Well, it would be more accurate to rely on the feature and not a variable value. Especially as there are 2 possible variables for Windows.
function getUserHome() {
return process.env.HOME || process.env.USERPROFILE;
}
EDIT: as mentioned in a more recent answer, https://stackoverflow.com/a/32556337/103396 is the right way to go (require('os').homedir()
).