I wonder whether the inquirer prompts would work well in a middleware callback so "outside" the handler. But not sure makes any practical difference! I'll do a little digging...

Putting the code in middleware does work fine but I didn't find an advantage other than the separation, so probably better keeping the code simpler.

I did notice some things with async await if we wanted to say access username later on in a different function. We would just need to await the whole yargs function, something like this (in order to console.log out the username):

const argv = await yargs(hideBin(process.argv))
  .command({
    command: "login [username]",
    describe: "Prints out the username",
    builder: (yargs) => {
      yargs.positional("username", {
        describe: "The username to be printed",
        type: "string",
      });
    },
    handler: async (argv) => {
      if (!argv.username) {
        argv.username = await input({ message: "Please enter your username" });
      }

      console.log(`Welcome back, ${argv.username}!`);
    },
  })
  .help()
  .parse();

console.log(argv.username);

Would it be helpful to mention this in this inquirer section? There might be more specific documentation on async await so it might not be needed.

Good question about async. I don't think need to explicitly refactor code or explain about async since main point of example is inquirer, but I do think should add await in example code as good practice when have an async handler.

await yargs(hideBin(process.argv))
...

Sounds good, thanks for all the help. Went ahead and pushed those changes

@nephh thank you for the contribution.