Add DocValueFields to TopHits Aggregation (#3292)

closes #3274

Author: russcam

docs/aggregations/metric/top-hits/top-hits-aggregation-usage.asciidoc

@@ -61,11 +61,15 @@ a => a
                     .ScriptField("commit_factor", sf => sf
                         .Source("doc['numberOfCommits'].value * 2")
 
+                    )
+
+                )
+                .DocValueFields(d => d
+                    .Field(p => p.State)
                 )
             )
         )
     )
-)
 ----
 
 ==== Object Initializer syntax example
@@ -104,15 +108,17 @@ new TermsAggregation("states")
                     { Field<Project>(p => p.Description), new HighlightField() }
                 }
             },
-            ScriptFields = new ScriptFields{
+            ScriptFields = new ScriptFields
             {
-                "commit_factor", new ScriptField
                 {
-                    Script = new InlineScript("doc['numberOfCommits'].value * 2")
-                }
-            }
+                    "commit_factor", new ScriptField
+                    {
+                        Script = new InlineScript("doc['numberOfCommits'].value * 2")
+                    }
+                },
+            },
+            DocValueFields = Infer.Fields<Project>(f => f.State)
         }
-    }
 }
 ----
 
@@ -170,7 +176,10 @@ new TermsAggregation("states")
                 "source": "doc['numberOfCommits'].value * 2"
               }
             }
-          }
+          },
+          "docvalue_fields": [
+            "state"
+          ]
         }
       }
     }

src/CodeGeneration/DocGenerator/StringExtensions.cs

@@ -210,6 +210,10 @@ public static string[] SplitOnNewLines(this string input, StringSplitOptions opt
 									}" },
 			{ "LineStringCoordinates", @"new [] { new [] {38.897676, -77.03653}, new [] {38.889939, -77.009051} }" },
 			{ "PointCoordinates", "new[] { 38.897676, -77.03653 }" },
+			{ "this._polygonCoordinates", @"new[]{
+										new []{ new [] {10.0, -17.0}, new [] {15.0, 16.0}, new [] {0.0, 12.0}, new [] {-15.0, 16.0}, new [] {-10.0, -17.0},new [] {10.0, -17.0}},
+										new []{ new [] {8.2, 18.2}, new [] {8.2, -18.8}, new [] {-8.8, -10.8}, new [] {8.8, 18.2}}
+									}" },
 		};
 
 		public static bool TryGetJsonForAnonymousType(this string anonymousTypeString, out string json)

src/Nest/Aggregations/Metric/TopHits/TopHitsAggregation.cs

@@ -33,6 +33,9 @@ public interface ITopHitsAggregation : IMetricAggregation
 		[JsonProperty("stored_fields")]
 		Fields StoredFields { get; set; }
 
+		[JsonProperty("docvalue_fields")]
+		Fields DocValueFields { get; set; }
+
 		[JsonProperty("version")]
 		bool? Version { get; set; }
 
@@ -52,6 +55,7 @@ public class TopHitsAggregation : MetricAggregationBase, ITopHitsAggregation
 		public Fields StoredFields { get; set; }
 		public bool? Version { get; set; }
 		public bool? TrackScores { get; set; }
+		public Fields DocValueFields { get; set; }
 
 		internal TopHitsAggregation() { }
 
@@ -85,6 +89,8 @@ public class TopHitsAggregationDescriptor<T>
 
 		bool? ITopHitsAggregation.TrackScores { get; set; }
 
+		Fields ITopHitsAggregation.DocValueFields { get; set; }
+
 		public TopHitsAggregationDescriptor<T> From(int? from) => Assign(a => a.From = from);
 
 		public TopHitsAggregationDescriptor<T> Size(int? size) => Assign(a => a.Size = size);
@@ -112,5 +118,10 @@ public TopHitsAggregationDescriptor<T> StoredFields(Func<FieldsDescriptor<T>, IP
 		public TopHitsAggregationDescriptor<T> Version(bool? version = true) => Assign(a => a.Version = version);
 
 		public TopHitsAggregationDescriptor<T> TrackScores(bool? trackScores = true) => Assign(a => a.TrackScores = trackScores);
+
+		public TopHitsAggregationDescriptor<T> DocValueFields(Func<FieldsDescriptor<T>, IPromise<Fields>> fields) =>
+			Assign(a => a.DocValueFields = fields?.Invoke(new FieldsDescriptor<T>())?.Value);
+
+		public TopHitsAggregationDescriptor<T> DocValueFields(Fields fields) => Assign(a => a.DocValueFields = fields);
 	}
 }

src/Tests/Aggregations/Metric/TopHits/TopHitsAggregationUsageTests.cs

@@ -78,7 +78,8 @@ public TopHitsAggregationUsageTests(ReadOnlyCluster i, EndpointUsage usage) : ba
 										source = "doc['numberOfCommits'].value * 2",
 									}
 								}
-							}
+							},
+							docvalue_fields = new [] { "state" }
 						}
 					}
 				}
@@ -127,11 +128,15 @@ public TopHitsAggregationUsageTests(ReadOnlyCluster i, EndpointUsage usage) : ba
 								.ScriptField("commit_factor", sf => sf
 									.Source("doc['numberOfCommits'].value * 2")
 
+								)
+
+							)
+							.DocValueFields(d => d
+								.Field(p => p.State)
 							)
 						)
 					)
-				)
-			);
+				);
 
 		protected override AggregationDictionary InitializerAggs =>
 			new TermsAggregation("states")
@@ -166,15 +171,17 @@ public TopHitsAggregationUsageTests(ReadOnlyCluster i, EndpointUsage usage) : ba
 								{ Field<Project>(p => p.Description), new HighlightField() }
 							}
 						},
-						ScriptFields = new ScriptFields{
+						ScriptFields = new ScriptFields
 						{
-							"commit_factor", new ScriptField
 							{
-								Script = new InlineScript("doc['numberOfCommits'].value * 2")
-							}
-						}
+								"commit_factor", new ScriptField
+								{
+									Script = new InlineScript("doc['numberOfCommits'].value * 2")
+								}
+							},
+						},
+						DocValueFields = Infer.Fields<Project>(f => f.State)
 					}
-				}
 			};
 
 		protected override void ExpectResponse(ISearchResponse<Project> response)