fix: crash on split

[ricardogobbosouza]

This PR contains a:

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

Motivation / Use-Case

Fix #61

Breaking Changes

Additional Info

[codecov]

Codecov Report

Merging #63 (5dc80fd) into master (d72a680) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master       #63   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            8         8           
  Lines          239       239           
  Branches        65        65           
=========================================
  Hits           239       239           

Impacted Files	Coverage Δ
src/index.js	100.00% <100.00%> (ø)

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[mmmulani]

if module.resource is undefined, you'll end up with file === "undefined". It'll work but seems like bad form, why not just check that module.resource is valid or use ?.