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/models/ng_rule_spec.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe NgRule do
+  describe '#copy!' do
+    let(:original) { Fabricate(:ng_rule, account_domain: 'foo.bar', account_avatar_state: :needed, status_text: 'ohagi', status_mention_threshold: 5, status_allow_follower_mention: false) }
+    let(:copied) { original.copy! }
+
+    it 'saves safely' do
+      expect { copied.save! }.to_not raise_error
+      expect(copied.reload.id).to_not eq original.id
+    end
+
+    it 'saves specified rules' do
+      expect(copied.account_domain).to eq 'foo.bar'
+      expect(copied.account_avatar_state.to_sym).to eq :needed
+      expect(copied.status_text).to eq 'ohagi'
+      expect(copied.status_mention_threshold).to eq 5
+      expect(copied.status_allow_follower_mention).to be false
+    end
+
+    it 'saves default rules' do
+      expect(copied.account_header_state.to_sym).to eq :optional
+      expect(copied.status_spoiler_text).to eq ''
+      expect(copied.status_reference_threshold).to eq(-1)
+    end
+  end
+end