black: rename pyproject.toml to black.toml

Black won't read this automatically (you'll have to specify --config),
but having a pyproject.toml *at all* puts pip in PEP 517/518 mode
which breaks us for obscure reasons I don't understand. Rather than
waste a ton of time fighting with pip, let's just do this.

Differential Revision: https://phab.mercurial-scm.org/D7087

contrib/examples/fix.hgrc

@@ -1,15 +1,15 b''
 [fix]
 clang-format:command = clang-format --style file -i
 clang-format:pattern = (**.c or **.cc or **.h) and not "listfile:contrib/clang-format-ignorelist"
 
 rustfmt:command = rustfmt {rootpath}
 rustfmt:pattern = set:**.rs
 
 # We use black, but currently with
 # https://github.com/psf/black/pull/826 applied. For now
 # contrib/grey.py is our fork of black. You need to pip install
 # git+https://github.com/python/black/@d9e71a75ccfefa3d9156a64c03313a0d4ad981e5
 # to have the dependencies for grey.
 #
-# black:command = python3.7 contrib/grey.py --quiet --skip-string-normalization -
+# black:command = python3.7 contrib/grey.py --quiet --config=black.toml --skip-string-normalization -
 # black:pattern = set:**.py - hgext/fsmonitor/pywatchman/** - mercurial/thirdparty/** - "contrib/python-zstandard/**"

tests/test-check-code.t

@@ -1,87 +1,87 b''
 #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.)
 
   $ testrepohg locate \
   > -X contrib/python-zstandard \
   > -X hgext/fsmonitor/pywatchman \
   > -X mercurial/thirdparty \
   > | sed 's-\\-/-g' | "$check_code" --warnings --per-file=0 - || false
   Skipping contrib/automation/hgautomation/__init__.py it has no-che?k-code (glob)
   Skipping contrib/automation/hgautomation/aws.py it has no-che?k-code (glob)
   Skipping contrib/automation/hgautomation/cli.py it has no-che?k-code (glob)
   Skipping contrib/automation/hgautomation/linux.py it has no-che?k-code (glob)
   Skipping contrib/automation/hgautomation/pypi.py it has no-che?k-code (glob)
   Skipping contrib/automation/hgautomation/ssh.py it has no-che?k-code (glob)
   Skipping contrib/automation/hgautomation/try_server.py it has no-che?k-code (glob)
   Skipping contrib/automation/hgautomation/windows.py it has no-che?k-code (glob)
   Skipping contrib/automation/hgautomation/winrm.py it has no-che?k-code (glob)
   Skipping contrib/grey.py it has no-che?k-code (glob)
   Skipping contrib/packaging/hgpackaging/downloads.py it has no-che?k-code (glob)
   Skipping contrib/packaging/hgpackaging/inno.py it has no-che?k-code (glob)
   Skipping contrib/packaging/hgpackaging/py2exe.py it has no-che?k-code (glob)
   Skipping contrib/packaging/hgpackaging/util.py it has no-che?k-code (glob)
   Skipping contrib/packaging/hgpackaging/wix.py it has no-che?k-code (glob)
   Skipping contrib/packaging/inno/build.py it has no-che?k-code (glob)
   Skipping contrib/packaging/wix/build.py it has no-che?k-code (glob)
   Skipping i18n/polib.py it has no-che?k-code (glob)
   Skipping mercurial/statprof.py it has no-che?k-code (glob)
   Skipping tests/badserverext.py it has no-che?k-code (glob)
 
 @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(br"^@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
 
 Prevent adding new files in the root directory accidentally.
 
   $ testrepohg files 'glob:*'
   .arcconfig
   .clang-format
   .editorconfig
   .hgignore
   .hgsigs
   .hgtags
   .jshintrc
   CONTRIBUTING
   CONTRIBUTORS
   COPYING
   Makefile
   README.rst
+  black.toml
   hg
   hgeditor
   hgweb.cgi
-  pyproject.toml
   setup.py
 
 Prevent adding modules which could be shadowed by ancient .so/.dylib.
 
   $ testrepohg files \
   > mercurial/base85.py \
   > mercurial/bdiff.py \
   > mercurial/diffhelpers.py \
   > mercurial/mpatch.py \
   > mercurial/osutil.py \
   > mercurial/parsers.py \
   > mercurial/zstd.py
   [1]
 
 Keep python3 tests sorted:
   $ sort < contrib/python3-whitelist > $TESTTMP/py3sorted
   $ cmp contrib/python3-whitelist $TESTTMP/py3sorted || echo 'Please sort passing tests!'