Add approval status checks to the MR compliance entity

- Added approval status to the MR compliance entity
- Updated the MR compliance entity rspec tests
- Added changelog

ee/app/models/ee/merge_request.rb

@@ -36,6 +36,7 @@ module EE
       delegate :sha, to: :head_pipeline, prefix: :head_pipeline, allow_nil: true
       delegate :sha, to: :base_pipeline, prefix: :base_pipeline, allow_nil: true
       delegate :merge_requests_author_approval?, to: :target_project, allow_nil: true
+      delegate :merge_requests_disable_committers_approval?, to: :target_project, allow_nil: true
 
       scope :without_approvals, -> { left_outer_joins(:approvals).where(approvals: { id: nil }) }
       scope :with_approvals, -> { joins(:approvals) }

ee/app/serializers/merge_request_compliance_entity.rb

@@ -3,6 +3,10 @@
 class MergeRequestComplianceEntity < Grape::Entity
   include RequestAwareEntity
 
+  SUCCESS_APPROVAL_STATUS = :success
+  WARNING_APPROVAL_STATUS = :warning
+  FAILED_APPROVAL_STATUS = :failed
+
   expose :id
   expose :title
   expose :merged_at
@@ -21,6 +25,8 @@ class MergeRequestComplianceEntity < Grape::Entity
 
   expose :pipeline_status, if: -> (*) { can_read_pipeline? }, with: DetailedStatusEntity
 
+  expose :approval_status
+
   private
 
   alias_method :merge_request, :object
@@ -32,4 +38,19 @@ class MergeRequestComplianceEntity < Grape::Entity
   def pipeline_status
     merge_request.head_pipeline.detailed_status(request.current_user)
   end
+
+  def approval_status
+    # All these checks should be false for this to pass as a success
+    # If any are true then there is a violation of the separation of duties
+    checks = [
+        merge_request.authors_can_approve?,
+        merge_request.committers_can_approve?,
+        merge_request.approvals_required < 2
+    ]
+
+    return FAILED_APPROVAL_STATUS if checks.all?
+    return WARNING_APPROVAL_STATUS if checks.any?
+
+    SUCCESS_APPROVAL_STATUS
+  end
 end

ee/changelogs/unreleased/217939-add-mr-approval-settings-to-mr-entity.yml

+---
+title: Add MR approval status to the MR compliance entity
+merge_request: 36824
+author:
+type: added

ee/spec/serializers/merge_request_compliance_entity_spec.rb

@@ -17,7 +17,7 @@ RSpec.describe MergeRequestComplianceEntity do
 
     it 'includes merge request attributes for compliance' do
       expect(subject).to include(
-        :id, :title, :merged_at, :milestone, :path, :issuable_reference, :author, :approved_by_users
+        :id, :title, :merged_at, :milestone, :path, :issuable_reference, :author, :approved_by_users, :approval_status
       )
     end
 
@@ -57,5 +57,45 @@ RSpec.describe MergeRequestComplianceEntity do
         end
       end
     end
+
+    context 'with an approval status' do
+      let_it_be(:committers_approval_enabled) { false }
+      let_it_be(:authors_approval_enabled) { false }
+      let_it_be(:approvals_required) { 2 }
+
+      shared_examples 'the approval status' do
+        before do
+          allow(merge_request).to receive(:authors_can_approve?).and_return(authors_approval_enabled)
+          allow(merge_request).to receive(:committers_can_approve?).and_return(committers_approval_enabled)
+          allow(merge_request).to receive(:approvals_required).and_return(approvals_required)
+        end
+
+        it 'is correct' do
+          expect(subject[:approval_status]).to eq(status)
+        end
+      end
+
+      context 'all approval checks pass' do
+        let_it_be(:status) { :success }
+
+        it_behaves_like 'the approval status'
+      end
+
+      context 'only some of the approval checks pass' do
+        let_it_be(:authors_approval_enabled) { true }
+        let_it_be(:status) { :warning }
+
+        it_behaves_like 'the approval status'
+      end
+
+      context 'none of the approval checks pass' do
+        let_it_be(:committers_approval_enabled) { true }
+        let_it_be(:authors_approval_enabled) { true }
+        let_it_be(:approvals_required) { 0 }
+        let_it_be(:status) { :failed }
+
+        it_behaves_like 'the approval status'
+      end
+    end
   end
 end