Flags tell your user that this function does more than one thing.
Functions should do one thing. Split out your functions if they are following different code paths based on a boolean.
Bad:
function createFile(name: string, temp: boolean) {
if (temp) {
fs.create(`./temp/${name}`);
} else {
fs.create(name);
}
}Good:
function createTempFile(name: string) {
createFile(`./temp/${name}`);
}
function createFile(name: string) {
fs.create(name);
}