Blackify some files to show style differences

.gitignore

@@ -245,6 +245,7 @@ wheels/
 *.egg-info/
 .installed.cfg
 *.egg
+pip-wheel-metadata/
 
 # PyInstaller
 #  Usually these files are written by a python script from a template

.pre-commit-config.yaml

@@ -0,0 +1,7 @@
+repos:
+  - repo: https://github.com/python/black
+    rev: 19.3b0
+    hooks:
+      - id: black
+        language_version: python3.7
+        exclude_types: ['markdown', 'ini', 'toml']

DEVELOPMENT_GUIDE.md

@@ -36,7 +36,20 @@ easily setup multiple Python versions.
 5.  Make Python versions available in the project:
     `pyenv local 3.6.8 2.7.14 3.7.2`
 
-### 2. Activate Virtualenv
+### 2. Install Additional Tooling
+#### Black
+We format our code using [Black](https://github.com/python/black) and verify the source code is black compliant
+in Appveyor during PRs. You can find installation instructions on [Black's docs](https://black.readthedocs.io/en/stable/installation_and_usage.html).
+
+After installing, you can run our formatting through our Makefile by `make black-format` or integrating Black directly in your favorite IDE (instructions
+can be found [here](https://black.readthedocs.io/en/stable/editor_integration.html))
+
+#### Pre-commit
+If you don't wish to manually run black on each pr or install black manually, we have integrated black into git hooks through [pre-commit](https://pre-commit.com/).
+After installing pre-commit, run `pre-commit install` in the root of the project. This will install black for you and run the black formatting on
+commit.
+
+### 3. Activate Virtualenv
 
 Virtualenv allows you to install required libraries outside of the
 Python installation. A good practice is to setup a different virtualenv
@@ -49,7 +62,7 @@ be the appropriate python version.
 1.  `pyenv virtualenv 3.7.2 samcli37`
 2.  `pyenv activate samcli37` for Python3.7
 
-### 3. Install dev version of SAM CLI
+### 4. Install dev version of SAM CLI
 
 We will install a development version of SAM CLI from source into the
 virtualenv for you to try out the CLI as you make changes. We will
@@ -60,7 +73,7 @@ SAM CLI installation, if any.
 2.  Install dev CLI: `make init`
 3.  Make sure installation succeeded: `which samdev`
 
-### 4. (Optional) Install development version of SAM Transformer
+### 5. (Optional) Install development version of SAM Transformer
 
 If you want to run the latest version of [SAM
 Transformer](https://github.com/awslabs/serverless-application-model/),

Makefile

@@ -24,17 +24,15 @@ smoke-test:
 	# Smoke tests run in parallel
 	pytest -n 4 tests/functional
 
-flake:
-	# Make sure code conforms to PEP8 standards
-	flake8 samcli
-	flake8 tests/unit tests/integration
-
 lint:
 	# Linter performs static analysis to catch latent bugs
 	pylint --rcfile .pylintrc samcli
 
 # Command to run everytime you make changes to verify everything works
-dev: flake lint test
+dev: lint test
+
+black:
+	black samcli/* tests/*
 
 # Verifications to run before sending a pull request
-pr: init dev
+pr: init dev

appveyor.yml

@@ -56,6 +56,11 @@ for:
       - sh: "sudo unzip -d /opt/gradle /tmp/gradle-*.zip"
       - sh: "PATH=/opt/gradle/gradle-5.5/bin:$PATH"
 
+      # Install black
+      - sh: "wget -O /tmp/black https://github.com/python/black/releases/download/19.3b0/black"
+      - sh: "chmod +x /tmp/black"
+      - sh: "/tmp/black --version"
+
   - 
     matrix:
       only:
@@ -72,12 +77,11 @@ build_script:
 
 test_script:
     - "pytest --cov samcli --cov-report term-missing --cov-fail-under 95 tests/unit"
-    - "flake8 samcli"
-    - "flake8 tests/unit tests/integration"
     - "pylint --rcfile .pylintrc samcli"
 
