turn character vectors into factors

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 97.34%. Comparing base (f2c3c22) to head (47bc6ac). Report is 2 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #54 +/- ## ========================================== + Coverage 97.23% 97.34% +0.11% ========================================== Files 17 17 Lines 1701 1735 +34 ========================================== + Hits 1654 1689 +35 + Misses 47 46 -1 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[sbfnk]

macos failure is unrelated