Improve locale selection algorithm

Don't include locales which only have rails translations in
the candidates, and ensure that user specified options take
priority over less specific variants of earlier choices.

diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 307a23f4b035c56539cc9d7dd2d7c841252758f0..6a1338851ba23fcd40e0373d55658152938efaf7 100644 (file)
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -18,7 +18,7 @@ require:
 # Configuration parameters: AutoCorrect, AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
 # URISchemes: http, https
 Layout/LineLength:
-  Max: 260
+  Max: 370
 
 # Offense count: 35
 # Configuration parameters: AllowSafeAssignment.

diff --git a/lib/locale.rb b/lib/locale.rb
index e10f066329a0fd4e126d1416c55271f86fbc564b..b0ad20fc793f4bd4332057af1002c38a39e3cfdd 100644 (file)
--- a/lib/locale.rb
+++ b/lib/locale.rb
@@ -15,7 +15,11 @@ class Locale < I18n::Locale::Tag::Rfc4646
     end
 
     def expand
-      map(&:candidates).flatten.uniq << Locale.default
+      List.new(reverse.each_with_object([]) do |locale, expanded|
+                 locale.candidates.uniq.reverse_each do |candidate|
+                   expanded << candidate if candidate == locale || !expanded.include?(candidate)
+                 end
+               end.reverse.uniq << Locale.default)
     end
   end
 
@@ -28,17 +32,23 @@ class Locale < I18n::Locale::Tag::Rfc4646
   end
 
   def self.available
-    @available ||= List.new(I18n.available_locales)
+    @available ||= List.new(I18n.available_locales).reject!(&:invalid?)
+  end
+
+  def invalid?
+    I18n.t("activerecord.models.acl", :locale => self, :fallback => false, :raise => true).nil?
+  rescue I18n::MissingTranslationData
+    true
   end
 
   def candidates
-    [self.class.new(language, script, region, variant),
-     self.class.new(language, script, region),
-     self.class.new(language, script, nil, variant),
-     self.class.new(language, script),
-     self.class.new(language, nil, region, variant),
-     self.class.new(language, nil, region),
-     self.class.new(language, nil, nil, variant),
-     self.class.new(language)]
+    List.new([self.class.new(language, script, region, variant),
+              self.class.new(language, script, region),
+              self.class.new(language, script, nil, variant),
+              self.class.new(language, script),
+              self.class.new(language, nil, region, variant),
+              self.class.new(language, nil, region),
+              self.class.new(language, nil, nil, variant),
+              self.class.new(language)])
   end
 end

diff --git a/test/integration/user_creation_test.rb b/test/integration/user_creation_test.rb
index b825990b8153293809393ce0c17384fdf2b33837..9c934dc072282f8c8ac590435d34d546d652662c 100644 (file)
--- a/test/integration/user_creation_test.rb
+++ b/test/integration/user_creation_test.rb
@@ -32,7 +32,7 @@ class UserCreationTest < ActionDispatch::IntegrationTest
   end
 
   def test_user_create_submit_duplicate_email
-    I18n.available_locales.each do |locale|
+    Locale.available.each do |locale|
       dup_email = create(:user).email
       display_name = "#{locale}_new_tester"
       assert_difference("User.count", 0) do
@@ -50,7 +50,7 @@ class UserCreationTest < ActionDispatch::IntegrationTest
       end
       assert_response :success
       assert_template "users/new"
-      assert_equal locale.to_s, response.headers["Content-Language"] unless locale == :root
+      assert_equal locale.to_s, response.headers["Content-Language"]
       assert_select "form > fieldset > div.standard-form-row > input.field_with_errors#user_email"
       assert_no_missing_translations
     end

diff --git a/test/lib/locale_test.rb b/test/lib/locale_test.rb
index 4d457116013e55ca6c84bfb208018801de3d4136..13df643b25cbb674ba4edc0cf7ff34daa7d924b5 100644 (file)
--- a/test/lib/locale_test.rb
+++ b/test/lib/locale_test.rb
@@ -80,7 +80,7 @@ class LocaleTest < ActiveSupport::TestCase
   end
 
   def test_available
-    assert_equal I18n.available_locales.count, Locale.available.count
+    assert Locale.available.count <= I18n.available_locales.count
   end
 
   def test_preferred
@@ -91,9 +91,7 @@ class LocaleTest < ActiveSupport::TestCase
     assert_equal "de", Locale.available.preferred(Locale.list("zh-Hant", "de")).to_s
     assert_equal "zh-TW", Locale.available.preferred(Locale.list("zh-Hant-TW", "de")).to_s
     assert_equal "zh-TW", Locale.available.preferred(Locale.list("zh-TW", "de")).to_s
-    assert_equal "zh-HK", Locale.available.preferred(Locale.list("yue", "zh-HK", "de")).to_s
-    assert_equal "zh-yue", Locale.available.preferred(Locale.list("yue", "zh-yue", "zh-HK", "de")).to_s
-    assert_equal "zh-yue", Locale.available.preferred(Locale.list("yue", "zh-YUE", "zh-HK", "de")).to_s
+    assert_equal "zh-TW", Locale.available.preferred(Locale.list("zh-HK", "zh-hk", "zh-Hant", "zh-hant", "zh-TW", "zh-tw", "zh", "zh-yue", "yue", "yue-Hant", "yue-HK", "yue-Hans", "zh-classical", "lzh", "ja-Hani", "ko-Hani", "ko_hanja", "vi-Hani", "ja-hani", "ko-hani", "vi-hani", "en-HK", "en-hk", "en-SG", "en-sg", "en-GB", "en-gb", "en-US", "en-us", "en", "ja")).to_s
     assert_equal "en", Locale.available.preferred(Locale.list("yue")).to_s
   end
 end