script_score query does not support [params] in ElasticSearch 5.0 about elasticsearchdsl

[saimaz]

Function score now has a different structure and don't use script_score if I don't miss anything.

https://www.elastic.co/guide/en/elasticsearch/reference/5.1/query-dsl-function-score-query.html#function-script-score

Removing params might not solve the issue.

[saimaz]

My bad, actually params seems are still there in 5.x: https://www.elastic.co/guide/en/elasticsearch/reference/5.1/query-dsl-function-score-query.html#function-script-score

[KnysakPatryk]

For now it's just throwing exception and kills the script (even if you don't use this feature). With this fix it's not throwing exception. But I know, for fixing this issue entirely, it's required to make futher changes.

[saimaz]

Let's take a look if there is possible to make some adjustments by keeping BC for 2.x Elasticsearch. If the params causes exception maybe it can be filtered out if this is an empty array?

[KnysakPatryk]

In my opinion we should BC. Even elasticsearch/elasticsearch recommends using v5 library with v5 ES. To be honest, this library is not working good with complicated queries accross different ES versions. If you don't believe me, just check it out by yourself.

[saimaz]

elasticsearch/elasticsearch v5 dropped 2.x support for a number of other reasons. Since this library just builds a query, it was ok.

This is the first example it causes search body differences. And if there is no solution, for sure I will release a new major version by dropping 2.x support as well.

[saimaz]

Related to #177

[saimaz]

Fixed in #186

[saimaz]

There is also a test PR (#189) which will check if function score is working correctly on 2.x and 5.x elasticsearch.