Add style checker and formatter (#3299)

.flake8

@@ -0,0 +1,7 @@
+# TODO: port this to pyproject.toml when supported: https://gitlab.com/pycqa/flake8/merge_requests/245
+
+[flake8]
+select = B,C,E,F,W,B001,B003,B006,B007,B301,B305,B306,B902
+ignore = E203,E722,W503
+exclude = .eggs,.tox,build,compat.py,__init__.py,datadog_checks/dev/tooling/templates/*,datadog_checks/*/vendor/*
+max-line-length = 120

datadog_checks_dev/datadog_checks/dev/plugin/plugin.py → datadog_checks_dev/datadog_checks/dev/plugin/pytest.py

@@ -1,6 +1,8 @@
 # (C) Datadog, Inc. 2018
 # All rights reserved
 # Licensed under a 3-clause BSD style license (see LICENSE)
+from __future__ import absolute_import
+
 import json
 import os
 from base64 import urlsafe_b64encode

datadog_checks_dev/datadog_checks/dev/plugin/tox.py

@@ -0,0 +1,104 @@
+# (C) Datadog, Inc. 2019
+# All rights reserved
+# Licensed under a 3-clause BSD style license (see LICENSE)
+from __future__ import absolute_import
+
+import tox
+import tox.config
+
+STYLE_CHECK_ENV_NAME = 'style'
+STYLE_FORMATTER_ENV_NAME = 'format_style'
+STYLE_FLAG = 'dd_check_style'
+
+
+@tox.hookimpl
+def tox_configure(config):
+    """
+    For more info, see: https://tox.readthedocs.io/en/latest/plugins.html
+    For an example, see: https://github.com/tox-dev/tox-travis
+    """
+    sections = config._cfg.sections
+
+    # Cache these
+    make_envconfig = None
+    reader = None
+
+    # Default to false so:
+    # 1. we don't affect other projects using tox
+    # 2. check migrations can happen gradually
+    if str(sections.get('testenv', {}).get(STYLE_FLAG, 'false')).lower() == 'true':
+        # Disable flake8 since we already include that
+        config.envlist[:] = [env for env in config.envlist if not env.endswith('flake8')]
+
+        make_envconfig = get_make_envconfig(make_envconfig)
+        reader = get_reader(reader, config)
+
+        add_style_checker(config, sections, make_envconfig, reader)
+        add_style_formatter(config, sections, make_envconfig, reader)
+
+
+def add_style_checker(config, sections, make_envconfig, reader):
+    # testenv:style
+    section = '{}{}'.format(tox.config.testenvprefix, STYLE_CHECK_ENV_NAME)
+    sections[section] = {
+        # These tools only support Python 3+
+        'basepython': 'python3',
+        'skip_install': 'true',
+        'deps': 'flake8\nflake8-bugbear\nblack\nisort[pyproject]>=4.3.15',
+        'commands': 'flake8 --config=../.flake8 .\nblack --check --diff .\nisort --check-only --diff --recursive .',
+    }
+
+    # Always add the environment configurations
+    config.envconfigs[STYLE_CHECK_ENV_NAME] = make_envconfig(
+        config, STYLE_CHECK_ENV_NAME, section, reader._subs, config
+    )
+
+    # Intentionally add to envlist when seeing what is available
+    if any('--listenvs' in arg for arg in config.args):
+        config.envlist.append(STYLE_CHECK_ENV_NAME)
+
+
+def add_style_formatter(config, sections, make_envconfig, reader):
+    # testenv:format_style
+    section = '{}{}'.format(tox.config.testenvprefix, STYLE_FORMATTER_ENV_NAME)
+    sections[section] = {
+        # These tools only support Python 3+
+        'basepython': 'python3',
+        'skip_install': 'true',
+        'deps': 'black\nisort[pyproject]>=4.3.15',
+        # Run formatter AFTER sorting imports
+        'commands': 'isort --recursive .\nblack .',
+    }
+
+    # Always add the environment configurations
+    config.envconfigs[STYLE_FORMATTER_ENV_NAME] = make_envconfig(
+        config, STYLE_FORMATTER_ENV_NAME, section, reader._subs, config
+    )
+
+    # Intentionally add to envlist when seeing what is available
+    if any('--listenvs' in arg for arg in config.args):
+        config.envlist.append(STYLE_FORMATTER_ENV_NAME)
+
+
+def get_make_envconfig(make_envconfig):
+    if make_envconfig is None:
+        make_envconfig = tox.config.ParseIni.make_envconfig
+
+        # Make this a non-bound method for Python 2 compatibility
+        make_envconfig = getattr(make_envconfig, '__func__', make_envconfig)
+
+    return make_envconfig
+
+
+def get_reader(reader, config):
+    if reader is None:
+        # This is just boilerplate necessary to create a valid reader
+        reader = tox.config.SectionReader('tox', config._cfg)
+        reader.addsubstitutions(toxinidir=config.toxinidir, homedir=config.homedir)
+        reader.addsubstitutions(toxworkdir=config.toxworkdir)
+        config.distdir = reader.getpath('distdir', '{toxworkdir}/dist')
+        reader.addsubstitutions(distdir=config.distdir)
+        config.distshare = reader.getpath('distshare', '{homedir}/.tox/distshare')
+        reader.addsubstitutions(distshare=config.distshare)
+
+    return reader

