fix: fix downscoped

Author: arithmetic1728

google/auth/downscoped.py

@@ -50,6 +50,8 @@
 
 import datetime
 
+import six
+
 from google.auth import _helpers
 from google.auth import credentials
 from google.oauth2 import sts
@@ -221,7 +223,7 @@ def available_resource(self, value):
         Raises:
             TypeError: If the value is not a string.
         """
-        if not isinstance(value, str):
+        if not isinstance(value, six.string_types):
             raise TypeError("The provided available_resource is not a string.")
         self._available_resource = value
 
@@ -247,7 +249,7 @@ def available_permissions(self, value):
             ValueError: If the value is not valid.
         """
         for available_permission in value:
-            if not isinstance(available_permission, str):
+            if not isinstance(available_permission, six.string_types):
                 raise TypeError(
                     "Provided available_permissions are not a list of strings."
                 )
@@ -350,7 +352,7 @@ def expression(self, value):
         Raises:
             TypeError: If the value is not of type string.
         """
-        if not isinstance(value, str):
+        if not isinstance(value, six.string_types):
             raise TypeError("The provided expression is not a string.")
         self._expression = value
 
@@ -373,7 +375,7 @@ def title(self, value):
         Raises:
             TypeError: If the value is not of type string or None.
         """
-        if not isinstance(value, str) and value is not None:
+        if not isinstance(value, six.string_types) and value is not None:
             raise TypeError("The provided title is not a string or None.")
         self._title = value
 
@@ -396,7 +398,7 @@ def description(self, value):
         Raises:
             TypeError: If the value is not of type string or None.
         """
-        if not isinstance(value, str) and value is not None:
+        if not isinstance(value, six.string_types) and value is not None:
             raise TypeError("The provided description is not a string or None.")
         self._description = value
 

system_tests/noxfile.py

@@ -383,9 +383,8 @@ def mtls_http(session):
 def external_accounts(session):
     session.install(
         *TEST_DEPENDENCIES_SYNC,
-        "google-auth",
+        LIBRARY_DIR,
         "google-api-python-client",
-        "enum34",
     )
     default(
         session,
@@ -394,26 +393,11 @@ def external_accounts(session):
     )
 
 
-@nox.session(python=["2.7"])
-def downscoping_27(session):
-    session.install(
-        *TEST_DEPENDENCIES_SYNC,
-        "enum34",
-        "google-auth",
-        "google-cloud-storage",
-    )
-    default(
-        session,
-        "system_tests_sync/test_downscoping.py",
-        *session.posargs,
-    )
-
-
-@nox.session(python=["3.7"])
-def downscoping_37(session):
+@nox.session(python=PYTHON_VERSIONS_SYNC)
+def downscoping(session):
     session.install(
         *TEST_DEPENDENCIES_SYNC,
-        "google-auth",
+        LIBRARY_DIR,
         "google-cloud-storage",
     )
     default(