tests/filterpyflakes.py

obsolescence: add test case C-2 for obsolescence markers exchange

About 3 years ago, in August 2014, the logic to select what markers to select on
push was ported from the evolve extension to Mercurial core. However, for some
unclear reasons, the tests for that logic were not ported alongside.
I realised it a couple of weeks ago while working on another push related issue.
I've made a clean up pass on the tests and they are now ready to integrate the
core test suite. This series of changesets do not change any logic. I just adds
test for logic that has been around for about 10 versions of Mercurial.

They are a patch for each test case. It makes it easier to review and postpone
one with documentation issues without rejecting the wholes series.

This patch introduce C-2: Pruned changeset on precursors

Each test case comes it in own test file. It help parallelism and does not
introduce a significant overhead from having a single unified giant test file.
Here are timing  to support this claim.

# Multiple test files version:
# run-tests.py --local -j 1 test-exchange-*.t
53.40s user 6.82s system 85% cpu 1:10.76 total
52.79s user 6.97s system 85% cpu 1:09.97 total
52.94s user 6.82s system 85% cpu 1:09.69 total

# Single test file version:
# run-tests.py --local -j 1 test-exchange-obsmarkers.t
52.97s user 6.85s system 85% cpu 1:10.10 total
52.64s user 6.79s system 85% cpu 1:09.63 total
53.70s user 7.00s system 85% cpu 1:11.17 total

#!/usr/bin/env python

# Filter output by pyflakes to control which warnings we check

from __future__ import absolute_import, print_function

import re
import sys

lines = []
for line in sys.stdin:
    # We blacklist tests that are too noisy for us
    pats = [
        r"undefined name '(WindowsError|memoryview)'",
        r"redefinition of unused '[^']+' from line",
    ]

    keep = True
    for pat in pats:
        if re.search(pat, line):
            keep = False
            break # pattern matches
    if keep:
        fn = line.split(':', 1)[0]
        f = open(fn)
        data = f.read()
        f.close()
        if 'no-' 'check-code' in data:
            continue
        lines.append(line)

for line in lines:
    sys.stdout.write(line)
print()

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