tests/test-check-help.t

byteify-strings: add support for ignore comments

Our simple token analysis is sometimes not clever enough, we need to be able
to turn off our script for parts of the code.

This change introduces three special comments:

    - `#no-py3-transform` to tell `byteify-strings` ignore the next line
    - `#py3-transform: off` to ignore everything until the end of the file
    - `#py3-transform: on` to stop ignoring

The last two can be particularly useful within Python 2/3 compatibility files.

#require test-repo

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

  $ cat <<'EOF' > scanhelptopics.py
  > from __future__ import absolute_import, print_function
  > import re
  > import sys
  > if sys.platform == "win32":
  >     import msvcrt
  >     import os
  >     msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
  > stdout = getattr(sys.stdout, 'buffer', sys.stdout)
  > topics = set()
  > topicre = re.compile(br':hg:`help ([a-z0-9\-.]+)`')
  > for fname in sys.argv:
  >     with open(fname, 'rb') as f:
  >         topics.update(m.group(1) for m in topicre.finditer(f.read()))
  > for s in sorted(topics):
  >     stdout.write(b'%s\n' % s)
  > EOF

  $ cd "$TESTDIR"/..

Check if ":hg:`help TOPIC`" is valid:
(use "xargs -n1 -t" to see which help commands are executed)

  $ testrepohg files 'glob:{hgdemandimport,hgext,mercurial}/**/*.py' \
  > | sed 's|\\|/|g' \
  > | xargs "$PYTHON" "$TESTTMP/scanhelptopics.py" \
  > | xargs -n1 hg help --config extensions.phabricator= > /dev/null