datadog_checks_dev/datadog_checks/dev/tooling/commands/test.py

@@ -5,7 +5,7 @@
 
 import click
 
-from .console import CONTEXT_SETTINGS, abort, echo_info, echo_success, echo_waiting
+from .console import CONTEXT_SETTINGS, abort, echo_info, echo_success, echo_waiting, echo_warning
 from ..constants import get_root
 from ..testing import construct_pytest_options, fix_coverage_report, get_tox_envs, pytest_coverage_sources
 from ...subprocess import run_command
@@ -24,6 +24,7 @@ def display_envs(check_envs):
     short_help='Run tests'
 )
 @click.argument('checks', nargs=-1)
+@click.option('--format-style', '-fs', is_flag=True, help='Run only the code style formatter')
 @click.option('--style', '-s', is_flag=True, help='Run only style checks')
 @click.option('--bench', '-b', is_flag=True, help='Run only benchmarks')
 @click.option('--cov', '-c', 'coverage', is_flag=True, help='Measure code coverage')
@@ -38,6 +39,7 @@ def display_envs(check_envs):
 @click.option('--cov-keep', is_flag=True, help='Keep coverage reports')
 def test(
     checks,
+    format_style,
     style,
     bench,
     coverage,
@@ -98,11 +100,11 @@ def test(
         'PYTEST_ADDOPTS': pytest_options,
     }
 
-    check_envs = get_tox_envs(checks, style=style, benchmark=bench, changed_only=changed)
+    check_envs = get_tox_envs(checks, style=style, format_style=format_style, benchmark=bench, changed_only=changed)
     tests_ran = False
 
     for check, envs in check_envs:
-        # Many check don't have benchmark envs, etc.
+        # Many checks don't have benchmark envs, etc.
         if not envs:
             continue
 
@@ -121,7 +123,9 @@ def test(
             echo_info('pytest options: `{}`'.format(test_env_vars['PYTEST_ADDOPTS']))
 
         with chdir(os.path.join(root, check), env_vars=test_env_vars):
-            if style:
+            if format_style:
+                test_type_display = 'the code formatter'
+            elif style:
                 test_type_display = 'only style checks'
             elif bench:
                 test_type_display = 'only benchmarks'
@@ -173,4 +177,8 @@ def test(
         echo_success('\nPassed!')
 
     if not tests_ran:
-        echo_info('Nothing to test!')
+        if format_style:
+            echo_warning('Code formatting is not enabled!')
+            echo_info('To enabled it, put `dd_check_style = true` under the `[testenv]` section of `tox.ini`.')
+        else:
+            echo_info('Nothing to test!')

datadog_checks_dev/datadog_checks/dev/tooling/templates/check/{check_name}/datadog_checks/{check_name}/__init__.py

@@ -1,7 +1,4 @@
 {license_header}from .__about__ import __version__
 from .{check_name} import {check_class}
 
-__all__ = [
-    '__version__',
-    '{check_class}'
-]
+__all__ = ['__version__', '{check_class}']

datadog_checks_dev/datadog_checks/dev/tooling/templates/check/{check_name}/setup.py

@@ -25,17 +25,13 @@
     long_description=long_description,
     long_description_content_type='text/markdown',
     keywords='datadog agent {check_name} check',
-
     # The project's main homepage.
     url='https://github.com/DataDog/integrations-{repo_choice}',
-
     # Author details
     author='{author}',
     author_email='{email_packages}',
-
     # License
     license='BSD-3-Clause',
-
     # See https://pypi.org/classifiers
     classifiers=[
         'Development Status :: 5 - Production/Stable',
@@ -47,13 +43,10 @@
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
     ],
-
     # The package we're going to ship
     packages=['datadog_checks.{check_name}'],
-
     # Run-time dependencies
     install_requires=[CHECKS_BASE_REQ],
-
     # Extra files to ship with the wheel package
     include_package_data=True,
 )

datadog_checks_dev/datadog_checks/dev/tooling/templates/check/{check_name}/tox.ini

