mirror of
https://github.com/python/cpython.git
synced 2025-10-31 13:41:24 +00:00
53 lines
1.9 KiB
Python
53 lines
1.9 KiB
Python
#
|
|
# This file is for everybody to add tests for bugs that aren't
|
|
# fixed yet. Please add a test case and appropriate bug description.
|
|
#
|
|
# When you fix one of the bugs, please move the test to the correct
|
|
# test_ module.
|
|
#
|
|
|
|
import unittest
|
|
from test import test_support
|
|
|
|
#
|
|
# One test case for outstanding bugs at the moment:
|
|
#
|
|
|
|
class TestDifflibLongestMatch(unittest.TestCase):
|
|
# From Patch #1678339:
|
|
# The find_longest_match method in the difflib's SequenceMatcher has a bug.
|
|
|
|
# The bug is in turn caused by a problem with creating a b2j mapping which
|
|
# should contain a list of indices for each of the list elements in b.
|
|
# However, when the b2j mapping is being created (this is being done in
|
|
# __chain_b method in the SequenceMatcher) the mapping becomes broken. The
|
|
# cause of this is that for the frequently used elements the list of indices
|
|
# is removed and the element is being enlisted in the populardict mapping.
|
|
|
|
# The test case tries to match two strings like:
|
|
# abbbbbb.... and ...bbbbbbc
|
|
|
|
# The number of b is equal and the find_longest_match should have returned
|
|
# the proper amount. However, in case the number of "b"s is large enough, the
|
|
# method reports that the length of the longest common substring is 0. It
|
|
# simply can't find it.
|
|
|
|
# A bug was raised some time ago on this matter. It's ID is 1528074.
|
|
|
|
def test_find_longest_match(self):
|
|
import difflib
|
|
for i in (190, 200, 210):
|
|
text1 = "a" + "b"*i
|
|
text2 = "b"*i + "c"
|
|
m = difflib.SequenceMatcher(None, text1, text2)
|
|
(aptr, bptr, l) = m.find_longest_match(0, len(text1), 0, len(text2))
|
|
self.assertEquals(i, l)
|
|
self.assertEquals(aptr, 1)
|
|
self.assertEquals(bptr, 0)
|
|
|
|
|
|
def test_main():
|
|
test_support.run_unittest(TestDifflibLongestMatch)
|
|
|
|
if __name__ == "__main__":
|
|
test_main()
|