1 files changed, 73 insertions, 0 deletions
diff --git a/lib/gitlab/background_migration/add_modified_to_approval_merge_request_rule.rb b/lib/gitlab/background_migration/add_modified_to_approval_merge_request_rule.rb
new file mode 100644
index 00000000000..2148e96f6b4
--- /dev/null
+++ b/lib/gitlab/background_migration/add_modified_to_approval_merge_request_rule.rb
@@ -0,0 +1,73 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    # Compare all current rules to project rules
+    class AddModifiedToApprovalMergeRequestRule
+      # Stubbed class to access the Group table
+      class Group < ActiveRecord::Base
+        self.table_name = 'namespaces'
+        self.inheritance_column = :_type_disabled
+      end
+
+      # Stubbed class to access the ApprovalMergeRequestRule table
+      class ApprovalMergeRequestRule < ActiveRecord::Base
+        self.table_name = 'approval_merge_request_rules'
+
+        has_one :approval_merge_request_rule_source, class_name: 'AddModifiedToApprovalMergeRequestRule::ApprovalMergeRequestRuleSource'
+        has_one :approval_project_rule, through: :approval_merge_request_rule_source
+        has_and_belongs_to_many :groups,
+          class_name: 'AddModifiedToApprovalMergeRequestRule::Group', join_table: "#{self.table_name}_groups"
+      end
+
+      # Stubbed class to access the ApprovalProjectRule table
+      class ApprovalProjectRule < ActiveRecord::Base
+        self.table_name = 'approval_project_rules'
+
+        has_many :approval_merge_request_rule_sources, class_name: 'AddModifiedToApprovalMergeRequestRule::ApprovalMergeRequestRuleSource'
+        has_and_belongs_to_many :groups,
+          class_name: 'AddModifiedToApprovalMergeRequestRule::Group', join_table: "#{self.table_name}_groups"
+      end
+
+      # Stubbed class to access the ApprovalMergeRequestRuleSource table
+      class ApprovalMergeRequestRuleSource < ActiveRecord::Base
+        self.table_name = 'approval_merge_request_rule_sources'
+
+        belongs_to :approval_merge_request_rule, class_name: 'AddModifiedToApprovalMergeRequestRule::ApprovalMergeRequestRule'
+        belongs_to :approval_project_rule, class_name: 'AddModifiedToApprovalMergeRequestRule::ApprovalProjectRule'
+      end
+
+      def perform(start_id, stop_id)
+        approval_merge_requests_rules = ApprovalMergeRequestRule
+          .joins(:groups, :approval_merge_request_rule_source)
+          .where(id: start_id..stop_id)
+          .pluck(
+            'approval_merge_request_rule_sources.id as ars_id',
+            'approval_merge_request_rules_groups.id as amrg_id'
+          )
+
+        approval_project_rules = ApprovalProjectRule
+          .joins(:groups, approval_merge_request_rule_sources: :approval_merge_request_rule)
+          .where(approval_merge_request_rules: { id: start_id..stop_id })
+          .pluck(
+            'approval_merge_request_rule_sources.id as ars_id',
+            'approval_project_rules_groups.id as apg_id'
+          )
+
+        different_names_or_approval_sources = ApprovalMergeRequestRule.joins(:approval_project_rule, :approval_merge_request_rule_source)
+          .where(id: start_id..stop_id)
+          .where('approval_merge_request_rules.name != approval_project_rules.name OR ' \
+                'approval_merge_request_rules.approvals_required != approval_project_rules.approvals_required')
+          .pluck('approval_merge_request_rule_sources.id as ars_id')
+
+        intersected_set = approval_merge_requests_rules.to_set ^ approval_project_rules.to_set
+        source_ids = intersected_set.collect { |rule| rule[0] }.uniq
+
+        rule_sources = ApprovalMergeRequestRuleSource.where(id: source_ids + different_names_or_approval_sources)
+        changed_merge_request_rules = ApprovalMergeRequestRule.where(id: rule_sources.select(:approval_merge_request_rule_id))
+
+        changed_merge_request_rules.update_all(modified_from_project_rule: true)
+      end
+    end
+  end
+end