feat: accept TableListItem where TableReference is accepted

[steffnay]

Thank you for opening a Pull Request! Before submitting your PR, there are a few things you can do to make sure it goes smoothly:

• Make sure to open an issue as a bug/issue before writing your code! That way we can discuss the change, evaluate designs, and agree on the general idea
• Ensure the tests and linter pass
• Code coverage does not decrease (if any source code was changed)
• Appropriate docs were updated (if necessary)

🦕

[tswast]

Looks like we need to either update the test_get_iam_policy_w_invalid_table test to look for ValueError or update _parse_3_part_id to raise TypeError.

Based on https://docs.python.org/3/library/exceptions.html#TypeError, I think ValueError is more accurate.

________________ TestClient.test_get_iam_policy_w_invalid_table ________________
self = <tests.unit.test_client.TestClient testMethod=test_get_iam_policy_w_invalid_table>
def test_get_iam_policy_w_invalid_table(self):
creds = _make_credentials()
http = object()
client = self._make_one(project=self.PROJECT, credentials=creds, _http=http)
table_resource_string = "projects/{}/datasets/{}/tables/{}".format(
self.PROJECT, self.DS_ID, self.TABLE_ID,
)
with self.assertRaises(TypeError):
> client.get_iam_policy(table_resource_string)
tests/unit/test_client.py:1558:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
google/cloud/bigquery/client.py:813: in get_iam_policy
table = _table_arg_to_table_ref(table, default_project=self.project)
google/cloud/bigquery/table.py:2666: in _table_arg_to_table_ref
value = TableReference.from_string(value, default_project=default_project)
google/cloud/bigquery/table.py:252: in from_string
) = _helpers._parse_3_part_id(
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
def _parse_3_part_id(full_id, default_project=None, property_name="table_id"):
output_project_id = default_project
output_dataset_id = None
output_resource_id = None
parts = _split_id(full_id)
if len(parts) != 2 and len(parts) != 3:
> raise ValueError(
"{property_name} must be a fully-qualified ID in "
'standard SQL format, e.g., "project.dataset.{property_name}", '
"got {}".format(full_id, property_name=property_name)
)
E ValueError: table_id must be a fully-qualified ID in standard SQL format, e.g., "project.dataset.table_id", got projects/PROJECT/datasets/DATASET_ID/tables/TABLE_ID
google/cloud/bigquery/_helpers.py:848: ValueError

[tswast]

Need unit test that covers this. Possibly this if statement can be deleted if _table_arg_to_table_ref already throws?

[tswast]

Line not covered in unit tests

[steffnay]

Ah, got it! Thanks!

[tswast]

Line not covered in unit tests