#11 - create+switch default branch on release

[Ocramius]

Fixes #11 by providing default logic for switching to a new default branch at
every release. Specifically:

• when a newer release target branch exists, use that (i.e. release 1.2.3 => existing branch 1.5.x,
  switch to 1.5.x)
• when a newer release branch does not exist, create it (i.e. release 1.2.3 => existing branch 1.2.x,
  create 1.3.x from 1.2.x, use 1.3.x)
• when no release branches exist, skip entire execution

TODOs:

• try this out in a sandbox repository
• better documentation? (new feature/ files)
• update examples
• get rid of special handling for master, which is not interesting to us anymore
• document token requirements

Note: it would be good to get this into 1.0.0, since it breaks BC by changing semantics around the master branch naming.

[Ocramius]

Trying this out in the real world, it seems that my github actions GITHUB_TOKEN doesn't suffice for this sort of interaction, since that token cannot be used to PATCH /repos/:org/:name

Also tried to use a custom token, but no luck: pinging github support.

[Ocramius]

Yep, seems like GITHUB_TOKEN is scoped too strictly for this: PATCH /repos/:org/:name is not possible with that, and instead a custom admin-alike token is needed.

Don't know yet what the precise scope for it is.

Using a custom token produced the expected results at https://github.com/Ocramius/just-trying-automated-releases/runs/888025697?check_suite_focus=true, in which, by releasing 1.1.0, branch 1.2.x was created, published, and the repository switched to it.

[Ocramius]

Confirmed with github support:

The GITHUB_TOKEN is limited these permissions in the repository containing the workflow:

https://docs.github.com/en/actions/configuring-and-managing-workflows/authenticating-with-the-github_token#permissions-for-the-github_token

The following page details which GitHub App permissions are required for each endpoint and shows that making changes to the repository's settings, including changing the default branch, requires write on administration:

https://docs.github.com/en/rest/reference/permissions-required-for-github-apps#permission-on-administration

If you create a personal access token, the token will need the repo permission and will need to belong to a user with admin permissions on the repository.

[weierophinney]

Mainly a few questions.