Cleanup internal id records for epics.

db/post_migrate/20180723130817_delete_inconsistent_internal_id_records.rb

@@ -20,6 +20,7 @@ class DeleteInconsistentInternalIdRecords < ActiveRecord::Migration
       delete_internal_id_records('milestones', 'project_id')
       delete_internal_id_records('milestones', 'namespace_id', 'group_id')
       delete_internal_id_records('ci_pipelines', 'project_id')
+      delete_internal_id_records('epics', 'namespace_id', 'group_id')
     end
   end
 

spec/migrations/delete_inconsistent_internal_id_records_spec.rb

@@ -79,7 +79,7 @@ describe DeleteInconsistentInternalIdRecords, :migration do
   end
 
   context 'for milestones (by group)' do
-    # milestones (by group) is a little different than all of the other models
+    # milestones (by group) is a little different than most of the other models
     let!(:group1) { create(:group) }
     let!(:group2) { create(:group) }
     let!(:group3) { create(:group) }
@@ -116,4 +116,43 @@ describe DeleteInconsistentInternalIdRecords, :migration do
       expect { migrate! }.not_to change { internal_id_query.call(group3).size }
     end
   end
+
+  context 'for milestones (by group)' do
+    # epics (by group) is a little different than most of the other models
+    let!(:group1) { create(:group) }
+    let!(:group2) { create(:group) }
+    let!(:group3) { create(:group) }
+
+    let(:internal_id_query) { ->(group) { InternalId.where(usage: InternalId.usages['epics'], namespace: group) } }
+
+    before do
+      create_list(:epic, 3, group: group1)
+      create_list(:epic, 3, group: group2)
+      create_list(:epic, 3, group: group3)
+
+      internal_id_query.call(group1).first.tap do |iid|
+        iid.last_value = iid.last_value - 2
+        # This is an inconsistent record
+        iid.save!
+      end
+
+      internal_id_query.call(group3).first.tap do |iid|
+        iid.last_value = iid.last_value + 2
+        # This is a consistent record
+        iid.save!
+      end
+    end
+
+    it "deletes inconsistent records" do
+      expect { migrate! }.to change { internal_id_query.call(group1).size }.from(1).to(0)
+    end
+
+    it "retains consistent records" do
+      expect { migrate! }.not_to change { internal_id_query.call(group2).size }
+    end
+
+    it "retains consistent records, especially those with a greater last_value" do
+      expect { migrate! }.not_to change { internal_id_query.call(group3).size }
+    end
+  end
 end