Allow Rack::Locale to match languages with variants (#190)

Allow Rack::Locale to match languages with variants

Author: rodrigoassis

lib/rack/contrib/locale.rb

@@ -72,9 +72,12 @@ def user_preferred_locale(header)
 
       if I18n.enforce_available_locales
         locale = locales.reverse.find { |locale| I18n.available_locales.any? { |al| match?(al, locale) } }
-        if locale
-          I18n.available_locales.find { |al| match?(al, locale) }
+        matched_locale = I18n.available_locales.find { |al| match?(al, locale) } if locale
+        if !locale && !matched_locale
+          matched_locale = locales.reverse.find { |locale| I18n.available_locales.any? { |al| variant_match?(al, locale) } }
+          matched_locale = matched_locale[0,2] if matched_locale
         end
+        matched_locale
       else
         locales.last
       end
@@ -83,5 +86,9 @@ def user_preferred_locale(header)
     def match?(s1, s2)
       s1.to_s.casecmp(s2.to_s) == 0
     end
+
+    def variant_match?(s1, s2)
+      s1.to_s.casecmp(s2[0,2].to_s) == 0
+    end
   end
 end

test/spec_rack_locale.rb

@@ -71,6 +71,10 @@ def enforce_available_locales(enforce)
       _(response_with_languages('en-gb,en-us;q=0.95;en').body).must_equal('en-gb')
     end
 
+    specify 'should match languages with variants' do
+      _(response_with_languages('pt;Q=0.9,es-CL').body).must_equal('es')
+    end
+
     specify 'should skip * if it is followed by other languages' do
       _(response_with_languages('*,dk;q=0.5').body).must_equal('dk')
     end