Cannot set default value for timestamp logical types

[jameshartig]

The MarshalJSON method for the time.Time struct:

// MarshalJSON implements the json.Marshaler interface.
// The time is a quoted string in RFC 3339 format, with sub-second precision added if present.

Which means if you're generating an avro file and specify a default of time.Time{} it will marshal that as a string and then you get:

cannot create OCFWriter: cannot create OCF header: Record "analytics.submission" field "ts": default value ought to encode using field schema: cannot transform binary timestamp-micros, expected time.Time, received string

Since NewCodec unmarshalling the schema into an interface{} there's no way for the json package to know that it should be a time.Time to unmarshal into and not a plain string. I think timeStampMillisFromNative (and other timestamp types) should check to see if the value is a string and then unmarshal into a time.Time and that should fix the issue.

@kdvy, what do you think?

[kdvy]

Apologies for the oversight! We didn't have a requirement for default values and it slipped my mind.

I certainly have no objections to your suggestion and it sounds like the correct approach to me. I'm afraid I don't to have time to add this functionality at the moment due to impending holiday + deadlines.

Thanks for pointing this out and feel free to ping me if you need anything.

[kdvy]

Have created a PR, but a schema that uses defaults with RFC3339 may not be cross-library compatible since the base type is long.

[karrick]

Resolved by #136

[kdarkhan]

@karrick this issue is not resolved because the linked PR was rejected.
Can we reopen this?