Lib/test/test_atexit.py

   1 import sys
   2 import unittest
   3 import io
   4 import atexit
   5 from test import support
   6
   7 ### helpers
   8 def h1():
   9     print("h1")
  10
  11 def h2():
  12     print("h2")
  13
  14 def h3():
  15     print("h3")
  16
  17 def h4(*args, **kwargs):
  18     print("h4", args, kwargs)
  19
  20 def raise1():
  21     raise TypeError
  22
  23 def raise2():
  24     raise SystemError
  25
  26 class TestCase(unittest.TestCase):
  27     def setUp(self):
  28         self.stream = io.StringIO()
  29         self.save_stdout, self.save_stderr = sys.stderr, sys.stdout
  30         sys.stdout = sys.stderr = self.stream
  31         atexit._clear()
  32
  33     def tearDown(self):
  34         sys.stdout = self.save_stdout
  35         sys.stderr = self.save_stderr
  36         atexit._clear()
  37
  38     def test_args(self):
  39         # be sure args are handled properly
  40         atexit.register(h1)
  41         atexit.register(h4)
  42         atexit.register(h4, 4, kw="abc")
  43         atexit._run_exitfuncs()
  44
  45         self.assertEqual(self.stream.getvalue(),
  46                             "h4 (4,) {'kw': 'abc'}\nh4 () {}\nh1\n")
  47
  48     def test_badargs(self):
  49         atexit.register(lambda: 1, 0, 0, (x for x in (1,2)), 0, 0)
  50         self.assertRaises(TypeError, atexit._run_exitfuncs)
  51
  52     def test_order(self):
  53         # be sure handlers are executed in reverse order
  54         atexit.register(h1)
  55         atexit.register(h2)
  56         atexit.register(h3)
  57         atexit._run_exitfuncs()
  58
  59         self.assertEqual(self.stream.getvalue(), "h3\nh2\nh1\n")
  60
  61     def test_raise(self):
  62         # be sure raises are handled properly
  63         atexit.register(raise1)
  64         atexit.register(raise2)
  65
  66         self.assertRaises(TypeError, atexit._run_exitfuncs)
  67
  68     def test_stress(self):
  69         a = [0]
  70         def inc():
  71             a[0] += 1
  72
  73         for i in range(128):
  74             atexit.register(inc)
  75         atexit._run_exitfuncs()
  76
  77         self.assertEqual(a[0], 128)
  78
  79     def test_clear(self):
  80         a = [0]
  81         def inc():
  82             a[0] += 1
  83
  84         atexit.register(inc)
  85         atexit._clear()
  86         atexit._run_exitfuncs()
  87
  88         self.assertEqual(a[0], 0)
  89
  90     def test_unregister(self):
  91         a = [0]
  92         def inc():
  93             a[0] += 1
  94         def dec():
  95             a[0] -= 1
  96
  97         for i in range(4):
  98             atexit.register(inc)
  99         atexit.register(dec)
 100         atexit.unregister(inc)
 101         atexit._run_exitfuncs()
 102
 103         self.assertEqual(a[0], -1)
 104
 105     def test_bound_methods(self):
 106         l = []
 107         atexit.register(l.append, 5)
 108         atexit._run_exitfuncs()
 109         self.assertEqual(l, [5])
 110
 111         atexit.unregister(l.append)
 112         atexit._run_exitfuncs()
 113         self.assertEqual(l, [5])
 114
 115
 116 def test_main():
 117     support.run_unittest(TestCase)
 118
 119 if __name__ == "__main__":
 120     test_main()