Type hint (GoogleCloudPlatform#4949)

* add details about type hinting to authoring guide

* update noxfile manually, update example config

* add enforce_type_hints to default config

Author: leahecole

noxfile-template.py

@@ -39,6 +39,10 @@
     # You can opt out from the test for specific Python versions.
     'ignored_versions': ["2.7"],
 
+    # Old samples are opted out of enforcing Python type hints
+    # All new samples should feature them
+    'enforce_type_hints': False,
+
     # An envvar key for determining the project id to use. Change it
     # to 'BUILD_SPECIFIC_GCLOUD_PROJECT' if you want to opt in using a
     # build specific Cloud project. You can also use your own string
@@ -133,7 +137,10 @@ def _determine_local_import_names(start_dir):
 
 @nox.session
 def lint(session):
-    session.install("flake8", "flake8-import-order")
+    if not TEST_CONFIG['enforce_type_hints']:
+        session.install("flake8", "flake8-import-order")
+    else:
+        session.install("flake8", "flake8-import-order", "flake8-annotations")
 
     local_names = _determine_local_import_names(".")
     args = FLAKE8_COMMON_ARGS + [

noxfile_config.py

@@ -23,6 +23,9 @@
 TEST_CONFIG_OVERRIDE = {
     # You can opt out from the test for specific Python versions.
     'ignored_versions': ["2.7"],
+    # Old samples are opted out of enforcing Python type hints
+    # All new samples should feature them
+    'enforce_type_hints': False,
 
     # An envvar key for determining the project id to use. Change it
     # to 'BUILD_SPECIFIC_GCLOUD_PROJECT' if you want to opt in using a