Nest search query returning different results from the Elastic query DSL

Question

I have an ElasticSearch index called challenges , which contains objects of type Challenge .

When I execute the following filter query in the Kibana console, it returns the 9 results, which are correct.

GET challenges/_search
{
  "query": {
    "bool": {
      "filter": [
        {
          "term": {
            "type": "Orphan"
          }
        }
      ]
    }
  }
}

However, the following query from the Nest client, returns zero hits:

var challenges = await _client.SearchAsync<Challenge>(s => s
  .Query(q => +q
    .Term(t => t.Type, Models.Enums.ChallengeType.Orphan)
  )
);

I've also tried the following variation, to no avail:

var challenges = await _client.SearchAsync<Challenge>(s => s
  .Query(q => q
    .Bool(b => b
      .Filter(f => f
        .Term(t => t
          .Field(f => f.Type)
          .Value(challengeType)
        )
      )
    )
  )
);

The type property on which I'm filtering, is an enum with the following values:

public enum ChallengeType
{
  SixDimensions,
  Intro,
  Normal,
  UserCreated,
  Orphan,
  Youmate
}

and is stored as a keyword in the index. An example object that is actually in the index:

{
  "id": "3bce0ce1-9676-4858-b165-1442a443bf5a",
  "icon": "water-bottle.png",
  "index": 0,
  "default-time": "09:00",
  "default-days": [
    "Saturday",
    "Monday",
    "Wednesday"
  ],
  "default-repetitions": 3,
  "category": "A",
  "title": {
    "Persian": "آب خوردن"
  },
  "dimension": "Physical",
  "type": "Orphan",
  "id-package": "00000000-0000-0000-0000-000000000000",
  "intro-pages": [ ],
  "date-created": "2020-10-14T12:39:21.8427517+03:30",
  "notify": true,
  "template": 0,
  "belongs-to-user": "00000000-0000-0000-0000-000000000000",
  "active": false
}

Do you have any suggestions as to why the results from the console differ from when it is executed from the Nest client?

Answer 1

The enum should be marked with StringEnumAttribute to serialize as a string

[StringEnum]
public enum ChallengeType
{
    SixDimensions,
    Intro,
    Normal,
    UserCreated,
    Orphan,
    Youmate
}

Without this, the enum will be serialized as its underlying integer value.