add automatic code format enforcer - black (#813)

* add automatic code format enforcer - black
* convert % to format
* fix double quotes in one line
* some more % to format changes
* use stable release of black
* allow unicode in description

.pre-commit-config.yaml

@@ -1,13 +1,17 @@
 repos:
+-   repo: https://github.com/ambv/black
+    rev: 18.4a4
+    hooks:
+    - id: black
+      args: [--line-length=99, --safe]
+      python_version: python3.6
 -   repo: https://github.com/pre-commit/pre-commit-hooks
-    sha: v1.1.1
+    rev: v1.2.3
     hooks:
-    -   id: trailing-whitespace
-    -   id: end-of-file-fixer
     -   id: check-yaml
     -   id: debug-statements
     -   id: flake8
 -   repo: https://github.com/asottile/pyupgrade
-    sha: v1.2.0
+    rev: v1.2.0
     hooks:
     -   id: pyupgrade

README.rst

@@ -16,6 +16,9 @@
 .. image:: https://readthedocs.org/projects/tox/badge/?version=latest
   :target: http://tox.readthedocs.io/en/latest/?badge=latest
   :alt: Documentation status
+.. image:: https://img.shields.io/badge/code%20style-black-000000.svg
+  :target: https://github.com/ambv/black
+  :alt: Code style: black
 
 tox automation project
 ======================

doc/conf.py

@@ -5,57 +5,59 @@
 from pkg_resources import get_distribution
 
 sys.path.insert(0, os.path.dirname(__file__))
-extensions = ['sphinx.ext.autodoc',
-              'sphinx.ext.extlinks',
-              'sphinx.ext.intersphinx',
-              'sphinx.ext.viewcode']
+extensions = [
+    "sphinx.ext.autodoc", "sphinx.ext.extlinks", "sphinx.ext.intersphinx", "sphinx.ext.viewcode"
+]
 
-project = u'tox'
+project = u"tox"
 _full_version = get_distribution(project).version
-release = _full_version.split('+', 1)[0]
-version = '.'.join(release.split('.')[:2])
+release = _full_version.split("+", 1)[0]
+version = ".".join(release.split(".")[:2])
 
-author = 'holger krekel and others'
+author = "holger krekel and others"
 year = date.today().year
-copyright = u'2010-{}, {}'.format(year, author)
+copyright = u"2010-{}, {}".format(year, author)
 
-master_doc = 'index'
-source_suffix = '.rst'
+master_doc = "index"
+source_suffix = ".rst"
 
-exclude_patterns = ['_build']
+exclude_patterns = ["_build"]
 
-templates_path = ['_templates']
-pygments_style = 'sphinx'
-html_theme = 'alabaster'
-html_logo = 'img/tox.png'
-html_favicon = 'img/toxfavi.ico'
-html_static_path = ['_static']
+templates_path = ["_templates"]
+pygments_style = "sphinx"
+html_theme = "alabaster"
+html_logo = "img/tox.png"
+html_favicon = "img/toxfavi.ico"
+html_static_path = ["_static"]
 html_show_sourcelink = False
-htmlhelp_basename = '{}doc'.format(project)
-latex_documents = [('index', 'tox.tex', u'{} Documentation'.format(project),
-                    author, 'manual')]
-man_pages = [('index', project, u'{} Documentation'.format(project),
-              [author], 1)]
+htmlhelp_basename = "{}doc".format(project)
+latex_documents = [("index", "tox.tex", u"{} Documentation".format(project), author, "manual")]
+man_pages = [("index", project, u"{} Documentation".format(project), [author], 1)]
 epub_title = project
 epub_author = author
 epub_publisher = author
 epub_copyright = copyright
 
-intersphinx_mapping = {'https://docs.python.org/': None}
+intersphinx_mapping = {"https://docs.python.org/": None}
 
 
 def setup(app):
     # from sphinx.ext.autodoc import cut_lines
     # app.connect('autodoc-process-docstring', cut_lines(4, what=['module']))
-    app.add_description_unit('confval', 'confval',
-                             objname='configuration value',
-                             indextemplate='pair: %s; configuration value')
+    app.add_description_unit(
+        "confval",
+        "confval",
+        objname="configuration value",
+        indextemplate="pair: %s; configuration value",
+    )
 
