 
   it "$$.read('./temp/test.txt')", co ->
 
-    string = 'a test message'
-
-    yield $$.write './temp/test.txt', string
-
-    cont = yield $$.read './temp/test.txt'
-
-    unless cont == string
+    source = './temp/test.txt'
+    string = 'a test message'
+
+    yield $$.write source, string
+
+    cont = yield $$.read source
+
+    if cont != string
       throw new Error()
 
     # clean

      throw new Error()

    # clean
    yield $$.remove './temp'

  it "$$.isExisted('./temp/existed')", co ->

    source = './temp/existed'

    yield $$.mkdir source

    unless yield $$.isExisted source
      throw new Error()

    # clean
