Debt: Consolidate mod processing in addRecordSRV/addRecord

[tlimoncelli]

There is a lot of repeated code in addRecordSRV/addRecord. It should be collapsed into a helper function.

[whs]

I could take on this.

I'm thinking of something like:

var CNAME = recordBuilder({
    type: 'CNAME',
});

which should take care of the (name, target) type.

For special cases like SRV a hook could be added

var SRV = recordBuilder({
    type: 'SRV',
    args: [
        ['name', _.isString], // second argument can be omitted/null if validation is not needed
        ['priority', _.isNumber],
        ['weight', _.isNumber],
        ['port', _.isNumber],
        ['target', _.isString],
    ],
    transform: function(record, args, modifiers){
        // record is {type: 'SRV', ttl:d.defaultTTL, meta:{}}
        // with modifiers already applied
        // args will be an object for parameters defined

        record.name = args.name;
        record.srvpriority = args.priority;
        record.srvweight = args.srvweight;
        record.srvport = args.srvport;
        record.target = args.target;

        return record;
    },
    // example of number modifier parsing (eg. in CAA)
    modifierNumber: function(record, value){
        record.caaflags |= value;
        return record;
    }
});

Record could implement modifierNumber and modifierString modifierBoolean (basically all primitive types but null/undefined) to support custom record modifier like what MX/CAA are using now. The default handler for those options will log "Warning: Number/String/Boolean modifier (value) is not supported. Skipping"

Is there any use case that I missed?

[captncraig]

I was thinking even simpler. Have addRecord return an object, and SRV just adds some fields to it after it finishes. So addRecord does the common things, runs modifiers, etc. and SRV adds its own fields after. Sometimes the over functional style is good, but others it makes things odd.

[whs]

That still retain the special cases of number modifier parsing for CAA/MX. As addRecord will warn on unknown modifier, handling the number modifiers in the CAA function will also trigger the warning.

[tlimoncelli]

Fixed in #157 and #163