fix: calling middleware in add should find open ports. fixes #130

[shellscape]

This PR contains a:

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

Motivation / Use-Case

Fixes #130

Breaking Changes

None

Additional Info

Tests not updated as code paths not technically changed, only moved.

[codecov]

Codecov Report

Merging #133 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master     #133   +/-   ##
=======================================
  Coverage   96.65%   96.65%           
=======================================
  Files           7        7           
  Lines         269      269           
=======================================
  Hits          260      260           
  Misses          9        9

Impacted Files	Coverage Δ
lib/server.js	93.1% <100%> (ø)	⬆️

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[alexander-akait]

Maybe add test for avoid regression?

[shellscape]

@evilebottnawi I couldn't come up with a good regression test for this case. More than happy to accept a PR if you have an idea for one.