#378

backend/spec/models/tag_spec.rb

@@ -1,6 +1,79 @@
 require 'rails_helper'
 
 RSpec.describe Tag, type: :model do
+  describe '.normalise_tags!' do
+    it 'rejects deprecated tags when deny_deprecated is enabled' do
+      tag_name = TagName.create!(name: 'normalise deprecated tag')
+      deprecated_tag = Tag.create!(
+        tag_name:,
+        category: :general,
+        deprecated_at: 1.day.from_now
+      )
+
+      expect {
+        described_class.normalise_tags!(
+          [deprecated_tag.name],
+          deny_deprecated: true
+        )
+      }.to raise_error(Tag::DeprecatedTagNormalisationError) { |error|
+        expect(error.tag_names).to eq([deprecated_tag.name])
+      }
+    end
+  end
+
+  describe '.expand_parent_tags' do
+    it 'expands through multiple deprecated parents to an active ancestor' do
+      child = create(:tag, name: 'expand_child')
+      deprecated_parent = create(
+        :tag,
+        name: 'expand_deprecated_parent',
+        deprecated_at: Time.current
+      )
+      deprecated_grandparent = create(
+        :tag,
+        name: 'expand_deprecated_grandparent',
+        deprecated_at: Time.current
+      )
+      active_ancestor = create(:tag, name: 'expand_active_ancestor')
+      TagImplication.create!(tag: child, parent_tag: deprecated_parent)
+      TagImplication.create!(tag: deprecated_parent, parent_tag: deprecated_grandparent)
+      TagImplication.create!(tag: deprecated_grandparent, parent_tag: active_ancestor)
+
+      expanded = described_class.expand_parent_tags([child])
+
+      expect(expanded).to include(
+        child,
+        deprecated_parent,
+        deprecated_grandparent,
+        active_ancestor
+      )
+      expect(expanded.reject(&:deprecated?)).to contain_exactly(child, active_ancestor)
+    end
+
+    it 'terminates when implications contain a cycle' do
+      first = create(:tag, name: 'expand_cycle_first')
+      second = create(:tag, name: 'expand_cycle_second')
+      TagImplication.create!(tag: first, parent_tag: second)
+      TagImplication.create!(tag: second, parent_tag: first)
+
+      expect(described_class.expand_parent_tags([first])).to contain_exactly(first, second)
+    end
+  end
+
+  describe 'deprecated validation' do
+    it 'rejects deprecated nico tags' do
+      tag = build(
+        :tag,
+        name: 'nico:deprecated_validation',
+        category: :nico,
+        deprecated_at: Time.current
+      )
+
+      expect(tag).not_to be_valid
+      expect(tag.errors[:deprecated_at]).to include('ニコタグは廃止できません．')
+    end
+  end
+
   describe '.merge_tags!' do
     let!(:target_tag) { create(:tag, category: :general) }
     let!(:source_tag) { create(:tag, category: :general) }