Wiki 依存の排除 (#431) (#432)

Reviewed-on: #432
Co-authored-by: miteruzo <miteruzo@naver.com>

backend/spec/support/ainu_locale_contract.rb

@@ -0,0 +1,22 @@
+RSpec.shared_context 'Ainu locale contract' do
+  let(:ainu_locale) { instance_double(Locale, language_code: 'ain', script_code: 'Jpan') }
+
+  before do
+    # Only the foreign-key reference is seeded; no Locale or enum is enabled.
+    Language.connection.execute(<<~SQL)
+      INSERT IGNORE INTO languages (code, name, created_at)
+      VALUES ('ain', 'Ainu', CURRENT_TIMESTAMP)
+    SQL
+    allow(Locale).to receive(:find_by).and_call_original
+    allow(Locale).to receive(:find_by).with(code: 'ain').and_return(ainu_locale)
+  end
+
+  def add_ainu_name tag, name
+    TagName.insert_all!([{
+        tag_id: tag.id, language_code: 'ain', script_code: 'Jpan', name:,
+        primary_flg: true, auto_generated: false,
+        created_at: Time.current, updated_at: Time.current }])
+    tag.tag_names.reset
+    TagName.find_by!(tag_id: tag.id, language_code: 'ain', name:)
+  end
+end