* Fix non-sensical error message
Introduced in 12de92cd2b / #7698
* Add a test
* Put the unit back into unittest
* [pre-commit.ci] auto fixes from pre-commit.com hooks
for more information, see https://pre-commit.ci
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>