Fix update request not properly inferring doc id

Update was only inferring the doc id from Upsert and not Doc as well.
Additionally, a NullArgumentException was being thrown when specifying the
id property via the ElasticType attribute due to the order in which route
parameters were being validated (checking id before UpdatePathInfo() was
being called).

Closes #806

Author: gmarz

Diff for: src/Nest/DSL/Common/BaseRequest.cs

@@ -42,8 +42,9 @@ TParameters queryString
 			}
 
 			SetRouteParameters(settings, pathInfo);
-
 			UpdatePathInfo(settings, pathInfo);
+			ValidatePathInfo(pathInfo);
+
 			return pathInfo;
 		}
 
@@ -54,6 +55,10 @@ protected virtual void SetRouteParameters(
 
 		}
 
+		protected virtual void ValidatePathInfo(ElasticsearchPathInfo<TParameters> pathInfo)
+		{
+		}
+
 		protected abstract void UpdatePathInfo(IConnectionSettingsValues settings, ElasticsearchPathInfo<TParameters> pathInfo);
 
 		ElasticsearchPathInfo<TParameters> IPathInfo<TParameters>.ToPathInfo(IConnectionSettingsValues settings)

Diff for: src/Nest/DSL/Paths/DocumentPathDescriptor.cs

@@ -13,7 +13,6 @@ protected DocumentPathBase(IndexNameMarker indexName, TypeNameMarker typeName, s
 		}
 	}
 
-
 	public abstract class DocumentPathBase<TParameters, T> : DocumentOptionalPathBase<TParameters, T>
 		where TParameters : FluentRequestParameters<TParameters>, new()
 		where T : class
@@ -24,12 +23,9 @@ protected DocumentPathBase(long id) : base(id) { }
 
 		protected DocumentPathBase(T document) : base(document) { }
 
-		protected override void SetRouteParameters(IConnectionSettingsValues settings, ElasticsearchPathInfo<TParameters> pathInfo)
+		protected override void ValidatePathInfo(ElasticsearchPathInfo<TParameters> pathInfo)
 		{
-			base.SetRouteParameters(settings, pathInfo);
-			pathInfo.Index.ThrowIfNullOrEmpty("index");
-			pathInfo.Type.ThrowIfNullOrEmpty("type");
-			pathInfo.Id.ThrowIfNullOrEmpty("id");
+			DocumentPathValidation.Validate(pathInfo);
 		}
 	}
 
@@ -45,13 +41,21 @@ public abstract class DocumentPathDescriptor<TDescriptor, TParameters, T> : Docu
 		where TParameters : FluentRequestParameters<TParameters>, new()
 		where T : class
 	{
-		protected override void SetRouteParameters(IConnectionSettingsValues settings, ElasticsearchPathInfo<TParameters> pathInfo)
+		protected override void ValidatePathInfo(ElasticsearchPathInfo<TParameters> pathInfo)
+		{
+			DocumentPathValidation.Validate(pathInfo);
+		}
+	}
+
+	internal static class DocumentPathValidation
+	{
+		public static void Validate<TParameters>(ElasticsearchPathInfo<TParameters> pathInfo)
+			where TParameters : FluentRequestParameters<TParameters>, new()
 		{
-			base.SetRouteParameters(settings, pathInfo);
 			pathInfo.Index.ThrowIfNullOrEmpty("index");
 			pathInfo.Type.ThrowIfNullOrEmpty("type");
 			pathInfo.Id.ThrowIfNullOrEmpty("id");
 		}
-
 	}
+
 }

Diff for: src/Nest/DSL/UpdateDescriptor.cs

@@ -32,6 +32,27 @@ public interface IUpdateRequest<TDocument, TPartialDocument> : IDocumentOptional
 		TPartialDocument Doc { get; set; }
 	}
 
