test: errors from terser

[alexander-akait]

This PR contains a:

• bugfix
• new feature
• code refactor
• test update
• typo fix
• metadata update

Motivation / Use-Case

check what propagate errors from Terser

Breaking Changes

No

Additional Info

No

[codecov]

Codecov Report

Merging #179 into master will decrease coverage by 0.28%.
The diff coverage is 80%.

@@            Coverage Diff            @@
##           master    #179      +/-   ##
=========================================
- Coverage   99.39%   99.1%   -0.29%     
=========================================
  Files           5       5              
  Lines         333     337       +4     
  Branches      139     143       +4     
=========================================
+ Hits          331     334       +3     
- Misses          2       3       +1

Impacted Files	Coverage Δ
src/index.js	99.02% <80%> (-0.48%)	⬇️

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