contrib/simplemerge

typing: add type hints to the common posix/windows platform functions

These are done in sync because some platforms have empty implementations, and it
isn't obvious what the types should be without examining the other.  We want the
types aligned, so @overload definitions that differ aren't generated.  The only
differences here are the few methods that unconditionally raise an error are
marked as `NoReturn`, which doesn't seem to bother pytype.

A couple of the posix module functions needed to be updated with a modern
ternary operator, because pytype seems to want to use the type of the second
object in the old `return x and y` style.

#!/usr/bin/env python3

import getopt
import sys

import hgdemandimport

hgdemandimport.enable()

from mercurial.i18n import _
from mercurial import (
    context,
    error,
    fancyopts,
    simplemerge,
    ui as uimod,
    util,
)
from mercurial.utils import procutil, stringutil

options = [
    (b'L', b'label', [], _(b'labels to use on conflict markers')),
    (b'a', b'text', None, _(b'treat all files as text')),
    (b'p', b'print', None, _(b'print results instead of overwriting LOCAL')),
    (b'', b'no-minimal', None, _(b'no effect (DEPRECATED)')),
    (b'h', b'help', None, _(b'display help and exit')),
    (b'q', b'quiet', None, _(b'suppress output')),
]

usage = _(
    b'''simplemerge [OPTS] LOCAL BASE OTHER

    Simple three-way file merge utility with a minimal feature set.

    Apply to LOCAL the changes necessary to go from BASE to OTHER.

    By default, LOCAL is overwritten with the results of this operation.
'''
)


class ParseError(Exception):
    """Exception raised on errors in parsing the command line."""


def showhelp():
    procutil.stdout.write(usage)
    procutil.stdout.write(b'\noptions:\n')

    out_opts = []
    for shortopt, longopt, default, desc in options:
        out_opts.append(
            (
                b'%2s%s'
                % (
                    shortopt and b'-%s' % shortopt,
                    longopt and b' --%s' % longopt,
                ),
                b'%s' % desc,
            )
        )
    opts_len = max([len(opt[0]) for opt in out_opts])
    for first, second in out_opts:
        procutil.stdout.write(b' %-*s  %s\n' % (opts_len, first, second))


def _verifytext(input, ui, quiet=False, allow_binary=False):
    """verifies that text is non-binary (unless opts[text] is passed,
    then we just warn)"""
    if stringutil.binary(input.text()):
        msg = _(b"%s looks like a binary file.") % input.fctx.path()
        if not quiet:
            ui.warn(_(b'warning: %s\n') % msg)
        if not allow_binary:
            sys.exit(1)


try:
    for fp in (sys.stdin, procutil.stdout, sys.stderr):
        procutil.setbinary(fp)

    opts = {}
    try:
        bargv = [a.encode('utf8') for a in sys.argv[1:]]
        args = fancyopts.fancyopts(bargv, options, opts)
    except getopt.GetoptError as e:
        raise ParseError(e)
    if opts[b'help']:
        showhelp()
        sys.exit(0)
    if len(args) != 3:
        raise ParseError(_(b'wrong number of arguments').decode('utf8'))
    mode = b'merge'
    if len(opts[b'label']) > 2:
        mode = b'merge3'
    local, base, other = args
    overrides = opts[b'label']
    if len(overrides) > 3:
        raise error.InputError(b'can only specify three labels.')
    labels = [local, other, base]
    labels[: len(overrides)] = overrides
    local_input = simplemerge.MergeInput(
        context.arbitraryfilectx(local), labels[0]
    )
    other_input = simplemerge.MergeInput(
        context.arbitraryfilectx(other), labels[1]
    )
    base_input = simplemerge.MergeInput(
        context.arbitraryfilectx(base), labels[2]
    )

    quiet = opts.get(b'quiet')
    allow_binary = opts.get(b'text')
    ui = uimod.ui.load()
    _verifytext(local_input, ui, quiet=quiet, allow_binary=allow_binary)
    _verifytext(base_input, ui, quiet=quiet, allow_binary=allow_binary)
    _verifytext(other_input, ui, quiet=quiet, allow_binary=allow_binary)

    merged_text, conflicts = simplemerge.simplemerge(
        local_input,
        base_input,
        other_input,
        mode,
        allow_binary=allow_binary,
    )
    if opts.get(b'print'):
        ui.fout.write(merged_text)
    else:
        util.writefile(local, merged_text)
    sys.exit(1 if conflicts else 0)
except ParseError as e:
    e = stringutil.forcebytestr(e)
    procutil.stdout.write(b"%s: %s\n" % (sys.argv[0].encode('utf8'), e))
    showhelp()
    sys.exit(1)
except error.Abort as e:
    procutil.stderr.write(b"abort: %s\n" % e)
    sys.exit(255)
except KeyboardInterrupt:
    sys.exit(255)