Support for Custom or Generic Release Branch Naming Conventions

[DarudeGarystorm]

Currently, the repository enforces a specific branch naming convention for release branches in the format release/<major>.<minor>.<patch> . While this works well for many use cases, there are many companies migrating from bitbucket to github where this pattern won't apply.

Request

Enable more flexible or generic branch naming conventions. Specifically, the ability to add a prefix or suffix as shown in the bitbucket documentation https://confluence.atlassian.com/bitbucketserver/cascading-merge-776639993.html:

• release/bitbucket_1.1
• release/1.1_bitbucket

[DarudeGarystorm]

Hey @ncalteen, I found a bug here.

In the fourth bullet of the branch ordering algorithm it states that numbers are ranked higher than ASCII, but we have it backwards.

To fix this all we need to do is swap the -1 and 1.

Here is a test case that reproduces the issue:

test('handles custom formatted "major" release branches used in some organizations', async () => {
  const getBranchMergeOrder = automerge.__get__('getBranchMergeOrder')
  const response = await getBranchMergeOrder(
    'release/',
    'release/d-3-2024-01-07-avocado',
    [
      { name: 'release/d-3-2024-01-07-avocado' },
      { name: 'release/d-1-2022-09-22-mercury' },
      { name: 'release/d-5' },
      { name: 'release/d-3-2024-06-21-cucumber' },
      { name: 'release/d-4-codename' },
      { name: 'release/d-3-2024-06-03-carrot' },
      { name: 'release/d-4-2025-08-09-legal' }
    ]
  )
  expect.assertions(1)

  expect(response).toEqual([
    'release/d-3-2024-01-07-avocado',
    'release/d-3-2024-06-03-carrot',
    'release/d-3-2024-06-21-cucumber',
    'release/d-4-codename',
    'release/d-4-2025-08-09-legal',
    'release/d-5'
  ])
})