Compatibility switch for approval related methods

Only call ApprovalState when enabled

ee/app/models/concerns/approvable_for_rule.rb

+# frozen_string_literal: true
+
+module ApprovableForRule
+  include VisibleApprovableForRule
+
+  FORWARDABLE_METHODS = %w{
+    approval_needed?
+    approved?
+    approvals_left
+    can_approve?
+    has_approved?
+    any_approver_allowed?
+    authors_can_approve?
+  }.freeze
+
+  FORWARDABLE_METHODS.each do |method|
+    define_method(method) do |*args|
+      return super(*args) if ::Feature.disabled?(:approval_rule)
+
+      approval_state.public_send(method, *args) # rubocop:disable GitlabSecurity/PublicSend
+    end
+  end
+
+  def approvers_overwritten?
+    return super if ::Feature.disabled?(:approval_rule)
+
+    approval_state.approval_rules_overwritten?
+  end
+end

ee/app/models/concerns/visible_approvable_for_rule.rb

+# frozen_string_literal: true
+
+# This module may only be used by presenters or modules
+# that include the Approvable concern
+module VisibleApprovableForRule
+  def approvers_left
+    return super if ::Feature.disabled?(:approval_rule)
+
+    approval_state.unactioned_approvers
+  end
+
+  def overall_approvers(exclude_code_owners: false)
+    return super if ::Feature.disabled?(:approval_rule)
+
+    options = { target: :users }
+    options[:code_owner] = false if exclude_code_owners
+
+    approvers = approval_state.filtered_approvers(options)
+    approvers.uniq!
+    approvers
+  end
+
+  def all_approvers_including_groups
+    return super if ::Feature.disabled?(:approval_rule)
+
+    approval_state.approvers
+  end
+
+  def approvers_from_groups
+    return super if ::Feature.disabled?(:approval_rule)
+
+    groups = approval_state.wrapped_approval_rules.flat_map(&:groups)
+    User.joins(:group_members).where(members: { source_id: groups })
+  end
+end

ee/app/models/ee/merge_request.rb

@@ -7,6 +7,7 @@ module EE
 
     include ::Approvable
     include ::Gitlab::Utils::StrongMemoize
+    prepend ApprovableForRule
 
     prepended do
       include Elastic::MergeRequestsSearch

ee/app/presenters/ee/merge_request_presenter.rb

@@ -3,6 +3,7 @@
 module EE
   module MergeRequestPresenter
     include ::VisibleApprovable
+    prepend VisibleApprovableForRule
 
     def approvals_path
       if requires_approve?

ee/spec/models/approvable_spec.rb

@@ -5,6 +5,10 @@ describe Approvable do
   let(:project) { merge_request.project }
   let(:author) { merge_request.author }
 
+  before do
+    stub_feature_flags(approval_rule: false)
+  end
+
   describe '#approvers_overwritten?' do
     subject { merge_request.approvers_overwritten? }
 

ee/spec/models/visible_approvable_spec.rb

@@ -5,6 +5,10 @@ describe VisibleApprovable do
   let!(:project) { create(:project, :repository) }
   let!(:user) { project.creator }
 
+  before do
+    stub_feature_flags(approval_rule: false)
+  end
+
   describe '#requires_approve' do
     subject { resource.requires_approve? }