tests/filterpyflakes.py

cache: safer handling of failing seek when writing revision branch cache

If the seek for some reason fails (perhaps because the file is too short to
search to the requested position), make sure we seek to the start and rewrite
everything.

It is unknown if this fixes a real problem that ever happened.

#!/usr/bin/env python

# Filter output by pyflakes to control which warnings we check

from __future__ import absolute_import

import re
import sys

def makekey(typeandline):
    """
    for sorting lines by: msgtype, path/to/file, lineno, message

    typeandline is a sequence of a message type and the entire message line
    the message line format is path/to/file:line: message

    >>> makekey((3, 'example.py:36: any message'))
    (3, 'example.py', 36, ' any message')
    >>> makekey((7, 'path/to/file.py:68: dummy message'))
    (7, 'path/to/file.py', 68, ' dummy message')
    >>> makekey((2, 'fn:88: m')) > makekey((2, 'fn:9: m'))
    True
    """

    msgtype, line = typeandline
    fname, line, message = line.split(":", 2)
    # line as int for ordering 9 before 88
    return msgtype, fname, int(line), message


lines = []
for line in sys.stdin:
    # We whitelist tests (see more messages in pyflakes.messages)
    pats = [
            (r"imported but unused", None),
            (r"local variable '.*' is assigned to but never used", None),
            (r"unable to detect undefined names", None),
            (r"undefined name '.*'",
             r"undefined name '(WindowsError|memoryview)'")
           ]

    for msgtype, (pat, excl) in enumerate(pats):
        if re.search(pat, line) and (not excl or not re.search(excl, line)):
            break # pattern matches
    else:
        continue # no pattern matched, next line
    fn = line.split(':', 1)[0]
    f = open(fn)
    data = f.read()
    f.close()
    if 'no-' 'check-code' in data:
        continue
    lines.append((msgtype, line))

for msgtype, line in sorted(lines, key=makekey):
    sys.stdout.write(line)
print

# self test of "undefined name" detection for other than 'memoryview'
if False:
    print undefinedname