Discrepancy between Query types in Fields property about elasticsearch-net HOT 1 CLOSED

Hi @gpetrou,

thanks again for testing the new version and reporting rough edges. That's super helpful 🙂

Semantics for Fields and Field[] are actually different. The specification defines Fields as:

export type Fields = Field | Field[]

We call this a "single-or-many" construct. The ES server accepts the JSON property in a singular form "field" and in an array form ["field", "..."].

Field[] on the other hand, only accepts the array form.

The old generator incorrectly replaced Field[] with Fields which caused an issue with e.g. the stored_fields that Steve tried to fix in #8018.

The current way of generating these properties is semantically correct, but a litte bit cumbersome to use. A proper fix that I've planned involves removing the [JsonConverter(typeof(FieldsConverter))] attribute from the Fields class. Afterwards, the generator will emit Field[] properties using the Fields type again, but dynamically places converter attributes on the properties - depending on the semantics (either FieldsConverter or FieldArrayConverter).

I expect to release this improvement already in the beginning of the next week.

from elasticsearch-net.