Deleting nested field object with hyphens via inline scripting

[kamharrah (Kamerynn Harrah)]

This is an issue I am running into with our v2.4 cluster (using groovy), but I can also reproduce the error in v5.6 (using painless).

When I delete fields inside of an object, I send a request to the Update API with an inline script to remove the inner field.

E.g. for an document in the format below:
{
person_details: {
first_name: "Kamerynn"
last_name: "Harrah"
}
}

The request to delete the last name field would look like:
POST hostname/index/person/1/_update
{
"script": "ctx._source.person_details.remove("first_name");"
}

However, there is an issue I am running into, specifically when the object fields have a hyphen in them.

E.g., if the object instead looked like this (notice the hyphen instead of the underscore)
{
person-details: {
first-name: "Kamerynn"
last-name: "Harrah"
}
}

The following script would throw an IllegalArgumentException:
{
"script": "ctx._source.person-details.remove("first-name");"
}

The problem is not from the hyphen in the field being removed. The problem is from "person-details" having a hyphen, which seems to cause issues with the groovy syntax.

I have googled approaches to this problem with no success. One suggestion on StackOverflow was to use a sequence of chained methods "{field}.[path.to](http://path.to/)[\"{inner_field}\"]" within groovy, but that does not seem to work, and I cannot find any documentation for those methods.

I am hopeful that, since Elasticsearch allows the use of hyphens in inner object field names, there is a syntax for removing these fields that I am unaware of!

Appreciate any help, thank you!

[kamharrah (Kamerynn Harrah)]

Elastic support helped with this issue. You are able to use square brackets to reference nested fields with special characters (like Javascript's syntax). So the following would work:

{
"script": "ctx._source["person-details"].remove("first-name");"
}