Filter by section to support sectional codeowners

ee/app/models/approval_merge_request_rule.rb

@@ -66,8 +66,7 @@ class ApprovalMergeRequestRule < ApplicationRecord
   scope :for_checks_that_can_be_refreshed, -> { license_compliance.open_merge_requests.with_head_pipeline }
 
   def self.find_or_create_code_owner_rule(merge_request, entry)
-    merge_request.approval_rules.code_owner.where(name: entry.pattern).first_or_create do |rule|
-      rule.section = entry.section
+    merge_request.approval_rules.code_owner.where(name: entry.pattern).where(section: entry.section).first_or_create do |rule|
       rule.rule_type = :code_owner
       rule.code_owner = true # deprecated, replaced with `rule_type: :code_owner`
     end

ee/spec/factories/approval_rules.rb

@@ -11,6 +11,7 @@ FactoryBot.define do
     rule_type { :code_owner }
     code_owner { true } # deprecated, replaced with `rule_type: :code_owner`
     sequence(:name) { |n| "*-#{n}.js" }
+    section { Gitlab::CodeOwners::Entry::DEFAULT_SECTION }
   end
 
   factory :report_approver_rule, parent: :approval_merge_request_rule do

ee/spec/models/approval_merge_request_rule_spec.rb

@@ -169,6 +169,14 @@ RSpec.describe ApprovalMergeRequestRule do
       it 'finds the existing rule' do
         expect(rule).to eq(existing_code_owner_rule)
       end
+
+      context "when the existing rule matches name but not section" do
+        let(:entry) { Gitlab::CodeOwners::Entry.new("*.rb", "@user", "example_section") }
+
+        it "creates a new rule" do
+          expect(rule).not_to eq(existing_code_owner_rule)
+        end
+      end
     end
 
     it 'creates a new rule if it does not exist' do

ee/spec/services/ee/merge_requests/refresh_service_spec.rb

@@ -125,7 +125,7 @@ RSpec.describe MergeRequests::RefreshService do
           end
 
           it_behaves_like 'creates an approval rule based on current diff' do
-            let(:approval_rules_size) { 4 }
+            let(:approval_rules_size) { 5 }
           end
         end
       end