Make type wrapping optional for PUT Mapping API request

Put mapping now supports either of these formats:

POST foo/doc/_mapping
{
  "doc": {
    "_routing": {"required": true},
    "properties": {
      "body": {"type": "string"}
    }
  }
}

or

POST foo/doc/_mapping
{
  "_routing": {"required": true},
  "properties": {
    "body": {"type": "string"}
  }
}

Closes #4483

src/main/java/org/elasticsearch/index/mapper/DocumentMapperParser.java

@@ -275,27 +275,19 @@ public class DocumentMapperParser extends AbstractIndexComponent {
 
     @SuppressWarnings({"unchecked"})
     private Tuple<String, Map<String, Object>> extractMapping(String type, Map<String, Object> root) throws MapperParsingException {
-        int size = root.size();
+        if (root.size() == 0) {
-        switch (size) {
+            // if we don't have any keys throw an exception
-            case 0:
+            throw new MapperParsingException("malformed mapping no root object found");
-                // if we don't have any keys throw an exception
-                throw new MapperParsingException("malformed mapping no root object found");
-            case 1:
-                break;
-            default:
-                // we always assume the first and single key is the mapping type root
-                throw new MapperParsingException("mapping must have the `type` as the root object");
         }
 
         String rootName = root.keySet().iterator().next();
-        if (type == null) {
+        Tuple<String, Map<String, Object>> mapping;
-            type = rootName;
+        if (type == null || type.equals(rootName)) {
-        } else if (!type.equals(rootName)) {
+            mapping = new Tuple<String, Map<String, Object>>(rootName, (Map<String, Object>) root.get(rootName));
-            // we always assume the first and single key is the mapping type root
+        } else {
-            throw new MapperParsingException("mapping must have the `type` as the root object. Got [" + rootName + "], expected [" + type + "]");
+            mapping = new Tuple<String, Map<String, Object>>(type, root);
         }
 
-
+        return mapping;
-        return new Tuple<String, Map<String, Object>>(type, (Map<String, Object>) root.get(rootName));
     }
 }

src/test/java/org/elasticsearch/indices/mapping/UpdateMappingTests.java

@@ -120,6 +120,49 @@ public class UpdateMappingTests extends ElasticsearchIntegrationTest {
         }
     }
 
+    @Test
+    public void updateMappingWithoutType() throws Exception {
+        client().admin().indices().prepareCreate("test")
+                .setSettings(
+                        ImmutableSettings.settingsBuilder()
+                                .put("index.number_of_shards", 1)
+                                .put("index.number_of_replicas", 0)
+                ).addMapping("doc", "{\"doc\":{\"properties\":{\"body\":{\"type\":\"string\"}}}}")
+                .execute().actionGet();
+        client().admin().cluster().prepareHealth().setWaitForEvents(Priority.LANGUID).setWaitForGreenStatus().execute().actionGet();
+
+        PutMappingResponse putMappingResponse = client().admin().indices().preparePutMapping("test").setType("doc")
+                .setSource("{\"properties\":{\"date\":{\"type\":\"integer\"}}}")
+                .execute().actionGet();
+
+        assertThat(putMappingResponse.isAcknowledged(), equalTo(true));
+
+        GetMappingsResponse getMappingsResponse = client().admin().indices().prepareGetMappings("test").execute().actionGet();
+        assertThat(getMappingsResponse.mappings().get("test").get("doc").source().toString(),
+                equalTo("{\"doc\":{\"properties\":{\"body\":{\"type\":\"string\"},\"date\":{\"type\":\"integer\"}}}}"));
+    }
+
+    @Test
+    public void updateMappingWithoutTypeMultiObjects() throws Exception {
+        client().admin().indices().prepareCreate("test")
+                .setSettings(
+                        ImmutableSettings.settingsBuilder()
+                                .put("index.number_of_shards", 1)
+                                .put("index.number_of_replicas", 0)
+                ).execute().actionGet();
+        client().admin().cluster().prepareHealth().setWaitForEvents(Priority.LANGUID).setWaitForGreenStatus().execute().actionGet();
+
+        PutMappingResponse putMappingResponse = client().admin().indices().preparePutMapping("test").setType("doc")
+                .setSource("{\"_source\":{\"enabled\":false},\"properties\":{\"date\":{\"type\":\"integer\"}}}")
+                .execute().actionGet();
+
+        assertThat(putMappingResponse.isAcknowledged(), equalTo(true));
+
+        GetMappingsResponse getMappingsResponse = client().admin().indices().prepareGetMappings("test").execute().actionGet();
+        assertThat(getMappingsResponse.mappings().get("test").get("doc").source().toString(),
+                equalTo("{\"doc\":{\"_source\":{\"enabled\":false},\"properties\":{\"date\":{\"type\":\"integer\"}}}}"));
+    }
+
     @Test(expected = MergeMappingException.class)
     public void updateMappingWithConflicts() throws Exception {