chore: improve unit tests

[ubogdan]

Describe the PR
improve unit tests

Relation issue
None

Additional context
None

[codecov]

Codecov Report

Merging #1123 (5a04fa6) into master (b1e10b7) will increase coverage by 0.17%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1123      +/-   ##
==========================================
+ Coverage   94.66%   94.84%   +0.17%     
==========================================
  Files          10       10              
  Lines        2399     2404       +5     
==========================================
+ Hits         2271     2280       +9     
+ Misses         67       65       -2     
+ Partials       61       59       -2     

Impacted Files	Coverage Δ
formater.go	100.00% <100.00%> (ø)
operation.go	95.91% <0.00%> (+0.05%)	⬆️
packages.go	85.87% <0.00%> (+2.25%)	⬆️

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