invalid configuration causes app to explode

[mfkp]

Just ran into this in my production system.

If you pass in an empty hours hash in config.hours, or if a single day has an empty hash, and you do something like:

biz = Biz::Schedule.new do |config|
  config.hours = {}
end

biz.periods
  .after(local_date.beginning_of_day)
  .timeline
  .forward
  .until(local_date.end_of_day)
  .to_a

then it'll spin forever and blow up your server.

This happened to me because I have subtractive hours, so sometimes it turns out that there can be no hours for a certain timeframe.

[craiglittle]

Hey, @mfkp!

One solution for your particular use case is to return early if the configuration is empty, avoiding the calls to biz entirely.

From the prospective of biz, given that methods like Biz::time would provide nonsensical results when provided an empty configuration, I think the solution to this issue is to raise a configuration validation error upfront at configuration time.

Does that seem reasonable?

[mfkp]

Yeah, raising an error seems like a valid solution. Really, anything is better than melting the cpu 😄

Took me a while to track it down too, something loud like that would make it easier to find next time.