 
-tls_cacerts = os.getenv('SSL_CERT_FILE')  # we don't care here about the validity of certificates
+tls_cacerts = os.getenv("SSL_CERT_FILE")  # we don't care here about the validity of certificates
 linkcheck_timeout = 30
-linkcheck_ignore = [r'http://holgerkrekel.net']
+linkcheck_ignore = [r"http://holgerkrekel.net"]
 
-extlinks = {'issue': ('https://github.com/tox-dev/tox/issues/%s', '#'),
-            'pull': ('https://github.com/tox-dev/tox/pull/%s', 'p'),
-            'user': ('https://github.com/%s', '@')}
+extlinks = {
+    "issue": ("https://github.com/tox-dev/tox/issues/%s", "#"),
+    "pull": ("https://github.com/tox-dev/tox/pull/%s", "p"),
+    "user": ("https://github.com/%s", "@"),
+}

setup.py

@@ -17,66 +17,65 @@ def has_environment_marker_support():
     * https://www.python.org/dev/peps/pep-0426/#environment-markers
     """
     import pkg_resources
+
     try:
         v = pkg_resources.parse_version(setuptools.__version__)
-        return v >= pkg_resources.parse_version('0.7.2')
+        return v >= pkg_resources.parse_version("0.7.2")
     except Exception as e:
-        sys.stderr.write("Could not test setuptool's version: %s\n" % e)
+        sys.stderr.write("Could not test setuptool's version: {}\n".format(e))
         return False
 
 
 def get_long_description():
-    with io.open('README.rst', encoding='utf-8') as f:
-        with io.open('CHANGELOG.rst', encoding='utf-8') as g:
-            return "%s\n\n%s" % (f.read(), g.read())
+    with io.open("README.rst", encoding="utf-8") as f:
+        with io.open("CHANGELOG.rst", encoding="utf-8") as g:
+            return u"{}\n\n{}".format(f.read(), g.read())
 
 
 def main():
     setuptools.setup(
-        name='tox',
-        description='virtualenv-based automation of test activities',
+        name="tox",
+        description="virtualenv-based automation of test activities",
         long_description=get_long_description(),
-        url='https://tox.readthedocs.org/',
+        url="https://tox.readthedocs.org/",
         use_scm_version=True,
-        license='http://opensource.org/licenses/MIT',
-        platforms=['unix', 'linux', 'osx', 'cygwin', 'win32'],
-        author='holger krekel',
-        author_email='holger@merlinux.eu',
-        packages=['tox'],
-        entry_points={'console_scripts': ['tox=tox:cmdline',
-                                          'tox-quickstart=tox._quickstart:main']},
-        python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
-        setup_requires=['setuptools_scm'],
-        install_requires=['py>=1.4.17',
-                          'pluggy>=0.3.0,<1.0',
-                          'six',
-                          'virtualenv>=1.11.2'],
-        extras_require={'testing': ['pytest >= 3.0.0',
-                                    'pytest-cov',
-                                    'pytest-mock',
-                                    'pytest-timeout',
-                                    'pytest-xdist'],
-                        'docs': ['sphinx >= 1.6.3, < 2',
-                                 'towncrier >= 17.8.0'],
-                        'lint': ['flake8 == 3.4.1',
-                                 'flake8-bugbear == 17.4.0',
-                                 'pre-commit == 1.4.4'],
-                        'publish': ['devpi',
-                                    'twine']},
-        classifiers=['Development Status :: 5 - Production/Stable',
-                     'Framework :: tox',
-                     'Intended Audience :: Developers',
-                     'License :: OSI Approved :: MIT License',
-                     'Operating System :: POSIX',
-                     'Operating System :: Microsoft :: Windows',
-                     'Operating System :: MacOS :: MacOS X',
-                     'Topic :: Software Development :: Testing',
-                     'Topic :: Software Development :: Libraries',
-                     'Topic :: Utilities'] + [
-                        ('Programming Language :: Python :: {}'.format(x)) for
-                        x in '2 2.7 3 3.4 3.5 3.6'.split()]
+        license="http://opensource.org/licenses/MIT",
+        platforms=["unix", "linux", "osx", "cygwin", "win32"],
+        author="holger krekel",
+        author_email="holger@merlinux.eu",
+        packages=["tox"],
+        entry_points={
+            "console_scripts": ["tox=tox:cmdline", "tox-quickstart=tox._quickstart:main"]
+        },
+        python_requires=">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*",
+        setup_requires=["setuptools_scm"],
+        install_requires=["py>=1.4.17", "pluggy>=0.3.0,<1.0", "six", "virtualenv>=1.11.2"],
+        extras_require={
+            "testing": [
+                "pytest >= 3.0.0", "pytest-cov", "pytest-mock", "pytest-timeout", "pytest-xdist"
+            ],
+            "docs": ["sphinx >= 1.6.3, < 2", "towncrier >= 17.8.0"],
+            "lint": ["flake8 == 3.5.0", "flake8-bugbear == 18.2.0", "pre-commit == 1.8.2"],
+            "publish": ["devpi", "twine"],
+        },
+        classifiers=[
+            "Development Status :: 5 - Production/Stable",
+            "Framework :: tox",
+            "Intended Audience :: Developers",
+            "License :: OSI Approved :: MIT License",
+            "Operating System :: POSIX",
+            "Operating System :: Microsoft :: Windows",
+            "Operating System :: MacOS :: MacOS X",
+            "Topic :: Software Development :: Testing",
+            "Topic :: Software Development :: Libraries",
+            "Topic :: Utilities",
+        ]
+        + [
+            ("Programming Language :: Python :: {}".format(x))
+            for x in "2 2.7 3 3.4 3.5 3.6".split()
+        ],
     )
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     main()

