Fix "AttributeError: 'str' object has no attribute 'get'"

[weineran]

• This is a bug fix.
• The current code assumes that response_data will always be a dict or a mapping of some kind, but it is possible for response_data to be a str.
• When response_data is a str, then the function fails on response_data.get("error") but the error response is swallowed so the user doesn't know why it failed. The user just sees: AttributeError: 'str' object has no attribute 'get' and a stacktrace
• This is a quick and dirty fix that guarantees the .get call will succeed, and the result is that the error response bubbles up to the user.
• Feel free to make this fix more robust/clean.

Steps to reproduce the bug

• Set credentials like this:

credentials = google.oauth2.credentials.Credentials(
        token=None,
        refresh_token=os.getenv('GCP_REFRESH_TOKEN'),
        token_uri=os.getenv('GCP_TOKEN_URI'),
        client_id=os.getenv('GCP_CLIENT_ID'),
        client_secret=os.getenv('GCP_CLIENT_SECRET'))

But ensure that there is a typo in GCP_TOKEN_URI. Example: "https://oauth2.googleapis.com/token1"

• Use the credentials to authenticate. Example:

df.to_gbq(destination_table=tablename, project_id=project_id, if_exists=if_exists, table_schema=schema, credentials=credentials)

Expected: Authentication should fail with a useful error response
Actual: Authentication fails with an AttributeError: "AttributeError: 'str' object has no attribute 'get'"

[clundin25]

Thanks for fixing this. This was fixed in the oauth2 client code like so.

Suggested change

	if type(response_data) != dict:
	response_data = {"data": response_data}
	if isinstance(response_data, six.string_types):
	raise exceptions.RefreshError(response_data, retryable=False)

Please make sure to add a unit test for this!

[weineran]

Hey @clundin25, I'm not really interested in running with this one. Mostly just wanted to point out the bug.

If the maintainers want to take over from here, that would be great 😊

[arithmetic1728]

fixed in #1316 @weineran thank you for pointing out the issue and for your fix!

[weineran]

Awesome!