private async Task <ImmutableList <string> > GetUpstreamBranches(string branch, Dictionary <string, ImmutableList <string> > upstreamBranchListings)
{
if (!upstreamBranchListings.ContainsKey(branch))
{
var result = (
from b in (await settings.GetUpstreamBranches(branch).FirstOrDefaultAsync())
select b.GroupName
).ToImmutableList();
var removed = new HashSet <string>();
foreach (var entry in result.ToArray())
{
if (removed.Contains(entry))
{
// already found this as an exception
continue;
}
foreach (var newEntry in (await settings.GetAllUpstreamBranches(entry).FirstOrDefaultAsync()).Select(b => b.GroupName))
{
removed.Add(newEntry);
}
}
upstreamBranchListings[branch] = result.Except(removed).ToImmutableList();
}
return(upstreamBranchListings[branch]);
}
public async Task <string[]> UpstreamBranches(string branchName)
{
return(await branchSettings.GetUpstreamBranches(branchName).FirstAsync());
}