Enabled no-one as a merge access level in protected branches

Closes #31541

app/models/concerns/protected_branch_access.rb

@@ -7,5 +7,23 @@ module ProtectedBranchAccess
     belongs_to :protected_branch
 
     delegate :project, to: :protected_branch
+
+    validates :access_level, presence: true, inclusion: { in: [Gitlab::Access::MASTER,
+                                                               Gitlab::Access::DEVELOPER,
+                                                               Gitlab::Access::NO_ACCESS] }
+
+    def self.human_access_levels
+      {
+        Gitlab::Access::MASTER => "Masters",
+        Gitlab::Access::DEVELOPER => "Developers + Masters",
+        Gitlab::Access::NO_ACCESS => "No one"
+      }.with_indifferent_access
+    end
+
+    def check_access(user)
+      return false if access_level == Gitlab::Access::NO_ACCESS
+
+      super
+    end
   end
 end

app/models/protected_branch/merge_access_level.rb

@@ -1,13 +1,3 @@
 class ProtectedBranch::MergeAccessLevel < ActiveRecord::Base
   include ProtectedBranchAccess
-
-  validates :access_level, presence: true, inclusion: { in: [Gitlab::Access::MASTER,
-                                                             Gitlab::Access::DEVELOPER] }
-
-  def self.human_access_levels
-    {
-      Gitlab::Access::MASTER => "Masters",
-      Gitlab::Access::DEVELOPER => "Developers + Masters"
-    }.with_indifferent_access
-  end
 end

app/models/protected_branch/push_access_level.rb

@@ -1,21 +1,3 @@
 class ProtectedBranch::PushAccessLevel < ActiveRecord::Base
   include ProtectedBranchAccess
-
-  validates :access_level, presence: true, inclusion: { in: [Gitlab::Access::MASTER,
-                                                             Gitlab::Access::DEVELOPER,
-                                                             Gitlab::Access::NO_ACCESS] }
-
-  def self.human_access_levels
-    {
-      Gitlab::Access::MASTER => "Masters",
-      Gitlab::Access::DEVELOPER => "Developers + Masters",
-      Gitlab::Access::NO_ACCESS => "No one"
-    }.with_indifferent_access
-  end
-
-  def check_access(user)
-    return false if access_level == Gitlab::Access::NO_ACCESS
-
-    super
-  end
 end

changelogs/unreleased/protected-branches-no-one-merge.yml

@@ -0,0 +1,4 @@
+---
+title: Allow 'no one' as an option for allowed to merge on a procted branch
+merge_request:
+author:

spec/features/protected_branches/access_control_ce_spec.rb

@@ -31,7 +31,7 @@ RSpec.shared_examples "protected branches > access control > CE" do
 
       within(".protected-branches-list") do
         find(".js-allowed-to-push").click
-        
+
         within('.js-allowed-to-push-container') do
           expect(first("li")).to have_content("Roles")
           click_on access_type_name