KeyNumber.String() broke for go 1.14

[rbUUbr]

Please use the following questions as a guideline to help me answer
your issue/question without further inquiry. Thank you.

Which version of Elastic are you using?

[x] elastic.v7 (for Elasticsearch 7.x)
[ ] elastic.v6 (for Elasticsearch 6.x)
[ ] elastic.v5 (for Elasticsearch 5.x)
[ ] elastic.v3 (for Elasticsearch 2.x)
[ ] elastic.v2 (for Elasticsearch 1.x)

Hi! Great library! I'm using nested aggregation together with terms aggregation. I've just upgraded go to 1.14 and find out that AggregationBucketKeyItem returns empty string for aggregated keys in KeyNumber field

Please describe the expected behavior

Get same data in KeyNumber field that I have in Key field

Please describe the actual behavior

I'm getting "" in KeyNumber field, but I have actual data in Key field

Any steps to reproduce the behavior?

aggregation function

	myAggregation := elastic.NewNestedAggregation().Path("tags").SubAggregation(
		"tags",
		elastic.NewTermsAggregation().Field("tags.name").Size(20))
	service := elastic.Client.
		Search().
		Index("tags").
		Aggregation("tags", myAggregation).
		Query(elastic.NewBoolQuery())

transformation function:

	aggregation, found := searchResult.Aggregations.Nested("tags")
	if found {
		tagsResult, found := aggregation.Terms("tags")
		if found {
			bucketsCount := len(tagsResult.Buckets)
			result := make([]*models.TagCompanyGroup, bucketsCount)
			for i, b := range tagsResult.Buckets {
				//key := b.Key.(string)
				result[i] = &models.MyCustomTag{
					Tag: &models.Tag{
						Slug: b.KeyNumber.String(), // doesn't work with go 1.14
					},
					Key:            b.KeyNumber.String(), // doesn't work with go 1.14
					Count: b.DocCount,
				}
			}
			return result, nil
		}
	}

[olivere]

Thanks for letting me know. It seems weird that Go would change the behaviour of its encoding/json package. Can you post the HTTP response from ES as well? I need to come up with a reproducible test case so that we can illustrate the problem, fix it, and keep it fixed in future versions.

[olivere]

It seems to be somehow related to the change mentioned here in the Go 1.14 release notes. The issue is golang/go#37515, thoroughly discussed in golang/go#37308 (golang/go#14702).

It seems to me that the response doesn't return a valid number, in Go's sense. So waiting for sample output to create a reproducible test case.

[rbUUbr]

Hey there! sorry for long response time :(
here is the example:
request

# nested aggregation
POST my-index/_search/
{
  "size": 0, 
  "aggs": {
    "tags": {
      "nested": {
        "path": "tags"
      },
      "aggs": {
        "tags": {
          "terms": {
            "field": "tags.name.keyword",
            "size": 10
          }
        }
      }
    }
  }
}

response

{
  "took" : 38,
  "timed_out" : false,
  "_shards" : {
    "total" : 3,
    "successful" : 3,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 10000,
      "relation" : "gte"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "aggregations" : {
    "tags" : {
      "doc_count" : 419652,
      "tags" : {
        "doc_count_error_upper_bound" : 3115,
        "sum_other_doc_count" : 281277,
        "buckets" : [
          {
            "key" : "tag1",
            "doc_count" : 33333
          },
          {
            "key" : "tag2",
            "doc_count" : 4444
          },
          {
            "key" : "tag3",
            "doc_count" : 1000
          },
          {
            "key" : "tag4",
            "doc_count" : 950
          },
          {
            "key" : "tag5",
            "doc_count" : 900
          },
          {
            "key" : "tag6",
            "doc_count" : 800
          },
          {
            "key" : "tag7",
            "doc_count" : 700
          },
          {
            "key" : "tag8",
            "doc_count" : 600 
          },
          {
            "key" : "tag9",
            "doc_count" :500
          },
          {
            "key" : "tag10",
            "doc_count" : 400
          }
        ]
      }
    }
  }
}

[olivere]

I still cannot reproduce. I've written a test that checks various things about this issue, but I cannot get it to fail.

Please review https://github.com/olivere/elastic/blob/3db0060fd8cb964465de85d8062407472d6b8f46/search_aggs_bucket_terms_integration_test.go and change it so that it illustrates your point.

Will reopen then.