It should be possible to merge only if an explicit approval is given

[dnesting]

On GitLab enterprise, mp merge currently merges if it is possible to merge. If a repo is not configured with any merge rules requiring an approval, this means merges will occur potentially with no review. I would like the option to merge only if an explicit approval was given by a reviewer regardless of how the project is configured.

In addition, mp status should independently report the approval status of a pending MR.

[dnesting]

It looks like this should be possible using the GitLab Approvals API. Maybe:

GET /projects/:id/merge_requests/:merge_request_iid/approvals

{
  "id": 5,
  "iid": 5,
  "project_id": 1,
  "title": "Approvals API",
  "description": "Test",
  "state": "opened",
  "created_at": "2016-06-08T00:19:52.638Z",
  "updated_at": "2016-06-08T21:20:42.470Z",
  "merge_status": "cannot_be_merged",
  "approvals_required": 2,
  "approvals_left": 1,
  "approved_by": [
    {
      "user": {
        "name": "Administrator",
        "username": "root",
        "id": 1,
        "state": "active",
        "avatar_url": "http://www.gravatar.com/avatar/e64c7d89f26bd1972efa854d13d7dd61?s=80\u0026d=identicon",
        "web_url": "http://localhost:3000/root"
      }
    }
  ]
}

If approvals_left > 0 that implies the MR is missing approvals and we can signal that in mp status output. If approvals_left == 0 but len(approved_by) > 0 that implies an explicit approval was given and we can merge even when --require-approval. GitLab projects may have complex approval rules, though, and I don't know how best to handle that.