fixed unit tests

tests/node-test.js

@@ -70,6 +70,8 @@ SOURCE = 'src/md5.js';
 
 require('./worker-test.js');
 
+delete require.cache[require.resolve('./worker-test.js')];
+
 // cover webworker
 JS_MD5_NO_WINDOW = true;
 JS_MD5_NO_NODE_JS = true;

tests/worker-test.js

@@ -1,4 +1,4 @@
-(function () {
+(function (Worker, WORKER, SOURCE) {
   var cases = {
     'd41d8cd98f00b204e9800998ecf8427e': '',
     '9e107d9d372bb6826bd81d3542a419d6': 'The quick brown fox jumps over the lazy dog',
@@ -18,4 +18,4 @@
       });
     });
   });
-})();
+})(Worker, WORKER, SOURCE);