chore: add 'blacken' stanza to noxfile

.flake8

@@ -3,7 +3,7 @@ import-order-style=google
 # Note: this forces all google imports to be in the third group. See
 # https://github.com/PyCQA/flake8-import-order/issues/111
 application-import-names=google
-ignore = E203, E266, E501, W503
+ignore = E203, E266, E501, W503, I202
 exclude =
   __pycache__,
   .git,

docs/conf.py

@@ -313,13 +313,7 @@
 # One entry per manual page. List of tuples
 # (source start file, name, description, authors, manual section).
 man_pages = [
-    (
-        master_doc,
-        "google-cloud-core",
-        u"google-cloud-core Documentation",
-        [author],
-        1,
-    )
+    (master_doc, "google-cloud-core", u"google-cloud-core Documentation", [author], 1,)
 ]
 
 # If true, show URL addresses after external links.
@@ -360,14 +354,10 @@
 intersphinx_mapping = {
     "python": ("https://python.readthedocs.org/en/latest/", None),
     "google-auth": ("https://googleapis.dev/python/google-auth/latest/", None),
-    "google.api_core": (
-        "https://googleapis.dev/python/google-api-core/latest/",
-        None,
-    ),
+    "google.api_core": ("https://googleapis.dev/python/google-api-core/latest/", None,),
     "grpc": ("https://grpc.github.io/grpc/python/", None),
     "proto-plus": ("https://proto-plus-python.readthedocs.io/en/latest/", None),
     "protobuf": ("https://googleapis.dev/python/protobuf/latest/", None),
-
 }
 
 

google/cloud/_http.py

@@ -15,9 +15,10 @@
 """Shared implementation of connections to API servers."""
 
 import collections
+
 try:
     import collections.abc as collections_abc
-except ImportError:
+except ImportError:  # Python2
     import collections as collections_abc
 import json
 import os
@@ -34,9 +35,7 @@
 API_BASE_URL = "https://www.googleapis.com"
 """The base of the API call URL."""
 
-DEFAULT_USER_AGENT = "gcloud-python/{0}".format(
-    version.__version__
-)
+DEFAULT_USER_AGENT = "gcloud-python/{0}".format(version.__version__)
 """The user agent for google-cloud-python requests."""
 
 CLIENT_INFO_HEADER = "X-Goog-API-Client"
@@ -83,14 +82,12 @@ def USER_AGENT(self):
         :rtype: str
         :returns: user agent
         """
-        warnings.warn(
-            _USER_AGENT_ALL_CAPS_DEPRECATED, DeprecationWarning, stacklevel=2)
+        warnings.warn(_USER_AGENT_ALL_CAPS_DEPRECATED, DeprecationWarning, stacklevel=2)
         return self.user_agent
 
     @USER_AGENT.setter
     def USER_AGENT(self, value):
-        warnings.warn(
-            _USER_AGENT_ALL_CAPS_DEPRECATED, DeprecationWarning, stacklevel=2)
+        warnings.warn(_USER_AGENT_ALL_CAPS_DEPRECATED, DeprecationWarning, stacklevel=2)
         self.user_agent = value
 
     @property
@@ -114,13 +111,15 @@ def _EXTRA_HEADERS(self):
         :returns: header keys / values
         """
         warnings.warn(
-            _EXTRA_HEADERS_ALL_CAPS_DEPRECATED, DeprecationWarning, stacklevel=2)
+            _EXTRA_HEADERS_ALL_CAPS_DEPRECATED, DeprecationWarning, stacklevel=2
+        )
         return self.extra_headers
 
     @_EXTRA_HEADERS.setter
     def _EXTRA_HEADERS(self, value):
         warnings.warn(
-            _EXTRA_HEADERS_ALL_CAPS_DEPRECATED, DeprecationWarning, stacklevel=2)
+            _EXTRA_HEADERS_ALL_CAPS_DEPRECATED, DeprecationWarning, stacklevel=2
+        )
         self.extra_headers = value
 
     @property
@@ -222,7 +221,9 @@ def get_api_base_url_for_mtls(self, api_base_url=None):
             url_to_use = self.API_BASE_URL
         else:
             if self.ALLOW_AUTO_SWITCH_TO_MTLS_URL:
-                url_to_use = self.API_BASE_MTLS_URL if self.http.is_mtls else self.API_BASE_URL
+                url_to_use = (
+                    self.API_BASE_MTLS_URL if self.http.is_mtls else self.API_BASE_URL
+                )
             else:
                 url_to_use = self.API_BASE_URL
         return url_to_use

google/cloud/client.py

@@ -158,9 +158,12 @@ def __init__(self, credentials=None, _http=None, client_options=None):
 
         if credentials and client_options.credentials_file:
             raise google.api_core.exceptions.DuplicateCredentialArgs(
-                "'credentials' and 'client_options.credentials_file' are mutually exclusive.")
+                "'credentials' and 'client_options.credentials_file' are mutually exclusive."
+            )
 
