Handle self referenced union string

[jepperaskdk]

Solves #55

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.78%. Comparing base (23224d3) to head (def1946).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #57      +/-   ##
==========================================
+ Coverage   92.75%   92.78%   +0.02%     
==========================================
  Files          13       13              
  Lines         773      776       +3     
  Branches      134      135       +1     
==========================================
+ Hits          717      720       +3     
  Misses         35       35              
  Partials       21       21              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.