fix #2119 in master, make similarity on per field mapping a string

src/Nest/Mapping/AttributeBased/ElasticsearchCorePropertyAttributeBase.cs

@@ -12,10 +12,18 @@ public abstract class ElasticsearchCorePropertyAttributeBase : ElasticsearchProp
 
 		bool? ICoreProperty.Store { get; set; }
 		IProperties ICoreProperty.Fields { get; set; }
-		SimilarityOption? ICoreProperty.Similarity { get; set; }
 		Fields ICoreProperty.CopyTo { get; set; }
 
-		public SimilarityOption Similarity { get { return Self.Similarity.GetValueOrDefault(); } set { Self.Similarity = value; } }
+		Union<SimilarityOption, string> ICoreProperty.Similarity { get; set; }
+		public string Similarity {
+			set { Self.Similarity = value; }
+			get
+			{
+				var s = Self.Similarity;
+				if (s == null) return null;
+				return s.Match(f => f.GetStringValue(), str => str);
+			}
+		}
 		public bool Store { get { return Self.Store.GetValueOrDefault(); } set { Self.Store = value; } }
 
 		protected ElasticsearchCorePropertyAttributeBase(string typeName) : base(typeName)

src/Nest/Mapping/Types/CorePropertyBase.cs

@@ -13,7 +13,7 @@ public interface ICoreProperty : IProperty
 		IProperties Fields { get; set; }
 
 		[JsonProperty("similarity")]
-		SimilarityOption? Similarity { get; set; }
+		Union<SimilarityOption, string> Similarity { get; set; }
 
 		[JsonProperty("copy_to")]
 		Fields CopyTo { get; set; }
@@ -27,7 +27,7 @@ protected CorePropertyBase(TypeName typeName) : base(typeName)
 
 		public Fields CopyTo { get; set; }
 		public IProperties Fields { get; set; }
-		public SimilarityOption? Similarity { get; set; }
+		public Union<SimilarityOption, string> Similarity { get; set; }
 		public bool? Store { get; set; }
 	}
 }

src/Nest/Mapping/Types/CorePropertyDescriptorBase.cs

@@ -9,7 +9,7 @@ public abstract class CorePropertyDescriptorBase<TDescriptor, TInterface, T>
 		where T : class
 	{
 		bool? ICoreProperty.Store { get; set; }
-		SimilarityOption? ICoreProperty.Similarity { get; set; }
+		Union<SimilarityOption, string> ICoreProperty.Similarity { get; set; }
 		Fields ICoreProperty.CopyTo { get; set; }
 		IProperties ICoreProperty.Fields { get; set; }
 
@@ -21,6 +21,8 @@ protected CorePropertyDescriptorBase(string type) : base(type) {}
 
 		public TDescriptor Similarity(SimilarityOption similarity) => Assign(a => a.Similarity = similarity);
 
+		public TDescriptor Similarity(string similarity) => Assign(a => a.Similarity = similarity);
+
 		public TDescriptor CopyTo(Func<FieldsDescriptor<T>, IPromise<Fields>> fields) => Assign(a => a.CopyTo = fields?.Invoke(new FieldsDescriptor<T>())?.Value);
 	}
 }

src/Tests/ClientConcepts/HighLevel/Mapping/AutoMap.doc.cs

@@ -173,7 +173,7 @@ public void UsingAutoMap()
 											{
 												type = "keyword"
 											}
-									},
+										},
 										type = "text"
 									},
 									hours = new
@@ -192,7 +192,7 @@ public void UsingAutoMap()
 											{
 												type = "keyword"
 											}
-									},
+										},
 										type = "text"
 									},
 									salary = new
@@ -209,10 +209,10 @@ public void UsingAutoMap()
 									keyword = new
 									{
 										type = "keyword"
-							}
+									}
 								},
 								type = "text"
-						}
+							}
 						}
 					},
 					employee = new
@@ -236,7 +236,7 @@ public void UsingAutoMap()
 									{
 										type = "keyword"
 									}
-							},
+								},
 								type = "text"
 							},
 							hours = new
@@ -255,7 +255,7 @@ public void UsingAutoMap()
 									{
 										type = "keyword"
 									}
-							},
+								},
 								type = "text"
 							},
 							salary = new
@@ -356,7 +356,7 @@ public void OverridingAutoMappedProperties()
 		[ElasticsearchType(Name = "company")]
 		public class CompanyWithAttributes
 		{
-			[Keyword(NullValue = "null", Similarity = SimilarityOption.BM25)]
+			[Keyword(NullValue = "null", Similarity = "BM25")]
 			public string Name { get; set; }
 
 			[Text(Name = "office_hours")]
@@ -429,7 +429,7 @@ public void UsingAutoMapWithAttributes()
 											{
 												type = "keyword"
 											}
-									},
+										},
 										type = "text"
 									},
 									hours = new
@@ -448,7 +448,7 @@ public void UsingAutoMapWithAttributes()
 											{
 												type = "keyword"
 											}
-									},
+										},
 										type = "text"
 									},
 									salary = new
@@ -503,7 +503,7 @@ public void UsingAutoMapWithAttributes()
 											{
 												type = "keyword"
 											}
-									},
+										},
 										type = "text"
 									},
 									hours = new
@@ -522,7 +522,7 @@ public void UsingAutoMapWithAttributes()
 											{
 												type = "keyword"
 											}
-									},
+										},
 										type = "text"
 									},
 									salary = new
@@ -682,7 +682,7 @@ public void OverridingAutoMappedAttributes()
 											{
 												type = "keyword"
 											}
-									},
+										},
 										type = "text"
 									},
 									salary = new
@@ -785,12 +785,12 @@ public void IgnoringProperties()
 									keyword = new
 									{
 										type = "keyword"
+									}
+								}
 							}
 						}
 					}
 				}
-					}
-				}
 			};
 
 			var settings = WithConnectionSettings(s => s
@@ -960,7 +960,7 @@ public void PutMappingAlsoAdheresToMaxRecursion()
 		//endhide
 
