Add: #600 NGルール (#602)

* Wip

* Wip

* Wip: History

* Wip: テストコード作成

* Fix test

* Wip

* Wip

* Wip

* Fix test

* Wip

* Wip

* Wip

* Wip

* なんとか完成、これから動作確認

* spell miss

* Change ng rule timings

* Fix test

* Wip

* Fix test

* Wip

* Fix form

* 表示まわりの改善

spec/lib/vacuum/ng_histories_vacuum_spec.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Vacuum::NgHistoriesVacuum do
+  subject { described_class.new }
+
+  describe '#perform' do
+    let!(:rule_history_old) { Fabricate(:ng_rule_history, created_at: 30.days.ago) }
+    let!(:rule_history_recent) { Fabricate(:ng_rule_history, created_at: 2.days.ago) }
+
+    before do
+      subject.perform
+    end
+
+    it 'deletes old history' do
+      expect { rule_history_old.reload }.to raise_error ActiveRecord::RecordNotFound
+    end
+
+    it 'does not delete recent history' do
+      expect { rule_history_recent.reload }.to_not raise_error
+    end
+  end
+end