Support Branch renaming

[aj-codecov]

From Terry: https://codecovio.atlassian.net/browse/CODE-3581

Customer driven feature request

We are not listening for new branch names and updating our DB to show the correct information. After talking with Scott + Joe we do not seem to have an existing webhook to listen for this event. How will this impact the timeseries DB?

Current Behavior:
When renaming a branch Codecov looses the history of the branch and only displays data post rename. The old branch name appears as another branch (instead of being renamed) so it’s data lingers in branch lists.

Expected behavior:

Using a webhook to listen for the equivalent of a rename event and update our database with the new branch name so historical data is not lost/duplicated. Batching this update might be good as some branches could have years of commit history.

AJ Notes from chat with Joe:
When a branch is renamed:

GH repo hook PUSH that gives us an object_ref change - it says X commit is now on Y branch

GH repo hook PUSH on old branch moving ref for old branch name from what it was to nothing at all

GH repo create event for new branch

GH delete on old branch name

https://github.com/codecov/codecov-api/blob/master/webhook_handlers/views/github.py#L204

In this^ WH we need: IF branch AND IF branch name deleted=TRUE OR branch name created=TRUE THEN move all the things from old_branch to new_branch

Tasks

Preview Give feedback

1. Support Branch Renaming engineering-team#135
   0 of 1
   P2: stretch +1