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.

3 files changed, 16 insertions, 13 deletions

diff --git a/spec/factories/protected_branches.rb b/spec/factories/protected_branches.rb
index 5575852c2d7..3b21174987f 100644
--- a/spec/factories/protected_branches.rb
+++ b/spec/factories/protected_branches.rb
@@ -4,25 +4,25 @@ FactoryGirl.define do
     project
 
     after(:create) do |protected_branch|
-      protected_branch.create_push_access_level!(access_level: Gitlab::Access::MASTER)
-      protected_branch.create_merge_access_level!(access_level: Gitlab::Access::MASTER)
+      protected_branch.push_access_levels.create!(access_level: Gitlab::Access::MASTER)
+      protected_branch.merge_access_levels.create!(access_level: Gitlab::Access::MASTER)
     end
 
     trait :developers_can_push do
       after(:create) do |protected_branch|
-        protected_branch.push_access_level.update!(access_level: Gitlab::Access::DEVELOPER)
+        protected_branch.push_access_levels.first.update!(access_level: Gitlab::Access::DEVELOPER)
       end
     end
 
     trait :developers_can_merge do
       after(:create) do |protected_branch|
-        protected_branch.merge_access_level.update!(access_level: Gitlab::Access::DEVELOPER)
+        protected_branch.merge_access_levels.first.update!(access_level: Gitlab::Access::DEVELOPER)
       end
     end
 
     trait :no_one_can_push do
       after(:create) do |protected_branch|
-        protected_branch.push_access_level.update!(access_level: Gitlab::Access::NO_ACCESS)
+        protected_branch.push_access_levels.first.update!(access_level: Gitlab::Access::NO_ACCESS)
       end
     end
   end
diff --git a/spec/features/protected_branches_spec.rb b/spec/features/protected_branches_spec.rb
index 3499460c84d..5beb658b2f5 100644
--- a/spec/features/protected_branches_spec.rb
+++ b/spec/features/protected_branches_spec.rb
@@ -71,7 +71,10 @@ feature 'Projected Branches', feature: true, js: true do
       project.repository.add_branch(user, 'production-stable', 'master')
       project.repository.add_branch(user, 'staging-stable', 'master')
       project.repository.add_branch(user, 'development', 'master')
-      create(:protected_branch, project: project, name: "*-stable")
+
+      visit namespace_project_protected_branches_path(project.namespace, project)
+      set_protected_branch_name('*-stable')
+      click_on "Protect"
 
       visit namespace_project_protected_branches_path(project.namespace, project)
       click_on "2 matching branches"
@@ -96,7 +99,7 @@ feature 'Projected Branches', feature: true, js: true do
         click_on "Protect"
 
         expect(ProtectedBranch.count).to eq(1)
-        expect(ProtectedBranch.last.push_access_level.access_level).to eq(access_type_id)
+        expect(ProtectedBranch.last.push_access_levels.first.access_level).to eq(access_type_id)
       end
 
       it "allows updating protected branches so that #{access_type_name} can push to them" do
@@ -112,7 +115,7 @@ feature 'Projected Branches', feature: true, js: true do
         end
 
         wait_for_ajax
-        expect(ProtectedBranch.last.push_access_level.access_level).to eq(access_type_id)
+        expect(ProtectedBranch.last.push_access_levels.first.access_level).to eq(access_type_id)
       end
     end
 
@@ -127,7 +130,7 @@ feature 'Projected Branches', feature: true, js: true do
         click_on "Protect"
 
         expect(ProtectedBranch.count).to eq(1)
-        expect(ProtectedBranch.last.merge_access_level.access_level).to eq(access_type_id)
+        expect(ProtectedBranch.last.merge_access_levels.first.access_level).to eq(access_type_id)
       end
 
       it "allows updating protected branches so that #{access_type_name} can merge to them" do
@@ -143,7 +146,7 @@ feature 'Projected Branches', feature: true, js: true do
         end
 
         wait_for_ajax
-        expect(ProtectedBranch.last.merge_access_level.access_level).to eq(access_type_id)
+        expect(ProtectedBranch.last.merge_access_levels.first.access_level).to eq(access_type_id)
       end
     end
   end
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