tests/test-check-code.t

py3: add "b" prefix to string literals related to module policy

String literals without explicit prefix in __init__.py and policy.py
are treated as unicode object on Python3, because these modules are
loaded before setup of our specific code transformation (the later
module is imported at the beginning of __init__.py).

BTW, "modulepolicy" in __init__.py is initialized by "policy.policy".

This causes issues below;

  - checking "policy" value in other modules causes unintentional result

    For example, "b'py' not in (u'c', u'py')" returns True
    unintentionally on Python3.

  - writing "policy" out fails at conversion from unicode to bytes

    62939e0148f1 fixed this issue for default code path, but "policy"
    can be overridden by HGMODULEPOLICY environment variable (it should
    be rare case for developer using Python3, though).

This patch does:

  - add "b" prefix to all string literals, which are related to module
    policy, in modules above.

  - check existence of HGMODULEPOLICY, and overwrite "policy" only if
    it exists

    For simplicity, this patch omits checking "supports_bytes_environ",
    switching os.environ/os.environb, and so on (Yuya agreed this in
    personal talking)

#require test-repo

  $ . "$TESTDIR/helpers-testrepo.sh"
  $ check_code="$TESTDIR"/../contrib/check-code.py
  $ cd "$TESTDIR"/..

New errors are not allowed. Warnings are strongly discouraged.
(The writing "no-che?k-code" is for not skipping this file when checking.)

  $ hg locate -X contrib/python-zstandard -X hgext/fsmonitor/pywatchman |
  > sed 's-\\-/-g' | xargs "$check_code" --warnings --per-file=0 || false
  Skipping i18n/polib.py it has no-che?k-code (glob)
  mercurial/demandimport.py:312:
   >     if os.environ.get('HGDEMANDIMPORT') != 'disable':
   use encoding.environ instead (py3)
  mercurial/encoding.py:54:
   >     environ = os.environ
   use encoding.environ instead (py3)
  mercurial/encoding.py:56:
   >     environ = os.environb
   use encoding.environ instead (py3)
  mercurial/encoding.py:61:
   >                    for k, v in os.environ.items())
   use encoding.environ instead (py3)
  mercurial/encoding.py:203:
   >                    for k, v in os.environ.items())
   use encoding.environ instead (py3)
  Skipping mercurial/httpclient/__init__.py it has no-che?k-code (glob)
  Skipping mercurial/httpclient/_readers.py it has no-che?k-code (glob)
  mercurial/policy.py:46:
   >     if 'HGMODULEPOLICY' in os.environ:
   use encoding.environ instead (py3)
  mercurial/policy.py:47:
   >         policy = os.environ['HGMODULEPOLICY'].encode('utf-8')
   use encoding.environ instead (py3)
  mercurial/policy.py:49:
   >     policy = os.environ.get('HGMODULEPOLICY', policy)
   use encoding.environ instead (py3)
  Skipping mercurial/statprof.py it has no-che?k-code (glob)
  [1]

@commands in debugcommands.py should be in alphabetical order.

  >>> import re
  >>> commands = []
  >>> with open('mercurial/debugcommands.py', 'rb') as fh:
  ...     for line in fh:
  ...         m = re.match("^@command\('([a-z]+)", line)
  ...         if m:
  ...             commands.append(m.group(1))
  >>> scommands = list(sorted(commands))
  >>> for i, command in enumerate(scommands):
  ...     if command != commands[i]:
  ...         print('commands in debugcommands.py not sorted; first differing '
  ...               'command is %s; expected %s' % (commands[i], command))
  ...         break