Add the rest of TurfHelper test

[cammace]

The TurfHelper class currently doesn't have any test, #481 adds the test class and a single method test but the rest are missing.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically detected as stale because it has not had recent activity and will be archived. Thank you for your contributions.