Merge pull request #129 from prograils/fix/fallback_keys_firing_unnecessary_queries

Fix/fallback keys firing unnecessary queries

Author: mlitwiniuk

lib/lit/i18n_backend.rb

@@ -72,6 +72,7 @@ def lookup(locale, key, scope = [], options = {})
       # check in cache or in simple backend
       content = @cache[key_with_locale] || super
       return content if parts.size <= 1
+
       if content.nil? && should_cache?(key_with_locale, options)
         new_content = @cache.init_key_with_value(key_with_locale, content)
         content = new_content if content.nil? # Content can change when Lit.humanize is true for example
@@ -181,7 +182,7 @@ def is_ignored_key(key_without_locale)
 
     def should_cache?(key_with_locale, options)
       if @cache.has_key?(key_with_locale)
-        return false unless options[:default]
+        return false unless options[:default] && !options[:default].is_a?(Array)
       end
 
       _, key_without_locale = ::Lit::Cache.split_key(key_with_locale)

test/test_helper.rb

@@ -128,3 +128,10 @@ def new_controller_test_format?
 end
 
 MinitestVcr::Spec.configure!
+
+def assert_no_database_queries
+  ActiveRecord::Base.connection.stubs(:execute).
+    raises(Minitest::Assertion, 'The block should not make any database calls')
+  yield
+  ActiveRecord::Base.connection.unstub(:execute)
+end

test/unit/i18n_backend_test.rb

@@ -53,4 +53,23 @@ def teardown
     l = lk.localizations.where(locale: locale).first
     assert_nil l.default_value
   end
+
+  test 'will not call additional queries when nil values in a fallback key chain have been cached' do
+    Lit.humanize_key = false
+    I18n.locale = :en
+
+    test_key = :'test.key'
+    fallback_key = :'test.fallback'
+
+    # first, when these keys don't exist in the DB yet, they should be created:
+    loc_key_count = -> { Lit::LocalizationKey.where(localization_key: [test_key, fallback_key]).count }
+    assert_equal 0, loc_key_count.call
+    assert_equal 'foobar', I18n.t(test_key, default: [fallback_key, 'foobar'])
+    assert_equal 2, loc_key_count.call
+
+    # on subsequent translation calls, they should not be fetched from DB
+    assert_no_database_queries do
+      assert_equal 'foobar', I18n.t(test_key, default: [fallback_key, 'foobar'])
+    end
+  end
 end