Improve test coverage

[codecov[bot]]

Codecov Report

Merging #18 (c3c84cf) into main (523dee2) will increase coverage by 6.09%. The diff coverage is 88.98%.

@@            Coverage Diff             @@
##             main      #18      +/-   ##
==========================================
+ Coverage   54.15%   60.24%   +6.09%     
==========================================
  Files          22       22              
  Lines        1673     1766      +93     
==========================================
+ Hits          906     1064     +158     
+ Misses        767      702      -65     

Files Changed	Coverage Δ
src/args.rs	0.00% <0.00%> (ø)
src/cmd/configure.rs	0.00% <0.00%> (ø)
src/main.rs	0.00% <0.00%> (ø)
src/settings.rs	77.09% <94.66%> (+52.09%)	:arrow_up:
src/config.rs	96.47% <97.05%> (+79.52%)	:arrow_up:
src/cache.rs	36.87% <100.00%> (ø)