tests: Add test for NewStoragerFromString

[JinnyYi]

No description provided.

[codecov]

Codecov Report

Merging #724 (17931b4) into master (841f5c1) will increase coverage by 0.19%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #724      +/-   ##
==========================================
+ Coverage   12.36%   12.55%   +0.19%     
==========================================
  Files          22       22              
  Lines        1488     1473      -15     
==========================================
+ Hits          184      185       +1     
+ Misses       1297     1281      -16     
  Partials        7        7              

Flag	Coverage Δ
unittests	12.55% <100.00%> (+0.19%)	⬆️

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Impacted Files	Coverage Δ
tests/storage.go	0.00% <ø> (ø)
tests/utils.go	33.33% <100.00%> (+16.66%)	⬆️

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[Xuanwo]

Great work!