-        if credentials and not isinstance(credentials, google.auth.credentials.Credentials):
+        if credentials and not isinstance(
+            credentials, google.auth.credentials.Credentials
+        ):
             raise ValueError(_GOOGLE_AUTH_CREDENTIALS_HELP)
 
         scopes = client_options.scopes or self.SCOPE
@@ -169,15 +172,19 @@ def __init__(self, credentials=None, _http=None, client_options=None):
         if not _http and credentials is None:
             if client_options.credentials_file:
                 credentials, _ = google.auth.load_credentials_from_file(
-                    client_options.credentials_file, scopes=scopes)
+                    client_options.credentials_file, scopes=scopes
+                )
             else:
                 credentials, _ = google.auth.default(scopes=scopes)
 
         self._credentials = google.auth.credentials.with_scopes_if_required(
-            credentials, scopes=scopes)
+            credentials, scopes=scopes
+        )
 
         if client_options.quota_project_id:
-            self._credentials = self._credentials.with_quota_project(client_options.quota_project_id)
+            self._credentials = self._credentials.with_quota_project(
+                client_options.quota_project_id
+            )
 
         self._http_internal = _http
         self._client_cert_source = client_options.client_cert_source
@@ -202,8 +209,7 @@ def _http(self):
         """
         if self._http_internal is None:
             self._http_internal = google.auth.transport.requests.AuthorizedSession(
-                self._credentials,
-                refresh_timeout=_CREDENTIALS_REFRESH_TIMEOUT,
+                self._credentials, refresh_timeout=_CREDENTIALS_REFRESH_TIMEOUT,
             )
             self._http_internal.configure_mtls_channel(self._client_cert_source)
         return self._http_internal
@@ -233,8 +239,7 @@ def __init__(self, project=None, credentials=None):
         # https://github.com/googleapis/python-cloud-core/issues/27
         if project is None:
             project = os.getenv(
-                environment_vars.PROJECT,
-                os.getenv(environment_vars.LEGACY_PROJECT),
+                environment_vars.PROJECT, os.getenv(environment_vars.LEGACY_PROJECT),
             )
 
         # Project set on explicit credentials overrides discovery from
@@ -296,4 +301,6 @@ class ClientWithProject(Client, _ClientProjectMixin):
 
     def __init__(self, project=None, credentials=None, client_options=None, _http=None):
         _ClientProjectMixin.__init__(self, project=project, credentials=credentials)
-        Client.__init__(self, credentials=credentials, client_options=client_options, _http=_http)
+        Client.__init__(
+            self, credentials=credentials, client_options=client_options, _http=_http
+        )

noxfile.py

@@ -19,10 +19,35 @@
 import nox
 
 
+BLACK_VERSION = "black==19.10b0"
+BLACK_PATHS = ["docs", "google", "tests", "noxfile.py", "setup.py"]
+
 DEFAULT_PYTHON_VERSION = "3.7"
 CURRENT_DIRECTORY = os.path.abspath(os.path.dirname(__file__))
 
 
+@nox.session(python=DEFAULT_PYTHON_VERSION)
+def lint(session):
+    """Run linters.
+
+    Returns a failure if the linters find linting errors or sufficiently
+    serious code quality issues.
+    """
+    session.install("flake8", "flake8-import-order", BLACK_VERSION)
+    session.install(".")
+    session.run("flake8", "google", "tests")
+
+
+@nox.session(python=DEFAULT_PYTHON_VERSION)
+def blacken(session):
+    """Run black.
+
+    Format code to uniform standard.
+    """
+    session.install(BLACK_VERSION)
+    session.run("black", *BLACK_PATHS)
+
+
 def default(session):
     """Default unit test session.
     This is intended to be run **without** an interpreter set, so
@@ -51,7 +76,7 @@ def default(session):
         "--cov-report=",
         "--cov-fail-under=0",
         os.path.join("tests", "unit"),
-        *session.posargs
+        *session.posargs,
     )
 
 
@@ -61,18 +86,6 @@ def unit(session):
     default(session)
 
 
-@nox.session(python=DEFAULT_PYTHON_VERSION)
-def lint(session):
-    """Run linters.
-
-    Returns a failure if the linters find linting errors or sufficiently
-    serious code quality issues.
-    """
-    session.install("flake8", "flake8-import-order")
-    session.install(".")
-    session.run("flake8", "google", "tests")
-
-
 @nox.session(python=DEFAULT_PYTHON_VERSION)
 def lint_setup_py(session):
     """Verify that setup.py is valid (including RST check)."""

owlbot.py

@@ -35,3 +35,5 @@
         "setup.cfg",
     ],
 )
+
+s.shell.run(["nox", "-s", "blacken"], hide_output=False)

tests/unit/test__http.py

@@ -186,14 +186,18 @@ def test_build_api_url_no_extra_query_params(self):
         client = object()
         conn = self._make_mock_one(client)
         # Intended to emulate self.mock_template
-        URI = "/".join([conn.API_BASE_URL, "mock", conn.API_VERSION, "foo?prettyPrint=false"])
+        URI = "/".join(
+            [conn.API_BASE_URL, "mock", conn.API_VERSION, "foo?prettyPrint=false"]
+        )
         self.assertEqual(conn.build_api_url("/foo"), URI)
 
     def test_build_api_url_w_pretty_print_query_params(self):
         client = object()
         conn = self._make_mock_one(client)
         uri = conn.build_api_url("/foo", {"prettyPrint": "true"})
-        URI = "/".join([conn.API_BASE_URL, "mock", conn.API_VERSION, "foo?prettyPrint=true"])
+        URI = "/".join(
+            [conn.API_BASE_URL, "mock", conn.API_VERSION, "foo?prettyPrint=true"]
+        )
         self.assertEqual(uri, URI)
 
     def test_build_api_url_w_extra_query_params(self):
@@ -220,7 +224,9 @@ def test_build_api_url_w_extra_query_params_tuples(self):
 
         client = object()
         conn = self._make_mock_one(client)
-        uri = conn.build_api_url("/foo", [("bar", "baz"), ("qux", "quux"), ("qux", "corge")])
+        uri = conn.build_api_url(
+            "/foo", [("bar", "baz"), ("qux", "quux"), ("qux", "corge")]
+        )
 
         scheme, netloc, path, qs, _ = urlsplit(uri)
         self.assertEqual("%s://%s" % (scheme, netloc), conn.API_BASE_URL)