+	internal static class UpdateRequestPathInfo
+	{
+		public static void Update<TDocument, TPartialDocument>(
+			IConnectionSettingsValues settings,
+			ElasticsearchPathInfo<UpdateRequestParameters> pathInfo,
+			IUpdateRequest<TDocument, TPartialDocument> self)
+			where TDocument : class
+			where TPartialDocument : class
+		{
+			if (pathInfo.Id.IsNullOrEmpty())
+			{
+				if (self.Doc != null)
+					pathInfo.Id = settings.Inferrer.Id(self.Doc);
+				else if (self.Upsert != null)
+					pathInfo.Id = settings.Inferrer.Id(self.Upsert);
+			}
+
+			pathInfo.HttpMethod = PathInfoHttpMethod.POST;
+		}
+	}
+
 	public class UpdateRequest<TDocument> : UpdateRequest<TDocument, TDocument>
 		where TDocument : class 
 	{
@@ -61,7 +82,7 @@ public UpdateRequest(TDocument idFrom, bool useAsUpsert = false) : base(idFrom)
 
 		protected override void UpdatePathInfo(IConnectionSettingsValues settings, ElasticsearchPathInfo<UpdateRequestParameters> pathInfo)
 		{
-			pathInfo.HttpMethod = PathInfoHttpMethod.POST;
+			UpdateRequestPathInfo.Update(settings, pathInfo, this);
 		}
 
 
@@ -73,7 +94,6 @@ protected override void UpdatePathInfo(IConnectionSettingsValues settings, Elast
 		public TPartialDocument Doc { get; set; }
 	}
 
-
 	public partial class UpdateDescriptor<TDocument,TPartialDocument> 
 		: DocumentPathDescriptor<UpdateDescriptor<TDocument, TPartialDocument>, UpdateRequestParameters, TDocument>
 		, IUpdateRequest<TDocument, TPartialDocument> 
@@ -164,12 +184,7 @@ public UpdateDescriptor<TDocument,TPartialDocument> Fields(params Expression<Fun
 
 		protected override void UpdatePathInfo(IConnectionSettingsValues settings, ElasticsearchPathInfo<UpdateRequestParameters> pathInfo)
 		{
-			if (pathInfo.Id.IsNullOrEmpty())
-			{
-				pathInfo.Id = settings.Inferrer.Id(Self.Upsert);
-			}
-
-			pathInfo.HttpMethod = PathInfoHttpMethod.POST;
+			UpdateRequestPathInfo.Update(settings, pathInfo, this);
 		}
 	}
 }

Diff for: src/Tests/Nest.Tests.Unit/Nest.Tests.Unit.csproj

@@ -363,6 +363,7 @@
     <Compile Include="QueryParsers\Visitor\VisitorTests.cs" />
     <Compile Include="Reproduce\Reproduce646Tests.cs" />
     <Compile Include="Reproduce\Reproduce579Tests.cs" />
+    <Compile Include="Reproduce\Reproduce806Tests.cs" />
     <Compile Include="Search\Fields\FieldsTests.cs" />
     <Compile Include="Search\Filter\Modes\ConditionlessFilterJson.cs" />
     <Compile Include="Search\Filter\Modes\FilterModesTests.cs" />

Diff for: src/Tests/Nest.Tests.Unit/Reproduce/Reproduce806Tests.cs

@@ -0,0 +1,26 @@
+using NUnit.Framework;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Nest.Tests.Unit.Reproduce
+{
+	[ElasticType(Name="mypoco", IdProperty="Code")]
+	public class MyPoco
+	{
+		[ElasticProperty(Name="code")]
+		public string Code { get; set; }
+	}
+
+	[TestFixture]
+	public class Reproduce806Tests : BaseJsonTests
+	{
+		[Test]
+		public void IdPropertyAttributeCausesArgumentNullException()
+		{
+			var r = _client.Update<MyPoco>(d => d.DocAsUpsert().Doc(new MyPoco { Code = "1" }));
+		}
+	}
+}