dualfroz
8db541c87e
Inside a character class '|' is a literal, so [+|-] matched '+', '-', or '|'. A leading pipe was captured as a sign and stripped, letting malformed input like '|5m' parse to 300 instead of returning None. Restrict the class to the two intended sign characters.
1.5 KiB
Fix sign character class accidentally matching a pipe |
Problem
timeparse accepts a leading pipe | as though it were a valid sign and
silently parses the rest of the expression, instead of rejecting the malformed
input with None:
>>> from pytimeparse import parse
>>> parse('|5m')
300 # expected None
>>> parse('|1:24')
84 # expected None
Root cause
pytimeparse/timeparse.py:
SIGN = r'(?P<sign>[+|-])?'
Inside a character class, | is a literal character, not the alternation
operator. So [+|-] matches +, -, or |. When the input starts with |,
the sign group captures it, the pipe is stripped from the string, and the
remainder is parsed as if no sign were present (sign resolves to 1 because
'|' != '-').
Fix
Use a character class containing only the two intended sign characters:
SIGN = r'(?P<sign>[+-])?'
Now a leading | is not consumed as a sign; the pipe stays in the string, no
time-format pattern matches it, and timeparse returns None as it does for
any other unparseable input. Valid +/- signs are unaffected.
Test
Extended test_timeparse_signs in pytimeparse/tests/testtimeparse.py:
self.assertIsNone(timeparse.timeparse('|5m'))
self.assertIsNone(timeparse.timeparse('| 5m'))
self.assertIsNone(timeparse.timeparse('|1:24'))
Gate
python -m pytest pytimeparse/tests/testtimeparse.py-> 49 passed.
Counterfactual (fix reverted, test kept): fails with
AssertionError: 300 is not None.