Add script property to variable width histogram (#6648)

* Add script property to VariableWidthHistogram

* Add test for VariableWidthHistogram script usage

* Change from script to IScript to match the IMultiTermsAggregation

Author: paulness

src/Nest/Aggregations/Bucket/VariableWidthHistogram/VariableWidthHistogramAggregation.cs

@@ -24,9 +24,12 @@ public interface IVariableWidthHistogramAggregation : IBucketAggregation
 
 		[DataMember(Name = "initial_buffer")]
 		int? InitialBuffer { get; set; }
-		
+
 		[DataMember(Name = "shard_size")]
 		int? ShardSize { get; set; }
+
+		[DataMember(Name = "script")]
+		IScript Script { get; set; }
 	}
 
 	public class VariableWidthHistogramAggregation : BucketAggregationBase, IVariableWidthHistogramAggregation
@@ -42,6 +45,8 @@ public VariableWidthHistogramAggregation(string name) : base(name) { }
 		/// <inheritdoc />
 		public int? ShardSize { get; set; }
 
+		public IScript Script { get; set; }
+
 		internal override void WrapInContainer(AggregationContainer c) => c.VariableWidthHistogram = this;
 	}
 
@@ -53,6 +58,7 @@ public class VariableWidthHistogramAggregationDescriptor<T>
 		int? IVariableWidthHistogramAggregation.Buckets { get; set; }
 		int? IVariableWidthHistogramAggregation.InitialBuffer { get; set; }
 		int? IVariableWidthHistogramAggregation.ShardSize { get; set; }
+		IScript IVariableWidthHistogramAggregation.Script { get; set; }
 
 		/// <inheritdoc cref="IVariableWidthHistogramAggregation.Field" />
 		public VariableWidthHistogramAggregationDescriptor<T> Field(Field field) => Assign(field, (a, v) => a.Field = v);
@@ -68,5 +74,12 @@ public class VariableWidthHistogramAggregationDescriptor<T>
 
 		/// <inheritdoc cref="IVariableWidthHistogramAggregation.ShardSize" />
 		public VariableWidthHistogramAggregationDescriptor<T> ShardSize(int? shardSize) => Assign(shardSize, (a, v) => a.ShardSize = v);
+
+		/// <inheritdoc cref="IVariableWidthHistogramAggregation.Script" />
+		public VariableWidthHistogramAggregationDescriptor<T> Script(string script) => Assign((InlineScript)script, (a, v) => a.Script = v);
+
+		/// <inheritdoc cref="IVariableWidthHistogramAggregation.Script" />
+		public VariableWidthHistogramAggregationDescriptor<T> Script(Func<ScriptDescriptor, IScript> scriptSelector) =>
+			Assign(scriptSelector, (a, v) => a.Script = v?.Invoke(new ScriptDescriptor()));
 	}
 }

tests/Tests/Aggregations/Bucket/VariableWidthHistogram/VariableWidthHistogramUsageTests.cs

@@ -83,4 +83,74 @@ protected override void ExpectResponse(ISearchResponse<Project> response)
 			counts.Meta["foo"].Should().Be("bar");
 		}
 	}
+
+	// hide
+	[SkipVersion("<7.11.0", "Variable width aggregation added in 7.11.0")]
+	public class VariableWidthHistogramWithScriptUsageTests : AggregationUsageTestBase<ReadOnlyCluster>
+	{
+		public VariableWidthHistogramWithScriptUsageTests(ReadOnlyCluster i, EndpointUsage usage) : base(i, usage) { }
+
+		private const string Script = "Math.min(_value, -1)"; // use inline script to force the number of commits to be -1 for all documents
+
+		protected override object AggregationJson => new
+		{
+			commits = new
+			{
+				meta = new
+				{
+					foo = "bar"
+				},
+				variable_width_histogram = new
+				{
+					field = "numberOfCommits",
+					buckets = 2,
+					initial_buffer = 2,
+					shard_size = 100,
+					script = new {
+						source = Script
+					}
+				}
+			}
+		};
+
+		protected override Func<AggregationContainerDescriptor<Project>, IAggregationContainer> FluentAggs => a => a
+			.VariableWidthHistogram("commits", v => v
+				.Field(f => f.NumberOfCommits)
+				.Buckets(2)
+				.InitialBuffer(2)
+				.ShardSize(100)
+				.Script(Script)
+				.Meta(m => m
+					.Add("foo", "bar")
+				));
+
+		protected override AggregationDictionary InitializerAggs =>
+			new VariableWidthHistogramAggregation("commits")
+			{
+				Field = Field<Project>(f => f.NumberOfCommits),
+				Buckets = 2,
+				InitialBuffer = 2,
+				ShardSize = 100,
+				Script = new InlineScript(Script),
+				Meta = new Dictionary<string, object>
+				{
+					{ "foo", "bar" }
+				}
+			};
+
+		protected override void ExpectResponse(ISearchResponse<Project> response)
+		{
+			response.ShouldBeValid();
+			var counts = response.Aggregations.VariableWidthHistogram("commits");
+			counts.Should().NotBeNull();
+			counts.Buckets.Should().HaveCount(1);
+			var firstBucket = counts.Buckets.First();
+			firstBucket.Key.Should().Be(-1);
+			firstBucket.Minimum.Should().Be(-1);
+			firstBucket.Maximum.Should().Be(-1);
+			firstBucket.DocCount.Should().BeGreaterOrEqualTo(1);
+			counts.Meta.Should().NotBeNull().And.HaveCount(1);
+			counts.Meta["foo"].Should().Be("bar");
+		}
+	}
 }