Convert ProtoBuf.js enum values to strings using reflection

protobufjs-stringify-enums.js

var _ = require('lodash');

function stringifyEnums(message) {
    _.forEach(message.$type.children, function(child) {
        var type = _.get(child, 'element.resolvedType', null);
        if (type && type.className === 'Enum' && type.children) {
            var metaValue = _.find(type.children, {
                id: message[child.name]
            });
            if (metaValue && metaValue.name)
                // Alternatively you can do something like:
                // message[child.name + '_string'] = metaValue.name;
                // To get access to both the raw value and the string.
                message[child.name] = metaValue.name;
        }
    });
    return message;
}

// stringifyEnums only works for direct children of one message.
// This function handles enums in submessages as well.
function stringifyEnumsRecursive(message) {
    message = stringifyEnums(message);
    _.forEach(message, function(subMessage, key) {
        if (_.isObject(subMessage) && subMessage.$type)
            message[key] = stringifyEnumsRecursive(message[key]);
    });
    return message;
}

module.exports = {
    stringifyEnums: stringifyEnums,
    stringifyEnumsRecursive: stringifyEnumsRecursive
};

or better go this way without lodash

utils.coffee

module.exports =
    stringifyEnums: (message) ->
        utils = @
        if (message and message.$type and message.$type.children)
            message.$type.children.forEach((child) ->
                if (message[child.name] and child.element.resolvedType)
                    switch child.element.resolvedType.className
                        when 'Enum'
                            dict = child.element.resolvedType.children.reduce(((acc, {id: id, name: name}) -> acc[id] = name ; acc), {})
                            if child.repeated
                                message[child.name] = message[child.name].map((el) -> dict[el])
                            else
                                message[child.name] = dict[message[child.name]]
                        when 'Message'
                            if child.repeated
                                message[child.name] = message[child.name].map((el) -> utils.stringifyEnums(el))
                            else
                                message[child.name] = utils.stringifyEnums(message[child.name]))
        message