tasks/pre-process-changelog.py

@@ -17,28 +17,28 @@ def include_draft_newsfragments():
     current_path = os.getcwd()
     try:
         os.chdir(project_root)
-        cmd = ['towncrier', '--draft', '--dir', project_root]
-        out = subprocess.check_output(cmd).decode('utf-8').strip()
-        docs_build_dir = project_root / '.tox' / 'docs' / 'fragments.rst'
+        cmd = ["towncrier", "--draft", "--dir", project_root]
+        out = subprocess.check_output(cmd).decode("utf-8").strip()
+        docs_build_dir = project_root / ".tox" / "docs" / "fragments.rst"
         docs_build_dir.write(out)
     finally:
         os.chdir(current_path)
 
 
 def manipulate_the_news():
-    home = 'https://github.com'
-    issue = '%s/issue' % home
-    fragmentsPath = Path(__file__).parents[1] / 'tox' / 'changelog'
+    home = "https://github.com"
+    issue = "{}/issue".format(home)
+    fragmentsPath = Path(__file__).parents[1] / "tox" / "changelog"
     for pattern, replacement in (
-        (r'[^`]@([^,\s]+)', r'`@\1 <%s/\1>`_' % home),
-        (r'[^`]#([\d]+)', r'`#pr\1 <%s/\1>`_' % issue),
+        (r"[^`]@([^,\s]+)", r"`@\1 <{}/\1>`_".format(home)),
+        (r"[^`]#([\d]+)", r"`#pr\1 <{}/\1>`_".format(issue)),
     ):
-        for path in fragmentsPath.glob('*.rst'):
+        for path in fragmentsPath.glob("*.rst"):
             path.write_text(re.sub(pattern, replacement, path.read_text()))
 
 
 main = manipulate_the_news
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     sys.exit(main())

tests/conftest.py

@@ -1,4 +1,5 @@
 # FIXME this seems unnecessary
 # TODO move fixtures here and only keep helper functions/classes in the plugin
 # TODO _pytest_helpers might be a better name than _pytestplugin then?
+# noinspection PyUnresolvedReferences
 from tox._pytestplugin import *  # noqa