Add global highlight_query (#4863) (#4867)

This commit adds a global highlight_query to
highlighter options.

Closes #4862

Co-authored-by: Russ Cam <russ.cam@elastic.co>

Author: github-actions[bot]

docs/search/request/highlighting-usage.asciidoc

@@ -36,6 +36,12 @@ s => s
     .PreTags("<tag1>")
     .PostTags("</tag1>")
     .Encoder(HighlighterEncoder.Html)
+    .HighlightQuery(q => q
+        .Match(m => m
+            .Field(f => f.Name.Suffix("standard"))
+            .Query("Upton Sons Shield Rice Rowe Roberts")
+        )
+    )
     .Fields(
         fs => fs
             .Field(p => p.Name.Suffix("standard"))
@@ -90,6 +96,11 @@ new SearchRequest<Project>
         PreTags = new[] { "<tag1>" },
         PostTags = new[] { "</tag1>" },
         Encoder = HighlighterEncoder.Html,
+        HighlightQuery = new MatchQuery
+        {
+            Query = "Upton Sons Shield Rice Rowe Roberts",
+            Field = "name.standard"
+        },
         Fields = new Dictionary<Field, IHighlightField>
         {
             {
@@ -155,6 +166,13 @@ new SearchRequest<Project>
       "</tag1>"
     ],
     "encoder": "html",
+    "highlight_query": {
+      "match": {
+        "name.standard": {
+          "query": "Upton Sons Shield Rice Rowe Roberts"
+        }
+      }
+    },
     "fields": {
       "name.standard": {
         "type": "plain",

src/Nest/Search/Search/Highlighting/Highlight.cs

@@ -73,6 +73,12 @@ public interface IHighlight
 		[DataMember(Name ="fragment_size")]
 		int? FragmentSize { get; set; }
 
+		/// <summary>
+		/// The query to use for highlighting
+		/// </summary>
+		[DataMember(Name = "highlight_query")]
+		QueryContainer HighlightQuery { get; set; }
+
 		[DataMember(Name ="max_fragment_length")]
 		int? MaxFragmentLength { get; set; }
 
@@ -169,6 +175,9 @@ public class Highlight : IHighlight
 		/// <inheritdoc/>
 		public int? FragmentSize { get; set; }
 
+		/// <inheritdoc/>
+		public QueryContainer HighlightQuery { get; set; }
+
 		/// <inheritdoc/>
 		public int? MaxFragmentLength { get; set; }
 
@@ -214,6 +223,7 @@ public class HighlightDescriptor<T> : DescriptorBase<HighlightDescriptor<T>, IHi
 		HighlighterFragmenter? IHighlight.Fragmenter { get; set; }
 		int? IHighlight.FragmentOffset { get; set; }
 		int? IHighlight.FragmentSize { get; set; }
+		QueryContainer IHighlight.HighlightQuery { get; set; }
 		int? IHighlight.MaxFragmentLength { get; set; }
 		int? IHighlight.NoMatchSize { get; set; }
 		int? IHighlight.NumberOfFragments { get; set; }
@@ -253,6 +263,10 @@ public HighlightDescriptor<T> Fields(params Func<HighlightFieldDescriptor<T>, IH
 		/// <inheritdoc cref="IHighlight.FragmentSize" />
 		public HighlightDescriptor<T> FragmentSize(int? fragmentSize) => Assign(fragmentSize, (a, v) => a.FragmentSize = v);
 
+		/// <inheritdoc cref="IHighlight.HighlightQuery" />
+		public HighlightDescriptor<T> HighlightQuery(Func<QueryContainerDescriptor<T>, QueryContainer> query) =>
+			Assign(query, (a, v) => a.HighlightQuery = v?.Invoke(new QueryContainerDescriptor<T>()));
+
 		/// <inheritdoc cref="IHighlight.NumberOfFragments" />
 		public HighlightDescriptor<T> NumberOfFragments(int? numberOfFragments) => Assign(numberOfFragments, (a, v) => a.NumberOfFragments = v);
 

tests/Tests/Search/Request/HighlightingUsageTests.cs

@@ -46,6 +46,18 @@ public HighlightingUsageTests(ReadOnlyCluster cluster, EndpointUsage usage) : ba
 				pre_tags = new[] { "<tag1>" },
 				post_tags = new[] { "</tag1>" },
 				encoder = "html",
+				highlight_query = new
+				{
+					match = new Dictionary<string, object>
+					{
+						{
+							"name.standard", new Dictionary<string, object>
+							{
+								{ "query", "Upton Sons Shield Rice Rowe Roberts" }
+							}
+						}
+					}
+				},
 				fields = new Dictionary<string, object>
 				{
 					{
@@ -124,6 +136,12 @@ public HighlightingUsageTests(ReadOnlyCluster cluster, EndpointUsage usage) : ba
 				.PreTags("<tag1>")
 				.PostTags("</tag1>")
 				.Encoder(HighlighterEncoder.Html)
+				.HighlightQuery(q => q
+					.Match(m => m
+						.Field(f => f.Name.Suffix("standard"))
+						.Query("Upton Sons Shield Rice Rowe Roberts")
+					)
+				)
 				.Fields(
 					fs => fs
 						.Field(p => p.Name.Suffix("standard"))
@@ -173,6 +191,11 @@ public HighlightingUsageTests(ReadOnlyCluster cluster, EndpointUsage usage) : ba
 					PreTags = new[] { "<tag1>" },
 					PostTags = new[] { "</tag1>" },
 					Encoder = HighlighterEncoder.Html,
+					HighlightQuery = new MatchQuery
+					{
+						Query = "Upton Sons Shield Rice Rowe Roberts",
+						Field = "name.standard"
+					},
 					Fields = new Dictionary<Field, IHighlightField>
 					{
 						{