Creating nested function score query from json via supplied reader

[Jangis93]

Java API client version

8.16.1

Java version

OpenJDK Runtime Environment Temurin-21.0.2+13

Elasticsearch Version

8.14.3

Problem description

Hello,

It seems like the fromJson method on the FuncitonScoreQuery object works differently with the latest client.

In our test setup we are using a function like this to create a query fixture from a supplied json which worked fine before the upgrade of the Java client, from 8.14.1 -> 8.16.1.

public static FunctionScoreQuery functionScoreQueryFromFile(String fileContent) {
		return FunctionScoreQuery.of(q1 -> q1.withJson(new StringReader(fileContent))));
}

The use case that we are having problems with is when we have a nested function score query like this:

{
  "functions": [
    {
      "field_value_factor": {
       ... 
      }
    }
  ],
  "query": {
    "function_score": {
      "query": {
        ...
      }
    }
  }
}

And we get the following error:

co.elastic.clients.json.JsonpMappingException: Error deserializing co.elastic.clients.elasticsearch._types.query_dsl.FunctionScore: Unknown field 'query' (JSON path: query.function_score.query)

Is this use case not valid anymore?

[l-trotta]

Hello, thanks for reporting this!

This is probably a side effect of this PR that we didn't notice at the time. We wanted to add support for the deserialization of the shortcut version of FunctionScoreQuery, and it seems like we accidentally broke it for this case.

I suggest using the java DSL to perform the call while we work on solving the issue, let me know if you need any help with translating - and sorry for the inconvenience!

[l-trotta]

just fixed this, will be out in the next 8.16.x and 8.17.x release! it was indeed a regression caused by us trying to support the shortcut version of FunctionScore, which unfortunately is something we cannot do without breaking deserialization for the standard case; so we reverted the changes.