support bulk delete requests

lib/elasticsearch/indexing/bulk.ex

@@ -48,10 +48,23 @@ defmodule Elasticsearch.Index.Bulk do
       {"title":null,"doctype":{"name":"post"},"author":null}
       \"\"\"
 
+      iex> Bulk.encode!(Cluster, %Post{id: "my-id"}, "my-index", "delete")
+      \"\"\"
+      {"delete":{"_index":"my-index","_id":"my-id"}}
+      \"\"\"
+
       iex> Bulk.encode!(Cluster, 123, "my-index")
       ** (Protocol.UndefinedError) protocol Elasticsearch.Document not implemented for 123 of type Integer
   """
-  def encode!(cluster, struct, index, action \\ "create") do
+  def encode!(cluster, struct, index, action \\ "create")
+
+  def encode!(cluster, struct, index, "delete") do
+    config = Cluster.Config.get(cluster)
+    header = header(config, "delete", index, struct)
+    "#{header}\n"
+  end
+
+  def encode!(cluster, struct, index, action) do
     config = Cluster.Config.get(cluster)
     header = header(config, action, index, struct)
 

test/elasticsearch/indexing/bulk_test.exs

@@ -87,4 +87,11 @@ defmodule Elasticsearch.Index.BulkTest do
                "\"_routing\":\"123\""
     end
   end
+
+  describe ".encode!/4" do
+    test "'delete' omits the struct from the body" do
+      assert "{\"delete\":{\"_routing\":\"123\",\"_index\":\"my-index\",\"_id\":\"my-id\"}}\n" ==
+               Bulk.encode!(Cluster, %Comment{id: "my-id", post_id: "123"}, "my-index", "delete")
+    end
+  end
 end