readText will do just that, read the text, so if it reads different line endings than the host OS it won't bother differentiating
however, kotlin lineSequence is a different story: it will split lines even with mixed line endings (CR, LF, or CR): https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.text/line-sequence.html
you might also take a look at useLines, forEachLine, and readLines for files