making I18n class testable, adding minimal test

js/privatebin.js

@@ -538,6 +538,18 @@ jQuery.PrivateBin = function($, sjcl, Base64, RawDeflate) {
             });
         }
 
+        /**
+         * resets state, used for unit testing
+         *
+         * @name   I18n.reset
+         * @function
+         */
+        me.reset = function()
+        {
+            language = null;
+            translations = {};
+        }
+
         return me;
     })(window, document);
 
@@ -810,7 +822,6 @@ jQuery.PrivateBin = function($, sjcl, Base64, RawDeflate) {
             $cipherData = $templates = id = symmetricKey = null;
         }
 
-
         /**
          * init navigation manager
          *

js/test.js

@@ -270,7 +270,8 @@ describe('Helper', function () {
                     cookieArray = [],
                     count = 0;
                 labels.forEach(function(item, i) {
-                    var key = item.replace(/[\s;,=]/g, 'x'),
+                    // deliberatly using a non-ascii key for replacing invalid characters
+                    var key = item.replace(/[\s;,=]/g, '£'),
                         value = (values[i] || values[0]).replace(/[\s;,=]/g, '');
                     cookieArray.push(key + '=' + value);
                     if (Math.random() < 1 / i)
@@ -325,6 +326,27 @@ describe('Helper', function () {
     });
 });
 
+describe('I18n', function () {
+    describe('translate', function () {
+        before(function () {
+            $.PrivateBin.I18n.reset();
+        });
+
+        jsc.property(
+            'returns message ID unchanged if no translation found',
+            'string',
+            function (messageId) {
+                var result = $.PrivateBin.I18n.translate(messageId);
+                $.PrivateBin.I18n.reset();
+                var alias = $.PrivateBin.I18n._(messageId);
+                $.PrivateBin.I18n.reset();
+                return messageId === result &&
+                    messageId === alias;
+            }
+        );
+    });
+});
+
 describe('Model', function () {
     describe('getPasteId', function () {
         before(function () {