Backport changes from gitlab-org/gitlab-ee!581 to CE.

!581 has a lot of changes that would cause merge conflicts if not
properly backported to CE. This commit/MR serves as a better
foundation for gitlab-org/gitlab-ee!581.

= Changes =

1. Move from `has_one {merge,push}_access_level` to `has_many`, with the
   `length` of the association limited to `1`. This is _effectively_ a
   `has_one` association, but should cause less conflicts with EE, which
   is set to `has_many`. This has a number of related changes in the
   views, specs, and factories.

2. Make `gon` variable loading more consistent (with EE!581) in the
   `ProtectedBranchesController`. Also use `::` to prefix the
   `ProtectedBranches` services, because this is required in EE.

3. Extract a `ProtectedBranchAccess` concern from the two access level
   models. This concern only has a single `humanize` method here, but
   will have more methods in EE.

4. Add `form_errors` to the protected branches creation form. This is
   not strictly required for EE compatibility, but was an oversight
   nonetheless.

1 files changed, 3 insertions, 3 deletions

diff --git a/spec/services/git_push_service_spec.rb b/spec/services/git_push_service_spec.rb
index 80f6ebac86c..850b45f84f9 100644
--- a/spec/services/git_push_service_spec.rb
+++ b/spec/services/git_push_service_spec.rb
@@ -228,7 +228,7 @@ describe GitPushService, services: true do
         execute_service(project, user, @blankrev, 'newrev', 'refs/heads/master' )
         expect(project.protected_branches).not_to be_empty
         expect(project.protected_branches.first.push_access_level.access_level).to eq(Gitlab::Access::MASTER)
-        expect(project.protected_branches.first.merge_access_level.access_level).to eq(Gitlab::Access::MASTER)
+        expect(project.protected_branches.first.merge_access_levels.first.access_level).to eq(Gitlab::Access::MASTER)
       end
 
       it "when pushing a branch for the first time with default branch protection disabled" do
@@ -250,7 +250,7 @@ describe GitPushService, services: true do
 
         expect(project.protected_branches).not_to be_empty
         expect(project.protected_branches.last.push_access_level.access_level).to eq(Gitlab::Access::DEVELOPER)
-        expect(project.protected_branches.last.merge_access_level.access_level).to eq(Gitlab::Access::MASTER)
+        expect(project.protected_branches.last.merge_access_levels.first.access_level).to eq(Gitlab::Access::MASTER)
       end
 
       it "when pushing a branch for the first time with default branch protection set to 'developers can merge'" do
@@ -261,7 +261,7 @@ describe GitPushService, services: true do
         execute_service(project, user, @blankrev, 'newrev', 'refs/heads/master' )
         expect(project.protected_branches).not_to be_empty
         expect(project.protected_branches.first.push_access_level.access_level).to eq(Gitlab::Access::MASTER)
-        expect(project.protected_branches.first.merge_access_level.access_level).to eq(Gitlab::Access::DEVELOPER)
+        expect(project.protected_branches.first.merge_access_levels.first.access_level).to eq(Gitlab::Access::DEVELOPER)
       end
 
       it "when pushing new commits to existing branch" do