Mark PositionOffsetGap as obsolete in favor of PositionIncrementGap

Closes #2027

Author: gmarz

src/Nest/Mapping/Types/Core/String/StringAttribute.cs

@@ -1,4 +1,6 @@
-namespace Nest
+using System;
+
+namespace Nest
 {
 	public class StringAttribute : ElasticsearchPropertyAttributeBase, IStringProperty
 	{
@@ -14,7 +16,9 @@ public class StringAttribute : ElasticsearchPropertyAttributeBase, IStringProper
         string IStringProperty.SearchAnalyzer { get; set; }
         bool? IStringProperty.IncludeInAll { get; set; }
         int? IStringProperty.IgnoreAbove { get; set; }
-        int? IStringProperty.PositionOffsetGap { get; set; }
+		[Obsolete("Scheduled to be removed in 5.0. Use PositionIncrementGap instead.")]
+        int? IStringProperty.PositionOffsetGap { get { return Self.PositionIncrementGap; } set { Self.PositionIncrementGap = value; } }
+		int? IStringProperty.PositionIncrementGap { get; set; }
 		IStringFielddata IStringProperty.Fielddata { get; set; }
 
 		public string Analyzer { get { return Self.Analyzer; } set { Self.Analyzer = value; } }
@@ -24,7 +28,9 @@ public class StringAttribute : ElasticsearchPropertyAttributeBase, IStringProper
 		public FieldIndexOption Index { get { return Self.Index.GetValueOrDefault(); } set { Self.Index = value; } }
 		public IndexOptions IndexOptions { get { return Self.IndexOptions.GetValueOrDefault(); } set { Self.IndexOptions = value; } }
 		public string NullValue { get { return Self.NullValue; } set { Self.NullValue = value; } }
-		public int PositionOffsetGap { get { return Self.PositionOffsetGap.GetValueOrDefault(); } set { Self.PositionOffsetGap = value; } }
+		[Obsolete("Scheduled to be removed in 5.0. Use PositionIncrementGap instead.")]
+		public int PositionOffsetGap { get { return Self.PositionIncrementGap.GetValueOrDefault(); } set { Self.PositionIncrementGap = value; } }
+		public int PositionIncrementGap { get { return Self.PositionIncrementGap.GetValueOrDefault(); } set { Self.PositionIncrementGap = value; } }
 		public string SearchAnalyzer { get { return Self.SearchAnalyzer; } set { Self.SearchAnalyzer = value; } }
 		public TermVectorOption TermVector { get { return Self.TermVector.GetValueOrDefault(); } set { Self.TermVector = value; } }
 

src/Nest/Mapping/Types/Core/String/StringProperty.cs

@@ -36,9 +36,13 @@ public interface IStringProperty : IProperty
 		[JsonProperty("ignore_above")]
 		int? IgnoreAbove { get; set; }
 
-		[JsonProperty("position_offset_gap")]
+		[JsonIgnore]
+		[Obsolete("Scheduled to be removed in 5.0. Use PositionIncrementGap instead.")]
 		int? PositionOffsetGap { get; set; }
 
+		[JsonProperty("position_increment_gap")]
+		int? PositionIncrementGap { get; set; }
+
 		[JsonProperty("fielddata")]
 		IStringFielddata Fielddata { get; set; }
 	}
@@ -57,11 +61,14 @@ public StringProperty() : base("string") { }
 		public string SearchAnalyzer { get; set; }
 		public bool? IncludeInAll { get; set; }
 		public int? IgnoreAbove { get; set; }
-		public int? PositionOffsetGap { get; set; }
+		[Obsolete("Scheduled to be removed in 5.0. Use PositionIncrementGap instead.")]
+		public int? PositionOffsetGap { get { return PositionIncrementGap; } set { PositionIncrementGap = value; } }
+		public int? PositionIncrementGap { get; set; }
 		public IStringFielddata Fielddata { get; set; }
+
 	}
 
-	public class StringPropertyDescriptor<T> 
+	public class StringPropertyDescriptor<T>
 		: PropertyDescriptorBase<StringPropertyDescriptor<T>, IStringProperty, T>, IStringProperty
 		where T : class
 	{
@@ -75,7 +82,9 @@ public class StringPropertyDescriptor<T>
 		string IStringProperty.SearchAnalyzer { get; set; }
 		bool? IStringProperty.IncludeInAll { get; set; }
 		int? IStringProperty.IgnoreAbove { get; set; }
-		int? IStringProperty.PositionOffsetGap { get; set; }
+		[Obsolete("Scheduled to be removed in 5.0. Use PositionIncrementGap instead.")]
+		int? IStringProperty.PositionOffsetGap { get { return Self.PositionIncrementGap; } set { Self.PositionIncrementGap = value; } }
+		int? IStringProperty.PositionIncrementGap { get; set; }
 		IStringFielddata IStringProperty.Fielddata { get; set; }
 
 		public StringPropertyDescriptor() : base("string") { }
@@ -105,9 +114,12 @@ public StringPropertyDescriptor() : base("string") { }
 
 		public StringPropertyDescriptor<T> IncludeInAll(bool includeInAll = true) => Assign(a => a.IncludeInAll = includeInAll);
 
-		public StringPropertyDescriptor<T> PositionOffsetGap(int positionOffsetGap) => Assign(a => a.PositionOffsetGap = positionOffsetGap);
+		[Obsolete("Scheduled to be removed in 5.0. Use PositionIncrementGap() instead.")]
+		public StringPropertyDescriptor<T> PositionOffsetGap(int positionOffsetGap) => Assign(a => a.PositionIncrementGap = positionOffsetGap);
+
+		public StringPropertyDescriptor<T> PositionIncrementGap(int? positionIncrementGap) => Assign(a => a.PositionIncrementGap = positionIncrementGap);
 
 		public StringPropertyDescriptor<T> Fielddata(Func<StringFielddataDescriptor, IStringFielddata> selector) =>
 			Assign(a => a.Fielddata = selector?.Invoke(new StringFielddataDescriptor()));
 	}
-}
+}

src/Tests/Mapping/Types/Core/String/StringMappingTests.cs

@@ -14,6 +14,7 @@ public class StringTest
 			Index = FieldIndexOption.NotAnalyzed,
 			IndexOptions = IndexOptions.Offsets,
 			NullValue = "na",
+			// Purposely setting this obsolete property to ensure it serializes as position_increment_gap
 			PositionOffsetGap = 5,
 			SearchAnalyzer = "mysearchanalyzer",
 			Similarity = SimilarityOption.BM25,
@@ -48,7 +49,7 @@ public class StringMappingTests : TypeMappingTestBase<StringTest>
 					index = "not_analyzed",
 					index_options = "offsets",
 					null_value = "na",
-					position_offset_gap = 5,
+					position_increment_gap = 5,
 					search_analyzer = "mysearchanalyzer",
 					similarity = "BM25",
 					store = true,
@@ -57,11 +58,11 @@ public class StringMappingTests : TypeMappingTestBase<StringTest>
 				minimal = new
 				{
 					type = "string"
-				},			
+				},
                 inferred = new
 				{
 					type = "string"
-				},			
+				},
                 @char = new
 				{
 					type = "string"
@@ -84,7 +85,7 @@ public class StringMappingTests : TypeMappingTestBase<StringTest>
 				.Index(FieldIndexOption.NotAnalyzed)
 				.IndexOptions(IndexOptions.Offsets)
 				.NullValue("na")
-				.PositionOffsetGap(5)
+				.PositionIncrementGap(5)
 				.SearchAnalyzer("mysearchanalyzer")
 				.Similarity(SimilarityOption.BM25)
 				.Store(true)