hgext/hooklib/changeset_obsoleted.py

typing: add `from __future__ import annotations` to most files

Now that py36 is no longer supported, we can postpone annotation evaluation.
This means that the quoting is usually optional (for things imported under the
guard of `if typing.TYPE_CHECKING:` to avoid circular imports), and there's less
overhead on startup[1].

There may be some missing here.  I backed out 6000f5b25c9b (which removed the
`from __future__ import ...` that was supporting py2), reverted the changes in
`contrib/`, `doc/`, and `tests/`, and then ran:

    $ hg status -n --change . | \
        xargs sed -i -e 's/from __future__ import .*$/from __future__ import annotations/'

There were some minor tweaks needed when reviewing (mostly making the spacing
around the import consistent, and `mercurial/testing/__init__.py` had a
multiline import that wasn't fully rewritten.

[1] https://docs.python.org/3/whatsnew/3.7.html#pep-563-postponed-evaluation-of-annotations

# Copyright 2020 Joerg Sonnenberger <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""changeset_obsoleted is a hook to send a mail when an
existing draft changeset is obsoleted by an obsmarker without successor.

Correct message threading requires the same messageidseed to be used for both
the original notification and the new mail.

Usage:
  [notify]
  messageidseed = myseed

  [hooks]
  txnclose.changeset_obsoleted = \
    python:hgext.hooklib.changeset_obsoleted.hook
"""

from __future__ import annotations

import email.errors as emailerrors
import email.utils as emailutils

from mercurial.i18n import _
from mercurial import (
    encoding,
    error,
    formatter,
    logcmdutil,
    mail,
    obsutil,
    pycompat,
    registrar,
)
from mercurial.utils import (
    dateutil,
    stringutil,
)
from .. import notify

configtable = {}
configitem = registrar.configitem(configtable)

configitem(
    b'notify_obsoleted',
    b'domain',
    default=None,
)
configitem(
    b'notify_obsoleted',
    b'messageidseed',
    default=None,
)
configitem(
    b'notify_obsoleted',
    b'template',
    default=b'''Subject: changeset abandoned

This changeset has been abandoned.
''',
)


def _report_commit(ui, repo, ctx):
    domain = ui.config(b'notify_obsoleted', b'domain') or ui.config(
        b'notify', b'domain'
    )
    messageidseed = ui.config(
        b'notify_obsoleted', b'messageidseed'
    ) or ui.config(b'notify', b'messageidseed')
    template = ui.config(b'notify_obsoleted', b'template')
    spec = formatter.literal_templatespec(template)
    templater = logcmdutil.changesettemplater(ui, repo, spec)
    ui.pushbuffer()
    n = notify.notifier(ui, repo, b'incoming')

    subs = set()
    for sub, spec in n.subs:
        if spec is None:
            subs.add(sub)
            continue
        revs = repo.revs(b'%r and %d:', spec, ctx.rev())
        if len(revs):
            subs.add(sub)
            continue
    if len(subs) == 0:
        ui.debug(
            b'notify_obsoleted: no subscribers to selected repo and revset\n'
        )
        return

    templater.show(
        ctx,
        changes=ctx.changeset(),
        baseurl=ui.config(b'web', b'baseurl'),
        root=repo.root,
        webroot=n.root,
    )
    data = ui.popbuffer()

    try:
        msg = mail.parsebytes(data)
    except emailerrors.MessageParseError as inst:
        raise error.Abort(stringutil.forcebytestr(inst))

    msg['In-reply-to'] = notify.messageid(ctx, domain, messageidseed)
    msg['Message-Id'] = notify.messageid(
        ctx, domain, messageidseed + b'-obsoleted'
    )
    msg['Date'] = encoding.strfromlocal(
        dateutil.datestr(format=b"%a, %d %b %Y %H:%M:%S %1%2")
    )
    if not msg['From']:
        sender = ui.config(b'email', b'from') or ui.username()
        if b'@' not in sender or b'@localhost' in sender:
            sender = n.fixmail(sender)
        msg['From'] = mail.addressencode(ui, sender, n.charsets, n.test)
    msg['To'] = ', '.join(sorted(subs))

    msgtext = msg.as_bytes()
    if ui.configbool(b'notify', b'test'):
        ui.write(msgtext)
        if not msgtext.endswith(b'\n'):
            ui.write(b'\n')
    else:
        ui.status(_(b'notify_obsoleted: sending mail for %d\n') % ctx.rev())
        mail.sendmail(
            ui, emailutils.parseaddr(msg['From'])[1], subs, msgtext, mbox=n.mbox
        )


def has_successor(repo, rev):
    return any(
        r for r in obsutil.allsuccessors(repo.obsstore, [rev]) if r != rev
    )


def hook(ui, repo, hooktype, node=None, **kwargs):
    if hooktype != b"txnclose":
        raise error.Abort(
            _(b'Unsupported hook type %r') % pycompat.bytestr(hooktype)
        )
    for rev in obsutil.getobsoleted(repo, changes=kwargs['changes']):
        ctx = repo.unfiltered()[rev]
        if not has_successor(repo, ctx.node()):
            _report_commit(ui, repo, ctx)