.github/mergeable.yml

version: 2
mergeable:
  - when: pull_request.*
    validate:
      - do: label
        must_include:
          regex: '^Type:'
    fail:
      - do: checks
        status: 'failure'
        payload:
          title: 'Need an appropriate "Type:" label'
          summary: 'Need an appropriate "Type:" label'
  - when: pull_request.*
    # This validator requires either the "no release notes" label OR a "Release" milestone
    # to be considered successful.  However, validators "pass" in mergeable only if all
    # checks pass.  So it is implemented in reverse.
    # I.e.: !(!no_relnotes && !release_milestone) ==> no_relnotes || release_milestone
    # If both validators pass, then it is considered a failure, and if either fails, it is
    # considered a success.
    validate:
      - do: label
        must_exclude:
          regex: '^no release notes$'
      - do: milestone
        must_exclude:
          regex: 'Release$'
    pass:
      - do: checks
        status: 'failure'  # fail on pass
        payload:
          title: 'Need Release milestone or "no release notes" label'
          summary: 'Need Release milestone or "no release notes" label'
    fail:
      - do: checks
        status: 'success' # pass on fail