type clone() with wrapUnions does not work?

[aidanbon]

Following the discussion at #16 and cut and paste the sample code mentioned in the stackoverflow (see below), I expect the cloned value is in wrapped format, but turns out it is still unwrapped?! Do I miss something?

Here's the cut-n-paste from the stackoverflow discussion:
http://stackoverflow.com/questions/33236284/how-to-convert-a-json-object-into-avro-object-if-avro-schema-contains-union-in-i/33622239#33622239

var avsc = require('avsc');

var type =  avsc.parse({
  "type":"record",
  "name":"DataFlowEntity",
  "namespace":"org.sdf.manage.commons.server",
  "fields": [
    {"name":"dataTypeGroupName","type":["null","string"]},
    {"name":"dataTypeName","type":"string"},
    {"name":"dataSchemaVersion","type":"string"}
  ]
});

var invalidRecord = {
  "dataTypeGroupName": "dg_1",
  "dataTypeName": "dt_1",
  "dataSchemaVersion": "1"
};

var validRecord = type.clone(invalidRecord, {wrapUnions: true});
console.log(validRecord)

Expected cloned value as wrapped:

{
  "dataTypeGroupName":{"string":"dg_1"},
  "dataTypeName":"dt_1",
  "dataSchemaVersion":"1"
}

But the above code returns unwrapped result?!

{
  "dataTypeGroupName":"dg_1",
  "dataTypeName":"dt_1",
  "dataSchemaVersion":"1"
}

[mtth]

It's because 5.0 changed the default wrapping behavior when parsing types: unions are now only represented wrapped where needed.

clone's wrapUnions option only takes effect when the underlying union is wrapped which isn't the case above since ["null", "string"] isn't ambiguous (take a look at the union types for a bit more information).

You can still force wrapping by explicitly setting parse's wrapUnions option though; here's a type that'll make your example work as expected:

var type =  avsc.parse({
  "type":"record",
  "name":"DataFlowEntity",
  "namespace":"org.sdf.manage.commons.server",
  "fields": [
    {"name":"dataTypeGroupName","type":["null","string"]},
    {"name":"dataTypeName","type":"string"},
    {"name":"dataSchemaVersion","type":"string"}
  ]
}, {wrapUnions: true});

I updated the example on Stack Overflow to reflect the change. Thanks for bringing it up!