Lib/test/test_repr.py

   1 """
   2   Test cases for the repr module
   3   Nick Mathewson
   4 """
   5
   6 import unittest
   7 from test_support import run_unittest
   8 from repr import repr as r # Don't shadow builtin repr
   9
  10
  11 def nestedTuple(nesting):
  12     t = ()
  13     for i in range(nesting):
  14         t = (t,)
  15     return t
  16
  17 class ReprTests(unittest.TestCase):
  18
  19     def test_string(self):
  20         eq = self.assertEquals
  21         eq(r("abc"), "'abc'")
  22         eq(r("abcdefghijklmnop"),"'abcdefghijklmnop'")
  23
  24         s = "a"*30+"b"*30
  25         expected = `s`[:13] + "..." + `s`[-14:]
  26         eq(r(s), expected)
  27
  28         eq(r("\"'"), repr("\"'"))
  29         s = "\""*30+"'"*100
  30         expected = `s`[:13] + "..." + `s`[-14:]
  31         eq(r(s), expected)
  32
  33     def test_container(self):
  34         eq = self.assertEquals
  35         # Tuples give up after 6 elements
  36         eq(r(()), "()")
  37         eq(r((1,)), "(1,)")
  38         eq(r((1, 2, 3)), "(1, 2, 3)")
  39         eq(r((1, 2, 3, 4, 5, 6)), "(1, 2, 3, 4, 5, 6)")
  40         eq(r((1, 2, 3, 4, 5, 6, 7)), "(1, 2, 3, 4, 5, 6, ...)")
  41
  42         # Lists give up after 6 as well
  43         eq(r([]), "[]")
  44         eq(r([1]), "[1]")
  45         eq(r([1, 2, 3]), "[1, 2, 3]")
  46         eq(r([1, 2, 3, 4, 5, 6]), "[1, 2, 3, 4, 5, 6]")
  47         eq(r([1, 2, 3, 4, 5, 6, 7]), "[1, 2, 3, 4, 5, 6, ...]")
  48
  49         # Dictionaries give up after 4.
  50         eq(r({}), "{}")
  51         d = {'alice': 1, 'bob': 2, 'charles': 3, 'dave': 4}
  52         eq(r(d), "{'alice': 1, 'bob': 2, 'charles': 3, 'dave': 4}")
  53         d['arthur'] = 1
  54         eq(r(d), "{'alice': 1, 'arthur': 1, 'bob': 2, 'charles': 3, ...}")
  55
  56     def test_numbers(self):
  57         eq = self.assertEquals
  58         eq(r(123), repr(123))
  59         eq(r(123L), repr(123L))
  60         eq(r(1.0/3), repr(1.0/3))
  61
  62         n = 10L**100
  63         expected = `n`[:18] + "..." + `n`[-19:]
  64         eq(r(n), expected)
  65
  66     def test_instance(self):
  67         eq = self.assertEquals
  68         i1 = ClassWithRepr("a")
  69         eq(r(i1), repr(i1))
  70
  71         i2 = ClassWithRepr("x"*1000)
  72         expected = `i2`[:13] + "..." + `i2`[-14:]
  73         eq(r(i2), expected)
  74
  75         i3 = ClassWithFailingRepr()
  76         eq(r(i3), ("<ClassWithFailingRepr instance at %x>"%id(i3)))
  77
  78     def test_nesting(self):
  79         eq = self.assertEquals
  80         # everything is meant to give up after 6 levels.
  81         eq(r([[[[[[[]]]]]]]), "[[[[[[[]]]]]]]")
  82         eq(r([[[[[[[[]]]]]]]]), "[[[[[[[...]]]]]]]")
  83
  84         eq(r(nestedTuple(6)), "(((((((),),),),),),)")
  85         eq(r(nestedTuple(7)), "(((((((...),),),),),),)")
  86
  87         eq(r({ nestedTuple(5) : nestedTuple(5) }),
  88            "{((((((),),),),),): ((((((),),),),),)}")
  89         eq(r({ nestedTuple(6) : nestedTuple(6) }),
  90            "{((((((...),),),),),): ((((((...),),),),),)}")
  91
  92         eq(r([[[[[[{}]]]]]]), "[[[[[[{}]]]]]]")
  93         eq(r([[[[[[[{}]]]]]]]), "[[[[[[[...]]]]]]]")
  94
  95
  96 class ClassWithRepr:
  97     def __init__(self, s):
  98         self.s = s
  99     def __repr__(self):
 100         return "ClassWithLongRepr(%r)" % self.s
 101
 102
 103 class ClassWithFailingRepr:
 104     def __repr__(self):
 105         raise Exception("This should be caught by Repr.repr_instance")
 106
 107
 108 run_unittest(ReprTests)