     # Runs only in Linux
     - sh: "pytest -vv tests/integration"
+    - sh: "/tmp/black --check setup.py tests samcli"
 
     # Smoke tests run in parallel - it runs on both Linux & Windows
     # Presence of the RUN_SMOKE envvar will run the smoke tests

pyproject.toml

@@ -0,0 +1,22 @@
+[build-system]
+requires = ["setuptools", "wheel"]  # PEP 508 specifications.
+
+
+[tool.black]
+line-length = 120
+target_version = ['py37', 'py27', 'py36']
+exclude = '''
+
+(
+  /(
+      \.eggs         # exclude a few common directories in the
+    | \.git          # root of the project
+    | \.tox
+    | \.venv
+    | build
+    | dist
+    | pip-wheel-metadata
+    | samcli/local/init/templates
+  )/
+)
+'''

requirements/dev.txt

@@ -1,5 +1,4 @@
 coverage==4.3.4
-flake8==3.3.0
 tox==2.2.1
 pytest-cov==2.4.0
 # astroid > 2.0.4 is not compatible with pylint1.7

samcli/__init__.py

@@ -2,4 +2,4 @@
 SAM CLI version
 """
 
-__version__ = '0.21.0'
+__version__ = "0.21.0"

samcli/cli/command.py

@@ -21,7 +21,7 @@
     "samcli.commands.package",
     "samcli.commands.deploy",
     "samcli.commands.logs",
-    "samcli.commands.publish"
+    "samcli.commands.publish",
 ]
 
 DEPRECATION_NOTICE = (
@@ -85,7 +85,7 @@ def _set_commands(package_names):
         commands = OrderedDict()
 
         for pkg_name in package_names:
-            cmd_name = pkg_name.split('.')[-1]
+            cmd_name = pkg_name.split(".")[-1]
             commands[cmd_name] = pkg_name
 
         return commands

samcli/cli/context.py

@@ -45,8 +45,8 @@ def debug(self, value):
 
         if self._debug:
             # Turn on debug logging
-            logging.getLogger('samcli').setLevel(logging.DEBUG)
-            logging.getLogger('aws_lambda_builders').setLevel(logging.DEBUG)
+            logging.getLogger("samcli").setLevel(logging.DEBUG)
+            logging.getLogger("aws_lambda_builders").setLevel(logging.DEBUG)
 
     @property
     def region(self):
@@ -135,5 +135,4 @@ def _refresh_session(self):
         the Boto3's session object are read-only. Therefore when Click parses new AWS session related properties (like
         region & profile), it will call this method to create a new session with latest values for these properties.
         """
-        boto3.setup_default_session(region_name=self._aws_region,
-                                    profile_name=self._aws_profile)
+        boto3.setup_default_session(region_name=self._aws_region, profile_name=self._aws_profile)

samcli/cli/global_config.py

@@ -46,7 +46,7 @@ def config_dir(self):
         if not self._config_dir:
             # Internal Environment variable to customize SAM CLI App Dir. Currently used only by integ tests.
             app_dir = os.getenv("__SAM_CLI_APP_DIR")
-            self._config_dir = Path(app_dir) if app_dir else Path(click.get_app_dir('AWS SAM', force_posix=True))
+            self._config_dir = Path(app_dir) if app_dir else Path(click.get_app_dir("AWS SAM", force_posix=True))
         return Path(self._config_dir)
 
     @property
@@ -106,7 +106,7 @@ def telemetry_enabled(self):
         # If environment variable is set, its value takes precedence over the value from config file.
         env_name = "SAM_CLI_TELEMETRY"
         if env_name in os.environ:
-            return os.getenv(env_name) in ('1', 1)
+            return os.getenv(env_name) in ("1", 1)
 
         try:
             self._telemetry_enabled = self._get_value(TELEMETRY_ENABLED_KEY)
@@ -200,7 +200,7 @@ def _set_json_cfg(self, filepath, key, value, json_body=None):
         json_body[key] = value
         file_body = json.dumps(json_body, indent=4) + "\n"
         try:
-            with open(str(filepath), 'w') as f:
+            with open(str(filepath), "w") as f:
                 f.write(file_body)
         except IOError as ex:
             LOG.debug("Error writing to {filepath}", exc_info=ex)

samcli/cli/main.py

@@ -15,7 +15,7 @@
 from .global_config import GlobalConfig
 
 LOG = logging.getLogger(__name__)
-logging.basicConfig(level=logging.INFO, format='%(asctime)s %(message)s', datefmt='%Y-%m-%d %H:%M:%S')
+logging.basicConfig(level=logging.INFO, format="%(asctime)s %(message)s", datefmt="%Y-%m-%d %H:%M:%S")
 
 
 pass_context = click.make_pass_decorator(Context)
@@ -47,9 +47,7 @@ def print_info(ctx, param, value):
     if not value or ctx.resilient_parsing:
         return
 