@@ -7,6 +7,7 @@ envlist =
     flake8
 
 [testenv]
+dd_check_style = true
 usedevelop = true
 platform = linux|darwin|win32
 deps =

datadog_checks_dev/datadog_checks/dev/tooling/testing.py

@@ -7,12 +7,11 @@
 from ..subprocess import run_command
 from ..utils import chdir, path_join, read_file_binary, write_file_binary
 
-STYLE_ENVS = {
-    'flake8',
-}
+STYLE_CHECK_ENVS = {'flake8', 'style'}
+STYLE_ENVS = {'flake8', 'style', 'format_style'}
 
 
-def get_tox_envs(checks, style=False, benchmark=False, every=False, changed_only=False, sort=False):
+def get_tox_envs(checks, style=False, format_style=False, benchmark=False, every=False, changed_only=False, sort=False):
     testable_checks = get_testable_checks()
     # Run `get_changed_checks` at most once because git calls are costly
     changed_checks = get_changed_checks() if not checks or changed_only else None
@@ -36,10 +35,15 @@ def get_tox_envs(checks, style=False, benchmark=False, every=False, changed_only
         envs_selected = envs_selected.split(',') if envs_selected else []
         envs_available = get_available_tox_envs(check, sort=sort)
 
-        if style:
+        if format_style:
             envs_selected[:] = [
                 e for e in envs_available
-                if e in STYLE_ENVS
+                if 'format_style' in e
+            ]
+        elif style:
+            envs_selected[:] = [
+                e for e in envs_available
+                if e in STYLE_CHECK_ENVS
             ]
         elif benchmark:
             envs_selected[:] = [
@@ -64,7 +68,7 @@ def get_tox_envs(checks, style=False, benchmark=False, every=False, changed_only
             else:
                 envs_selected[:] = [
                     e for e in envs_available
-                    if 'bench' not in e
+                    if 'bench' not in e and 'format_style' not in e
                 ]
 
         yield check, envs_selected

datadog_checks_dev/setup.py

@@ -83,14 +83,15 @@
             'semver',
             'setuptools>=38.6.0',
             'toml>=0.9.4, <1.0.0',
-            'tox',
+            'tox>=3.7.0',
             'twine>=1.11.0',
             'wheel>=0.31.0',
         ],
     },
 
     entry_points={
-        'pytest11': ['datadog_checks = datadog_checks.dev.plugin.plugin'],
+        'pytest11': ['datadog_checks = datadog_checks.dev.plugin.pytest'],
+        'tox': ['datadog_checks = datadog_checks.dev.plugin.tox'],
         'console_scripts': [
             'ddev = datadog_checks.dev.tooling.cli:ddev',
         ],

pyproject.toml

@@ -1,3 +1,46 @@
+# NOTE: You have to use single-quoted strings in TOML for regular expressions.
+# It's the equivalent of r-strings in Python. Multiline strings are treated as
+# verbose regular expressions by Black. Use [ ] to denote a significant space
+# character.
+
 [tool.black]
+exclude = '''
+# Directories
+/(
+    \.eggs
+  | \.git
+  | \.hg
+  | \.mypy_cache
+  | \.tox
+  | \.venv
+  | _build
+  | buck-out
+  | build
+  | dist
+
+  # New integration templates
+  | datadog_checks/dev/tooling/templates
+  # Vendored third party libraries
+  | datadog_checks/[^/]+/vendor
+)/
+  |
+# Files
+(
+    # TODO: remove when upstream addresses https://github.com/DataDog/integrations-core/blob/c71e6d7204192a8002109da92452003598df2d28/datadog_checks_dev/datadog_checks/dev/tooling/signing.py#L9-L14
+    datadog_checks/dev/tooling/signing\.py$
+)
+'''
+include = '\.pyi?$'
 line-length = 120
+py36 = false
 skip-string-normalization = true
+
+[tool.isort]
+default_section = 'THIRDPARTY'
+force_grid_wrap = 0
+include_trailing_comma = true
+known_first_party = 'datadog_checks'
+line_length = 120
+multi_line_output = 3
+skip_glob = 'datadog_checks/dev/tooling/signing.py,datadog_checks/dev/tooling/templates/*,datadog_checks/*/vendor/*'
+use_parentheses = true