Tidy pass_names_to_solver and add tests

[codecov[bot]]

Codecov Report

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

Project coverage is 68.05%. Comparing base (4bc4462) to head (4a1acff).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #263 +/- ## ========================================== + Coverage 67.99% 68.05% +0.05% ========================================== Files 6 6 Lines 3309 3296 -13 ========================================== - Hits 2250 2243 -7 + Misses 1059 1053 -6 ```

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