twisted/test/test_hook.py

   1
   2 # Copyright (c) Twisted Matrix Laboratories.
   3 # See LICENSE for details.
   4
   5
   6 """
   7 Test cases for twisted.hook module.
   8 """
   9
  10 from twisted.python import hook
  11 from twisted.trial import unittest
  12
  13 class BaseClass:
  14     """
  15     dummy class to help in testing.
  16     """
  17     def __init__(self):
  18         """
  19         dummy initializer
  20         """
  21         self.calledBasePre = 0
  22         self.calledBasePost = 0
  23         self.calledBase = 0
  24
  25     def func(self, a, b):
  26         """
  27         dummy method
  28         """
  29         assert a == 1
  30         assert b == 2
  31         self.calledBase = self.calledBase + 1
  32
  33
  34 class SubClass(BaseClass):
  35     """
  36     another dummy class
  37     """
  38     def __init__(self):
  39         """
  40         another dummy initializer
  41         """
  42         BaseClass.__init__(self)
  43         self.calledSubPre = 0
  44         self.calledSubPost = 0
  45         self.calledSub = 0
  46
  47     def func(self, a, b):
  48         """
  49         another dummy function
  50         """
  51         assert a == 1
  52         assert b == 2
  53         BaseClass.func(self, a, b)
  54         self.calledSub = self.calledSub + 1
  55
  56 _clean_BaseClass = BaseClass.__dict__.copy()
  57 _clean_SubClass = SubClass.__dict__.copy()
  58
  59 def basePre(base, a, b):
  60     """
  61     a pre-hook for the base class
  62     """
  63     base.calledBasePre = base.calledBasePre + 1
  64
  65 def basePost(base, a, b):
  66     """
  67     a post-hook for the base class
  68     """
  69     base.calledBasePost = base.calledBasePost + 1
  70
  71 def subPre(sub, a, b):
  72     """
  73     a pre-hook for the subclass
  74     """
  75     sub.calledSubPre = sub.calledSubPre + 1
  76
  77 def subPost(sub, a, b):
  78     """
  79     a post-hook for the subclass
  80     """
  81     sub.calledSubPost = sub.calledSubPost + 1
  82
  83 class HookTestCase(unittest.TestCase):
  84     """
  85     test case to make sure hooks are called
  86     """
  87     def setUp(self):
  88         """Make sure we have clean versions of our classes."""
  89         BaseClass.__dict__.clear()
  90         BaseClass.__dict__.update(_clean_BaseClass)
  91         SubClass.__dict__.clear()
  92         SubClass.__dict__.update(_clean_SubClass)
  93
  94     def testBaseHook(self):
  95         """make sure that the base class's hook is called reliably
  96         """
  97         base = BaseClass()
  98         self.assertEqual(base.calledBase, 0)
  99         self.assertEqual(base.calledBasePre, 0)
 100         base.func(1,2)
 101         self.assertEqual(base.calledBase, 1)
 102         self.assertEqual(base.calledBasePre, 0)
 103         hook.addPre(BaseClass, "func", basePre)
 104         base.func(1, b=2)
 105         self.assertEqual(base.calledBase, 2)
 106         self.assertEqual(base.calledBasePre, 1)
 107         hook.addPost(BaseClass, "func", basePost)
 108         base.func(1, b=2)
 109         self.assertEqual(base.calledBasePost, 1)
 110         self.assertEqual(base.calledBase, 3)
 111         self.assertEqual(base.calledBasePre, 2)
 112         hook.removePre(BaseClass, "func", basePre)
 113         hook.removePost(BaseClass, "func", basePost)
 114         base.func(1, b=2)
 115         self.assertEqual(base.calledBasePost, 1)
 116         self.assertEqual(base.calledBase, 4)
 117         self.assertEqual(base.calledBasePre, 2)
 118
 119     def testSubHook(self):
 120         """test interactions between base-class hooks and subclass hooks
 121         """
 122         sub = SubClass()
 123         self.assertEqual(sub.calledSub, 0)
 124         self.assertEqual(sub.calledBase, 0)
 125         sub.func(1, b=2)
 126         self.assertEqual(sub.calledSub, 1)
 127         self.assertEqual(sub.calledBase, 1)
 128         hook.addPre(SubClass, 'func', subPre)
 129         self.assertEqual(sub.calledSub, 1)
 130         self.assertEqual(sub.calledBase, 1)
 131         self.assertEqual(sub.calledSubPre, 0)
 132         self.assertEqual(sub.calledBasePre, 0)
 133         sub.func(1, b=2)
 134         self.assertEqual(sub.calledSub, 2)
 135         self.assertEqual(sub.calledBase, 2)
 136         self.assertEqual(sub.calledSubPre, 1)
 137         self.assertEqual(sub.calledBasePre, 0)
 138         # let the pain begin
 139         hook.addPre(BaseClass, 'func', basePre)
 140         BaseClass.func(sub, 1, b=2)
 141         # sub.func(1, b=2)
 142         self.assertEqual(sub.calledBase, 3)
 143         self.assertEqual(sub.calledBasePre, 1, str(sub.calledBasePre))
 144         sub.func(1, b=2)
 145         self.assertEqual(sub.calledBasePre, 2)
 146         self.assertEqual(sub.calledBase, 4)
 147         self.assertEqual(sub.calledSubPre, 2)
 148         self.assertEqual(sub.calledSub, 3)
 149
 150 testCases = [HookTestCase]