Split string by spaces, but not spaces within newlines, and preserve newlines

I have a string like this:

"word1 word2 \ngroup of words\n"

I need to split it by spaces except for the spaces that occur between 2 \n, and preserve the \n character. So the result would be an array like this:

[
 "word1",
 "word2",
 "\ngroup of words\n"
]

I've found results that achieve the same thing with , instead of \n, but it's not possible for me to replace it with any other character.

I'm currently using the code below, but it doesn't preserve the \n.

input.split('\n').flatMap((s,i)=>i%2?`\n${s.trim()}\n`:s.trim().split(' ')).filter(v=>v)

Notes:

If the input string has words before \n, there will always be a space before it, i.e. a string can contain word1 \ngroup 1\n, but never word1\ngroup 1\n

A string can also contain multiple groups, like word1 \ngroup 1\n word2 \ngroup 2\n