Fixed expressions substitution

[AlexMost]

Original issue - #153

• Fixed expressions substitution
• Fixed expressions regex (computed properties were not supported
• Added more test cases

[codecov]

Codecov Report

Merging #155 into master will decrease coverage by 0.2%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #155      +/-   ##
==========================================
- Coverage   96.81%   96.61%   -0.21%     
==========================================
  Files           4        4              
  Lines         471      472       +1     
  Branches       70       70              
==========================================
  Hits          456      456              
- Misses         15       16       +1

Impacted Files	Coverage Δ
src/utils.js	92.13% <100%> (-0.53%)	⬇️

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