Filter out empty elements when creating command strings

[christophebedard]

Follow-up to #608, which didn't fix every occurrence.

[codecov]

Codecov Report

Merging #609 (d8fe2fe) into master (bd36a6b) will increase coverage by 0.55%.
The diff coverage is 37.50%.

❗ Current head d8fe2fe differs from pull request most recent head 5dde110. Consider uploading reports for the commit 5dde110 to get more accurate results

@@            Coverage Diff             @@
##           master     #609      +/-   ##
==========================================
+ Coverage   38.28%   38.83%   +0.55%     
==========================================
  Files           2        2              
  Lines         222      224       +2     
  Branches       42       43       +1     
==========================================
+ Hits           85       87       +2     
  Misses        137      137              

Impacted Files	Coverage Δ
src/action-ros-ci.ts	29.74% <37.50%> (+0.72%)	⬆️

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[christophebedard]

Looking at the tests now, it all looks good.

[emersonknapp]

these are all fine, but now that we are doing it 4 times, i wonder if a utility function would be warranted, e.g.

function filterNonEmptyJoin(values: List) {
  return values.filter((v) => v.length > 0).join(" ")
}

[christophebedard]

sure I can do that!

I can even add a test 😁

[christophebedard]

utility function

done in 1ed8912 with test in 5dde110

[emersonknapp]

nice, thanks