Lib/test/test_pdb.py

   1 # A test suite for pdb; at the moment, this only validates skipping of
   2 # specified test modules (RFE #5142).
   3
   4 import imp
   5 import sys
   6
   7 from test import test_support
   8 # This little helper class is essential for testing pdb under doctest.
   9 from test_doctest import _FakeInput
  10
  11
  12 class PdbTestInput(object):
  13     """Context manager that makes testing Pdb in doctests easier."""
  14
  15     def __init__(self, input):
  16         self.input = input
  17
  18     def __enter__(self):
  19         self.real_stdin = sys.stdin
  20         sys.stdin = _FakeInput(self.input)
  21
  22     def __exit__(self, *exc):
  23         sys.stdin = self.real_stdin
  24
  25
  26 def write(x):
  27     print x
  28
  29 def test_pdb_displayhook():
  30     """This tests the custom displayhook for pdb.
  31
  32     >>> def test_function(foo, bar):
  33     ...     import pdb; pdb.Pdb().set_trace()
  34     ...     pass
  35
  36     >>> with PdbTestInput([
  37     ...     'foo',
  38     ...     'bar',
  39     ...     'for i in range(5): write(i)',
  40     ...     'continue',
  41     ... ]):
  42     ...     test_function(1, None)
  43     > <doctest test.test_pdb.test_pdb_displayhook[0]>(3)test_function()
  44     -> pass
  45     (Pdb) foo
  46     1
  47     (Pdb) bar
  48     (Pdb) for i in range(5): write(i)
  49     0
  50     1
  51     2
  52     3
  53     4
  54     (Pdb) continue
  55     """
  56
  57
  58 def test_pdb_skip_modules():
  59     """This illustrates the simple case of module skipping.
  60
  61     >>> def skip_module():
  62     ...     import string
  63     ...     import pdb; pdb.Pdb(skip=['string*']).set_trace()
  64     ...     string.lower('FOO')
  65
  66     >>> with PdbTestInput([
  67     ...     'step',
  68     ...     'continue',
  69     ... ]):
  70     ...     skip_module()
  71     > <doctest test.test_pdb.test_pdb_skip_modules[0]>(4)skip_module()
  72     -> string.lower('FOO')
  73     (Pdb) step
  74     --Return--
  75     > <doctest test.test_pdb.test_pdb_skip_modules[0]>(4)skip_module()->None
  76     -> string.lower('FOO')
  77     (Pdb) continue
  78     """
  79
  80
  81 # Module for testing skipping of module that makes a callback
  82 mod = imp.new_module('module_to_skip')
  83 exec 'def foo_pony(callback): x = 1; callback(); return None' in mod.__dict__
  84
  85
  86 def test_pdb_skip_modules_with_callback():
  87     """This illustrates skipping of modules that call into other code.
  88
  89     >>> def skip_module():
  90     ...     def callback():
  91     ...         return None
  92     ...     import pdb; pdb.Pdb(skip=['module_to_skip*']).set_trace()
  93     ...     mod.foo_pony(callback)
  94
  95     >>> with PdbTestInput([
  96     ...     'step',
  97     ...     'step',
  98     ...     'step',
  99     ...     'step',
 100     ...     'step',
 101     ...     'continue',
 102     ... ]):
 103     ...     skip_module()
 104     ...     pass  # provides something to "step" to
 105     > <doctest test.test_pdb.test_pdb_skip_modules_with_callback[0]>(5)skip_module()
 106     -> mod.foo_pony(callback)
 107     (Pdb) step
 108     --Call--
 109     > <doctest test.test_pdb.test_pdb_skip_modules_with_callback[0]>(2)callback()
 110     -> def callback():
 111     (Pdb) step
 112     > <doctest test.test_pdb.test_pdb_skip_modules_with_callback[0]>(3)callback()
 113     -> return None
 114     (Pdb) step
 115     --Return--
 116     > <doctest test.test_pdb.test_pdb_skip_modules_with_callback[0]>(3)callback()->None
 117     -> return None
 118     (Pdb) step
 119     --Return--
 120     > <doctest test.test_pdb.test_pdb_skip_modules_with_callback[0]>(5)skip_module()->None
 121     -> mod.foo_pony(callback)
 122     (Pdb) step
 123     > <doctest test.test_pdb.test_pdb_skip_modules_with_callback[1]>(10)<module>()
 124     -> pass  # provides something to "step" to
 125     (Pdb) continue
 126     """
 127
 128
 129 def test_main():
 130     from test import test_pdb
 131     test_support.run_doctest(test_pdb, verbosity=True)
 132
 133
 134 if __name__ == '__main__':
 135     test_main()