Encoding a struct with a sub-record field default value failed about avro HOT 2 CLOSED

Got inspired by encoderOfRecord implementation and made a fix PR #322

from avro.

My understanding of Avro is that fields of type Record support default values only if the sub-record is defined separately (not as a nested record).

This is not correct. The spec says the default value is only really used for reading in case of schema evolution:

default: A default value for this field, only used when reading instances that lack the field for schema evolution purposes. The presence of a default value does not make the field optional at encoding time. Permitted values depend on the field’s schema type, according to the table below.

It is has been specifically decided to go against this, as it has no lasting effect outside of the encoding itself, and so is a local convenience, where the field can potentially not exist.

This however does not change the panic you are seeing.

from avro.