WIP: Recurring task with subtasks

[bartj3]

Hi,
I'd like to use this plugin but for my use case I need to recur the tasks subtasks as well, is this a functionality you'd consider to merge into the plugin if I would create a PR for this?

I'd imagine this to be a preference when creating a new recurrence (like the current Fixed schedule?). When true subtasks will be recreated in the same schedule as it's parent.

[nutso]

Hi,
Sure, always happy to have good contributions. Having the preference settable for each recurring task sounds like it won't impact current expected behavior while also providing a new capability.

[bartj3]

I've just attached my progress to this issue, there's still some work to do on the start_date & due_date of the subtasks as it now just assumes they'll be the same as the main issue but that doesn't have to be the case.

There's another issue i'd like to have your opinion on though:

For copying an issue issue.copy is used, by default this does copy the subtasks. However because the plugin never updated the values in the new subtasks they stayed closed. By changing update.copy to issue.copy nil, subtasks: recur_descendants? subtasks are only copied if the user wants to recur them, which seems to me like the proper way to go. However this is not backwards compatible. If users for some reason depended on the copied closed subtasks that will no longer work.

Do you think nobody is currently using the closed copied subtasks, and would this be an ok change for a minor release? Or should I just stick with the old issue.copy for now and add the subtasks option in the next major release of the plugin?

[bartj3]

Because of how Redmine couples the subtask dates with the parent dates this was a bit trickier then expected. It seems to be fixed now but I still need to write some extra tests to make sure it works in all of the edge cases. I didn't include the tests here because it might be better to create a new PR for that where more is tested then just the subtask recurrence.