How do you split a long piece of text into separate lines? Why does this return line1 twice?

/^(.*?)$/mg.exec('line1rnline2rn');

[line1, line1]

I turned on the multi-line modifier to make ^ and $ match beginning and end of lines. I also turned on the global modifier to capture all lines.

I wish to use a regex split and not String.split because I'll be dealing with both Linux n and Windows rn line endings.