Stop modifying locale before sending to Google Translate

lib/i18n/tasks/translators/google_translator.rb

@@ -22,8 +22,8 @@
     def options_for_translate_values(from:, to:, **options)
       options.merge(
         api_key: api_key,
-        from: to_google_translate_compatible_locale(from),
-        to: to_google_translate_compatible_locale(to)
+        from: from,
+        to: to,
       )
     end
 
@@ -41,15 +41,6 @@
 
     private
 
-    SUPPORTED_LOCALES_WITH_REGION = %w[zh-CN zh-TW].freeze
-
-    # Convert 'es-ES' to 'es'
-    def to_google_translate_compatible_locale(locale)
-      return locale unless locale.include?('-') && !SUPPORTED_LOCALES_WITH_REGION.include?(locale)
-
-      locale.split('-', 2).first
-    end
-
     def api_key
       @api_key ||= begin
         key = @i18n_tasks.translation_config[:google_translate_api_key]

spec/google_translate_spec.rb

@@ -67,4 +67,52 @@
       end
     end
   end
+
+  describe 'chinese simplified vs traditional' do
+    delegate :i18n_task, :in_test_app_dir, :run_cmd, to: :TestCodebase
+
+    before do
+      TestCodebase.setup(
+        'config/locales/en.yml' => '',
+        'config/locales/zh.yml' => '',
+        'config/locales/zh-cn.yml' => '',
+        'config/locales/zh-hans.yml' => '',
+        'config/locales/zh-tw.yml' => '',
+        'config/locales/zh-hant.yml' => '',
+        'config/locales/zh-hk.yml' => '',
+        'config/locales/es.yml' => '',
+      )
+    end
+
+    after do
+      TestCodebase.teardown
+    end
+
+    context 'command' do
+      let(:task) { i18n_task }
+
+      it 'should allow google to decide proper language from locale' do
+        skip 'temporarily disabled on JRuby due to https://github.com/jruby/jruby/issues/4802' if RUBY_ENGINE == 'jruby'
+        skip 'GOOGLE_TRANSLATE_API_KEY env var not set' unless ENV['GOOGLE_TRANSLATE_API_KEY']
+        skip 'GOOGLE_TRANSLATE_API_KEY env var is empty' if ENV['GOOGLE_TRANSLATE_API_KEY'].empty?
+        in_test_app_dir do
+          task.data[:en] = build_tree('en' => { 'common' => { 'a' => 'λ', 'horse' => 'horse' } })
+
+          # Loading translations seems to require at least one existing value.
+          %w(zh zh-cn zh-hans zh-tw zh-hant zh-hk).each do |locale|
+            task.data[locale] = build_tree(locale => { 'common' => { 'a' => 'λ' } })
+          end
+
+          run_cmd 'translate-missing'
+
+          expect(task.t('common.horse', 'zh'     )).to eq("马") # Simplified Chinese
+          expect(task.t('common.horse', 'zh-cn'  )).to eq("马") # Simplified Chinese
+          expect(task.t('common.horse', 'zh-hans')).to eq("马") # Simplified Chinese
+          expect(task.t('common.horse', 'zh-tw'  )).to eq("馬") # Traditional Chinese
+          expect(task.t('common.horse', 'zh-hant')).to eq("馬") # Traditional Chinese
+          expect(task.t('common.horse', 'zh-hk'  )).to eq("馬") # Traditional Chinese
+        end
+      end
+    end
+  end
 end