 		/**[float]
-         * == Applying conventions through the Visitor pattern
+		 * == Applying conventions through the Visitor pattern
 		 * It is also possible to apply a transformation on all or specific properties.
 		 *
 		 * `.AutoMap()` internally implements the https://en.wikipedia.org/wiki/Visitor_pattern[visitor pattern]. The default visitor, `NoopPropertyVisitor`,

src/Tests/Mapping/Types/Core/Binary/BinaryMappingTests.cs

@@ -8,7 +8,7 @@ public class BinaryTest
 		[Binary(
 			DocValues = true,
 			IndexName = "myindex",
-			Similarity = SimilarityOption.Classic,
+			Similarity = "classic",
 			Store = true)]
 		public string Full { get; set; }
 

src/Tests/Mapping/Types/Core/Boolean/BooleanMappingTests.cs

@@ -8,7 +8,7 @@ public class BooleanTest
 		[Boolean(
 			DocValues = false,
 			IndexName = "myindex",
-			Similarity = SimilarityOption.BM25,
+			Similarity = "BM25",
 			Index = false,
 			Store = true)]
 		public bool Full { get; set; }

src/Tests/Mapping/Types/Core/Date/DateMappingTests.cs

@@ -8,7 +8,7 @@ public class DateTest
 		[Date(
 			DocValues = true,
 			IndexName = "myindex",
-			Similarity = SimilarityOption.Classic,
+			Similarity = "classic",
 			Store = true,
 			Index = false,
 			Boost = 1.2,
@@ -22,9 +22,9 @@ public class DateTest
 		[Date]
 		public DateTime Minimal { get; set; }
 
-        public DateTime Inferred { get; set; }
+		public DateTime Inferred { get; set; }
 
-        public DateTimeOffset InferredOffset { get; set; }
+		public DateTimeOffset InferredOffset { get; set; }
 	}
 
 	public class DateMappingTests : TypeMappingTestBase<DateTest>
@@ -52,14 +52,14 @@ public class DateMappingTests : TypeMappingTestBase<DateTest>
 				{
 					type = "date"
 				},
-                inferred = new
-                {
-                    type = "date"
-                },
-                inferredOffset = new
-                {
-                    type = "date"
-                }
+				inferred = new
+				{
+					type = "date"
+				},
+				inferredOffset = new
+				{
+					type = "date"
+				}
 			}
 		};
 
@@ -81,11 +81,11 @@ public class DateMappingTests : TypeMappingTestBase<DateTest>
 			.Date(d => d
 				.Name(o => o.Minimal)
 			)
-            .Date(d => d
+			.Date(d => d
 				.Name(o => o.Inferred)
 			)
-            .Date(d => d
-                .Name(o => o.InferredOffset)
-            );
+			.Date(d => d
+				.Name(o => o.InferredOffset)
+			);
 	}
 }

src/Tests/Mapping/Types/Core/Number/NumberMappingTests.cs

@@ -8,7 +8,7 @@ public class NumberTest
 		[Number(
 			DocValues = true,
 			IndexName = "myindex",
-			Similarity = SimilarityOption.Classic,
+			Similarity = "classic",
 			Store = true,
 			Index = false,
 			Boost = 1.5,

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

@@ -17,7 +17,7 @@ public class StringTest
 			NullValue = "na",
 			PositionIncrementGap = 5,
 			SearchAnalyzer = "mysearchanalyzer",
-			Similarity = SimilarityOption.BM25,
+			Similarity = "BM25",
 			Store = true,
 			TermVector = TermVectorOption.WithPositionsOffsets)]
 		public string Full { get; set; }

src/Tests/Mapping/Types/Core/Text/TextMappingTests.cs

@@ -16,15 +16,15 @@ public class TextTest
 			PositionIncrementGap = 5,
 			SearchAnalyzer = "mysearchanalyzer",
 			SearchQuoteAnalyzer = "mysearchquoteanalyzer",
-			Similarity = SimilarityOption.Classic,
+			Similarity = "classic",
 			Store = true,
 			Norms = false)]
 		public string Full { get; set; }
 
 		[Text]
 		public string Minimal { get; set; }
 
-        public string Inferred { get; set; }
+		public string Inferred { get; set; }
 	}
 
 	public class TextMappingTests : TypeMappingTestBase<TextTest>
@@ -56,7 +56,7 @@ public class TextMappingTests : TypeMappingTestBase<TextTest>
 				{
 					type = "text"
 				},
-                inferred = new
+				inferred = new
 				{
 					type = "text",
 					fields = new

src/Tests/tests.yaml

@@ -1,5 +1,5 @@
 # mode either u (unit test), i (integration test) or m (mixed mode)
-mode: i
+mode: u
 # the elasticsearch version that should be started
 # Can be a snapshot version of sonatype or "latest" to get the latest snapshot of sonatype
 elasticsearch_version: 5.0.0-alpha5