More unit tests

[joaquimg]

Tests suggested by Claude, they seem meaningful.

• First was apparently only being tested implicitly
• Second is an untested corner case

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.85%. Comparing base (6b74af4) to head (ade1867).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #237   +/-   ##
=======================================
  Coverage   99.85%   99.85%           
=======================================
  Files           9        9           
  Lines        2009     2009           
=======================================
  Hits         2006     2006           
  Misses          3        3           

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