It's probably a brittle solution, but for the strings provided ...

this one is the GOAT

I'm just curious as to why this isn't the "best practice" it's this the "best" way to break the code down?

He needs to assign ("a" === array) to compare between the current e (element) and the next element a[i+1] so he can return any of the three options.

I understand that "a" in the filter iterations is the input array. Is there a benefit to using "a" in the filter iterations over "array"?

My favorite one so far! Looks pretty neat.

Hello,

What would be the difference between (/ /g, "") and (/\s/g, "")? Are they the exact same? Which one is best practice?

Best,
Maurizio A.

Is it odd or not that for an ES6-centric challenge, they are using pre-ES6 function formatting?

It took some time to realize how the logic works. An interesting solution but a little bit confusing.

Suggestion for initial code sample
From:
function spinWords(){
//TODO Have fun :)
}
To:
function spinWords(words){
//TODO Have fun :)
}

Instead of re.findall(..)[0] you could write re.search(...).

Oh c'mon. It's not a competition who the best uglifier

Oh c'mon. It's not a competition who the best uglifier