Question [v4] Access purchaseResultDetails on key redeeming error

[Catzilla]

Hi.

I'm migrating from v3 to v4, and trying to redeem Steam key.
 
I added err argument as described in release notes, and now have the following code:

client.redeemKey(key, (err, detail, packages) => {
    if (err) {
        console.log('Can not redeem: ' + SteamUser.EPurchaseResultDetail[detail]);
        return;
    }
    console.log('Redeemed!');
});

If key can not be redeemed, in v3 I get detailed reason, for example DoesNotOwnRequiredApp.
But in v4 detail argument seems to be undefined.
How can I access this info now, after migration to v4?

Thanks

[Dr. McKay]

Promise limitations prevent any arguments besides err from being sent to the callback if an error occurred. If you update to v4.4.3, you'll be able to access this data via the Error object instead, using err.purchaseResultDetails and err.packageList.

[Catzilla]

Works fine, thanks a lot!

[Revadike]

I did this for the callback to support the old structure:

(result, detail, packages) => {
                // conversation new to old structure
                if (result) {
                    detail = result.purchaseResultDetails;
                    packages = result.packageList;
                    result = result.eresult;
                } else {
                    result = 1;
                }