Fix a test failure (mismatched error strings).

Author: craigcitro

oauth2client/client.py

@@ -76,6 +76,16 @@
 # Application Default Credentials.
 GOOGLE_APPLICATION_CREDENTIALS = 'GOOGLE_APPLICATION_CREDENTIALS'
 
+# The error message we show users when we can't find the Application
+# Default Credentials.
+ADC_HELP_MSG = (
+    'The Application Default Credentials are not available. They are available '
+    'if running in Google Compute Engine. Otherwise, the environment variable '
+    + GOOGLE_APPLICATION_CREDENTIALS +
+    ' must be defined pointing to a file defining the credentials. See '
+    'https://developers.google.com/accounts/docs/application-default-credentials'  # pylint:disable=line-too-long
+    ' for more information.')
+
 # The access token along with the seconds in which it expires.
 AccessTokenInfo = collections.namedtuple(
     'AccessTokenInfo', ['access_token', 'expires_in'])
@@ -1052,13 +1062,7 @@ def get_application_default():
     elif env_name == 'GCE_PRODUCTION':
       return _get_application_default_credential_GCE()
     else:
-      raise ApplicationDefaultCredentialsError(
-          'The Application Default Credentials are not available. They are '
-          'available if running in Google Compute Engine. Otherwise, the '
-          ' environment variable ' + GOOGLE_APPLICATION_CREDENTIALS +
-          ' must be defined pointing to a file defining the credentials. '
-          'See https://developers.google.com/accounts/docs/application-default-'
-          'credentials for more information.')
+      raise ApplicationDefaultCredentialsError(ADC_HELP_MSG)
 
   @staticmethod
   def from_stream(credential_filename):

tests/test_oauth2client.py

@@ -38,6 +38,7 @@
 from oauth2client.client import AccessTokenCredentials
 from oauth2client.client import AccessTokenCredentialsError
 from oauth2client.client import AccessTokenRefreshError
+from oauth2client.client import ADC_HELP_MSG
 from oauth2client.client import AssertionCredentials
 from oauth2client.client import AUTHORIZED_USER
 from oauth2client.client import Credentials
@@ -421,14 +422,7 @@ def test_get_application_default_environment_not_set_up(self):
       GoogleCredentials.get_application_default()
       self.fail('An exception was expected!')
     except ApplicationDefaultCredentialsError as error:
-      self.assertEqual(
-          "The Application Default Credentials are not available. They are "
-          "available if running in Google Compute Engine.  Otherwise, the "
-          " environment variable " + GOOGLE_APPLICATION_CREDENTIALS +
-          " must be defined pointing to a file defining the credentials. "
-          "See https://developers.google.com/accounts/docs/application-default-"
-          "credentials for more information.",
-          str(error))
+      self.assertEqual(ADC_HELP_MSG, str(error))
 
   def test_from_stream_service_account(self):
     credentials_file = datafile(