 
   it "$$.isExisted('./temp/existed')", co ->
 
-    yield $$.mkdir './temp/existed'
-
-    unless yield $$.isExisted './temp/existed'
+    source = './temp/existed'
+
+    yield $$.mkdir source
+
+    unless yield $$.isExisted source
       throw new Error()
 
     # clean


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

    yield $$.write './temp/existed/existed.txt', 'existed'

    unless yield $$.isExisted './temp/existed/existed.txt'
      throw new Error()

    # clean


  it "$$.read('./temp/test.json')", co ->

    source = './temp/test.json'
    string = 'a test message'
    object = message: string

    yield $$.write source, object

    cont = yield $$.read source

    if cont.message != string
      throw new Error()

    # clean
