter.Emit(new Scalar(null, null, systemType.AssemblyQualifiedName, ScalarStyle.Any, true, false));
+        }
+    }
+}

YamlDotNet/Serialization/Deserializer.cs

@@ -107,6 +107,7 @@ public IPropertyDescriptor GetProperty(Type type, object container, string name,
 
                 converters = new List<IYamlTypeConverter>();
                 converters.Add(new GuidConverter(false));
+                converters.Add(new SystemTypeConverter());
 
                 NodeDeserializers = new List<INodeDeserializer>();
                 NodeDeserializers.Add(new YamlConvertibleNodeDeserializer(objectFactory));

YamlDotNet/Serialization/Serializer.cs

@@ -55,6 +55,7 @@ public BackwardsCompatibleConfiguration(SerializationOptions options, INamingCon
 
                 Converters = new List<IYamlTypeConverter>();
                 Converters.Add(new GuidConverter(IsOptionSet(SerializationOptions.JsonCompatible)));
+                Converters.Add(new SystemTypeConverter());
 
                 typeResolver = IsOptionSet(SerializationOptions.DefaultToStaticType)
                     ? (ITypeResolver)new StaticTypeResolver()