Deprecated field [include] used, expected [includes] instead

[adiloztaser]

Describe the bug
When I was working on the user integration feature in our project, I realized that Elasticsearch returns this warning. I am not quite sure but include deprecated in Elasticsearch 6.6.0 (Deprecate _source_include and _source_exclude url parameters #33475).

I think the warning will be solved when if we replace include with includes.

Here is my simple user query:

$users = new WP_User_Query( array(
	'search'        => $name,
	'search_fields' => array( 'display_name' ),
	'fields'        => array( 'ID', 'display_name' ),
	'number'        => $number,
	'offset'        => $offset,
	'ep_integrate'  => true
) );

Elasticsearch query which returns warning

{
  "from": 0,
  "size": 20,
  "_source": {
    "include": [
      "ID",
      "display_name"
    ]
  },
  "query": {
    "bool": {
      "should": [
        {
          "multi_match": {
            "query": "Nefis Yemek Tarifleri",
            "type": "phrase",
            "fields": [
              "display_name"
            ],
            "boost": 4
          }
        },
        {
          "multi_match": {
            "query": "Nefis Yemek Tarifleri",
            "fields": [
              "display_name"
            ],
            "boost": 2,
            "fuzziness": 0,
            "operator": "and"
          }
        },
        {
          "multi_match": {
            "fields": [
              "display_name"
            ],
            "query": "Nefis Yemek Tarifleri",
            "fuzziness": 1
          }
        }
      ]
    }
  },
  "sort": [
    {
      "user_login.raw": {
        "order": "asc"
      }
    }
  ]
}

Here is the whole warning line:
[2020-05-12T09:54:33,143][WARN ][o.e.d.c.ParseField ] Deprecated field [include] used, expected [includes] instead

Environment information

• WordPress version: 5.3.3
• ElasticPress version: 3.4.1
• Elasticsearch version: 6.3.2

[dinhtungdu]

@adiloztaser I addressed this issue in #1788. If you have time, can you please test and review it?

[adiloztaser]

Hi @dinhtungdu,

The pr fixes my problem, but I did not test any other Elasticsearch versions which are older than 6.3.2. Do you know the older Elasticsearch versions support the includes field? If they do not support there may be a problem.

[dinhtungdu]

@adiloztaser I tested with ES 5.6.16 and it works without any warning. The docs for ES 5.0 and above shows includes example too.

[adiloztaser]

@dinhtungdu thanks for the information and your work 👍