refact: batch delete operation serialization (#640)

Author: aallam

src/main/scala/algolia/AlgoliaDsl.scala

@@ -27,7 +27,9 @@ package algolia
 
 import algolia.definitions._
 import algolia.dsl._
+import algolia.inputs.DeleteObjectOperation
 import algolia.objects._
+import org.json4s
 import org.json4s.JsonAST._
 import org.json4s.JsonDSL._
 import org.json4s.{CustomSerializer, FieldSerializer, Formats, JField}
@@ -92,6 +94,9 @@ object AlgoliaDsl extends AlgoliaDsl {
       new AlternativesSerializer +
       new FieldSerializer[IndexSettings](
         deserializer = numericAttributesToIndexDeserializer
+      ) +
+      new FieldSerializer[DeleteObjectOperation[JValue]](
+        serializer = deleteObjectOperationSerializer
       )
 
   val searchableAttributesUnordered: Regex = """^unordered\(([\w-\\.]+)\)$""".r
@@ -417,6 +422,12 @@ object AlgoliaDsl extends AlgoliaDsl {
       )
   }
 
+  def deleteObjectOperationSerializer
+      : PartialFunction[(String, Any), Option[(String, Any)]] = {
+    case Tuple2("objectID", objectID) =>
+      Some("body" -> ("objectID" -> objectID))
+  }
+
   case object forwardToSlaves extends ForwardToReplicas
 
   case object forwardToReplicas extends ForwardToReplicas

src/test/scala/algolia/dsl/BatchTest.scala

@@ -188,11 +188,11 @@ class BatchTest extends AlgoliaTest {
             |   "requests":[
             |     {
             |       "indexName":"test1",
-            |       "objectID":"1",
+            |       "body":{"objectID":"1"},
             |       "action":"deleteObject"
             |     },{
             |       "indexName":"test2",
-            |       "objectID":"2",
+            |       "body":{"objectID":"2"},
             |       "action":"deleteObject"
             |     }
             |   ]

src/test/scala/algolia/dsl/DeleteObjectTest.scala

@@ -61,10 +61,10 @@ class DeleteObjectTest extends AlgoliaTest {
             | {
             |   "requests":[
             |     {
-            |       "objectID":"1",
+            |       "body":{"objectID":"1"},
             |       "action":"deleteObject"
             |     },{
-            |       "objectID":"2",
+            |       "body":{"objectID":"2"},
             |       "action":"deleteObject"
             |     }
             |   ]