JsLocaleHelper should search for moment.js locale files

moment.js uses a different naming conventions for locale files.
E.g. "zh-zn" instead of "zh_ZN" and "nb" instead of "nb_NO"

This change allows us to use the locale files without renaming which
makes future upgrades of moment.js a lot easier.

lib/js_locale_helper.rb

@@ -123,7 +123,16 @@ module JsLocaleHelper
   end
 
   def self.moment_locale(locale_str)
+    # moment.js uses a different naming scheme for locale files
+    locale_str = locale_str.tr('_', '-').downcase
     filename = Rails.root + "lib/javascripts/moment_locale/#{locale_str}.js"
+
+    unless File.exists?(filename)
+      # try the language without the territory
+      locale_str = locale_str.partition('-').first
+      filename = Rails.root + "lib/javascripts/moment_locale/#{locale_str}.js"
+    end
+
     if File.exists?(filename)
       File.read(filename) << "\n"
     end || ""

spec/components/js_locale_helper_spec.rb

@@ -173,6 +173,16 @@ describe JsLocaleHelper do
       ctx.load(Rails.root + 'app/assets/javascripts/locales/i18n.js')
       ctx.eval(js)
     end
+
+    it "finds moment.js locale file for #{locale[:value]}" do
+      content = JsLocaleHelper.moment_locale(locale[:value])
+
+      if (locale[:value] == 'en')
+        expect(content).to eq('')
+      else
+        expect(content).to_not eq('')
+      end
+    end
   end
 
 end