-    click.echo(json.dumps({
-        "version": __version__
-    }, indent=2))
+    click.echo(json.dumps({"version": __version__}, indent=2))
 
     ctx.exit()
 
@@ -96,9 +94,9 @@ def cli(ctx):
         except (IOError, ValueError) as ex:
             LOG.debug("Unable to write telemetry flag", exc_info=ex)
 
-    sam_cli_logger = logging.getLogger('samcli')
-    sam_cli_formatter = logging.Formatter('%(message)s')
-    lambda_builders_logger = logging.getLogger('aws_lambda_builders')
+    sam_cli_logger = logging.getLogger("samcli")
+    sam_cli_formatter = logging.Formatter("%(message)s")
+    lambda_builders_logger = logging.getLogger("aws_lambda_builders")
 
     SamCliLogger.configure_logger(sam_cli_logger, sam_cli_formatter, logging.INFO)
     SamCliLogger.configure_logger(lambda_builders_logger, sam_cli_formatter, logging.INFO)

samcli/cli/options.py

@@ -14,17 +14,20 @@ def debug_option(f):
 
     :param f: Callback Function to be passed to Click
     """
+
     def callback(ctx, param, value):
         state = ctx.ensure_object(Context)
         state.debug = value
         return value
 
-    return click.option('--debug',
-                        expose_value=False,
-                        is_flag=True,
-                        envvar="SAM_DEBUG",
-                        help='Turn on debug logging to print debug message generated by SAM CLI.',
-                        callback=callback)(f)
+    return click.option(
+        "--debug",
+        expose_value=False,
+        is_flag=True,
+        envvar="SAM_DEBUG",
+        help="Turn on debug logging to print debug message generated by SAM CLI.",
+        callback=callback,
+    )(f)
 
 
 def region_option(f):
@@ -33,15 +36,15 @@ def region_option(f):
 
     :param f: Callback Function to be passed to Click
     """
+
     def callback(ctx, param, value):
         state = ctx.ensure_object(Context)
         state.region = value
         return value
 
-    return click.option('--region',
-                        expose_value=False,
-                        help='Set the AWS Region of the service (e.g. us-east-1).',
-                        callback=callback)(f)
+    return click.option(
+        "--region", expose_value=False, help="Set the AWS Region of the service (e.g. us-east-1).", callback=callback
+    )(f)
 
 
 def profile_option(f):
@@ -50,12 +53,15 @@ def profile_option(f):
 
     :param f: Callback Function to be passed to Click
     """
+
     def callback(ctx, param, value):
         state = ctx.ensure_object(Context)
         state.profile = value
         return value
 
-    return click.option('--profile',
-                        expose_value=False,
-                        help='Select a specific profile from your credential file to get AWS credentials.',
-                        callback=callback)(f)
+    return click.option(
+        "--profile",
+        expose_value=False,
+        help="Select a specific profile from your credential file to get AWS credentials.",
+        callback=callback,
+    )(f)

samcli/cli/types.py

@@ -15,9 +15,9 @@ class CfnParameterOverridesType(click.ParamType):
     __EXAMPLE = "ParameterKey=KeyPairName,ParameterValue=MyKey ParameterKey=InstanceType,ParameterValue=t1.micro"
 
     # Regex that parses CloudFormation parameter key-value pairs: https://regex101.com/r/xqfSjW/2
-    _pattern = r'(?:ParameterKey=([A-Za-z0-9\"]+),ParameterValue=(\"(?:\\.|[^\"\\]+)*\"|(?:\\.|[^ \"\\]+)+))'
+    _pattern = r"(?:ParameterKey=([A-Za-z0-9\"]+),ParameterValue=(\"(?:\\.|[^\"\\]+)*\"|(?:\\.|[^ \"\\]+)+))"
 
-    name = ''
+    name = ""
 
     def convert(self, value, param, ctx):
         result = {}
@@ -27,9 +27,7 @@ def convert(self, value, param, ctx):
         groups = re.findall(self._pattern, value)
         if not groups:
             return self.fail(
-                "{} is not in valid format. It must look something like '{}'".format(value, self.__EXAMPLE),
-                param,
-                ctx
+                "{} is not in valid format. It must look something like '{}'".format(value, self.__EXAMPLE), param, ctx
             )
 
         # 'groups' variable is a list of tuples ex: [(key1, value1), (key2, value2)]