private async Task <Result> UpdatePlanWithStripe(List <int> packageIds, string customerId, string subscriptionId)
{
return(await packages.FetchSubscriptionPackagesFromIds(packageIds)
.Ensure(p => p.HasValue, "Packages found")
.OnSuccess(p => p.Value.Select(pkg => pkg.ExternalPackageId).ToList())
.OnSuccess(p => billingManager.UpdateSubscription(customerId, subscriptionId, p))
.ConfigureAwait(false));
}
