Support convenience decimal type syntax in IDL files

[crypticmind]

I have a schema like this:

protocol P {
  record R {
    decimal(10, 2) dec;
  }
}

However, protocol parsing chokes on the opening parenthesis with:

Error: invalid token {"pos":xx,"id":"operator","val":"("}: expected ID name

As I see it, avsc support logical types from JSON schema, but not from IDL. Is there any way to enable this, or does the IDL parser require updating?

[mtth]

Hi @crypticmind, avsc doesn't support decimal logical type sugar in IDL files yet. In the meantime, you can use annotations. It would look something like:

protocol P {
  record R {
    @logicalType("decimal") @precision(10) @scale(2) bytes dec;
  }
}

If you use the type in many places, you can also add it via typeRefs:

const opts = {
  typeRefs: {my_decimal: {type: 'bytes', logicalType: 'decimal', precision: 10, scale: 2}}
};
avro.assembleProtocol(str, opts, (err, schema) => { /* ... */ });

Simplifying your protocol to:

protocol P {
  record R {
    my_decimal dec;
  }
}

[crypticmind]

@mtth thank you for the quick response.

[JohannesKlauss]

@mtth I have the same issue, but I am only reading the schema, I can't change it.
The result is that I get a decoded object looking like this:

price: Price {
    net: <Buffer 01 48 20>,
    gross: <Buffer 01 86 a0>,
    currency: 'EUR'
}

The schema looks like this:

record Price {
    decimal(10,4) net;
    decimal(10,4) gross;
    string currency;
}

Can I somehow tell the resolver how to decode those values?