Merge pull request #1491 from elastic/fix/guid-mapfromattributes

fix #1381  mapfromattributes now maps Guid to strings automatically

Author: gmarz

src/Nest/Resolvers/Writers/TypeMappingWriter.cs

@@ -300,6 +300,8 @@ private string GetElasticsearchType(FieldType? fieldType)
 						return FieldType.Date;
 					case "Boolean":
 						return FieldType.Boolean;
+					case "Guid":
+						return FieldType.String;
 				}
 			}
 			else

src/Tests/Nest.Tests.Integration/Mapping/MapFromAttributeTests.cs

@@ -14,6 +14,7 @@ public class MapFromAttributeTests : IntegrationTests
 	{
 		class MapFromAttributeObject
 		{
+			public Guid Id { get; set; }
 			public string Name { get; set; }
 			[ElasticProperty(Type = FieldType.Nested, IncludeInParent = true)]
 			public List<NestedObject> NestedObjects { get; set; }
@@ -36,6 +37,8 @@ public void InlcudeInParent()
 			var typeMapping = this.Client.GetMapping<MapFromAttributeObject>(i => i.Type("mapfromattributeobject"));
 			typeMapping.Should().NotBeNull();
 
+			typeMapping.Mapping.Properties["id"].Type.Name.Should().Be("string");
+
 			typeMapping.Mapping.Properties["nestedObjects"].Type.Name.Should().Be("nested");
 			typeMapping.Mapping.Properties["nestedObjectsDontIncludeInParent"].Type.Name.Should().Be("nested");
 			var nestedObject = typeMapping.Mapping.Properties["nestedObjects"] as NestedObjectMapping;