tests/test-check-pyflakes.t

ui: remove unreachable branches and function calls from write() (issue6059)

This is at least faster than ui.write() of 4.8.2.

  $ HGRCPATH=/dev/null hg files -R mozilla-central --time >/dev/null
  4.8.2:  time: real 2.340 secs (user 2.310+0.000 sys 0.020+0.000)
  4.9rc0: time: real 2.580 secs (user 2.550+0.000 sys 0.020+0.000)
  this:   time: real 2.230 secs (user 2.210+0.000 sys 0.020+0.000)

Maybe the formatter should own a resolved write() function because it will
just call dest.write(msg) most of the time, but that would be too much for
stable.

#require test-repo pyflakes hg10

  $ . "$TESTDIR/helpers-testrepo.sh"

run pyflakes on all tracked files ending in .py or without a file ending
(skipping binary file random-seed)

  $ cat > test.py <<EOF
  > print(undefinedname)
  > EOF
  $ pyflakes test.py 2>/dev/null | "$TESTDIR/filterpyflakes.py"
  test.py:1: undefined name 'undefinedname'
  
  $ cd "`dirname "$TESTDIR"`"

  $ testrepohg locate 'set:**.py or grep("^#!.*python")' \
  > -X hgext/fsmonitor/pywatchman \
  > -X mercurial/pycompat.py -X contrib/python-zstandard \
  > -X mercurial/thirdparty/cbor \
  > -X mercurial/thirdparty/concurrent \
  > -X mercurial/thirdparty/zope \
  > 2>/dev/null \
  > | xargs pyflakes 2>/dev/null | "$TESTDIR/filterpyflakes.py"