Fixes a bug in interval filter serialization

[romseygeek]

@mattweber found an error in interval script filter serialization as part of #49519,
which I'm pulling out and fixing separately here.

[elasticmachine]

Pinging @elastic/es-search (:Search/Search)

[mattweber]

@romseygeek you will also want to fix equals and hashCode as they are missing script checks as well.

[romseygeek]

Good catch, thanks @mattweber !

[cbuescher]

@romseygeek the fix LGTM, but we have a bit of a hole in our testing here that I pointed out in a comment. Would you mind opening a follow up issue that we need to maybe need some unit test for the various IntervalsSourceProviders directly?

[cbuescher]

Adding these two variations is great to catch the xContent NPE but unfortunately doesn't directly trigger the Equals/Hashcode tests for the query builder due to a lack of coverage we have here (see https://github.com/elastic/elasticsearch/blob/master/test/framework/src/main/java/org/elasticsearch/test/AbstractQueryTestCase.java#L578). Without the equals/hashCode fixes this will trigger some of the "cachability" tests in this class, but very rarely.
I think adding these tests is out of scope for this PR but we should open an issue to maybe test wire- and xContent serialization of all the IntervalsSourceProvider implementations directly in unit tests. There seem to be none at the moment.

[romseygeek]

Thanks @cbuescher , I opened #49820 as a followup

[prasad2kin]

@mattweber @romseygeek, thanks for reporting and fixing this. I too was struggling with this problem for a week and trying to search the documentation/source code if I'm making any mistake.

Finally, I've reported this yesterday found myself convinced that it is an issue in the elastic code.: #50036

Just a quick question. Is it possible to backport this to 7.3.x branch?

[gpcmol]

@romseygeek @cbuescher Any ideas if this can be backported to 7.3.x fix branch?

[cbuescher]

7.3.x fix branch

@gpcmol we don't do patch releases on older minor versions, and since 7.5.1 is already out, thats the version we are currently releasing patches for.
This change however is currently only merged to the 7.6 branch.

[prasad2kin]

Hi @romseygeek, thanks for fixing this bug.

Just a question, how do I use this filter if I have to query for noWithin? Say, e.g. If I want to find the documents containing the term cake but not within the distance of 3 of the term tea?

Something like: description:(cake NOTNEAR3 tea) using the Intervals query or filter?

[romseygeek]

Hi @prasad2kin, you should be able to use something like:

"match" : { 
  "query" : "cake", 
  "filter" : { 
    "not_overlapping" : {
      "match" : {
        "query" : "cake tea",
        "max_gaps" : 3
      }
    }
  }
}

[prasad2kin]

Thanks for this Alan ( @romseygeek ). I'll try it. The above was a simple example, but I've use cases where I have a mix of wildcards + terms or fuzzy snippets.

Essentially, I was after getting an equivalent of span_not query. In fact, I've raised a feature request for the same: #64329