Load locale files for available locales only

lib/faker.rb

@@ -13,11 +13,19 @@ module Faker
 
   class << self
     def load_i18n
-      unless @i18n_loaded
+      return if @i18n_loaded
+
+      if I18n.available_locales&.any?
+        # We expect all locale .yml files to have the locale name in its filename
+        I18n.load_path += ::Dir[::File.join(__dir__, 'locales', "{#{I18n.available_locales.join(',')}}.yml")]
+        # Or to be located in a directory with the locale name
+        I18n.load_path += ::Dir[::File.join(__dir__, 'locales', "{#{I18n.available_locales.join(',')}}/*.yml")]
+      else
         I18n.load_path += ::Dir[::File.join(__dir__, 'locales', '**/*.yml')]
-        I18n.reload! if I18n.backend.initialized?
-        @i18n_loaded = true
       end
+
+      I18n.reload! if I18n.backend.initialized?
+      @i18n_loaded = true
     end
   end
 

test/test_locale.rb

@@ -78,4 +78,19 @@ def test_regex
   def test_available_locales
     assert I18n.locale_available?('en-GB')
   end
+
+  def test_load_i18n
+    Faker.instance_variable_set :@i18n_loaded, nil
+    available_locales_was = I18n.available_locales
+
+    I18n.available_locales = %i[en ja id]
+    Faker.load_i18n
+    I18n.eager_load!
+
+    assert Faker.instance_variable_get(:@i18n_loaded)
+    assert_equal %i[en id ja], I18n.backend.translations.keys.sort
+  ensure
+    I18n.available_locales = available_locales_was
+    Faker.instance_variable_set :@i18n_loaded, nil
+  end
 end