←

Let's import child_process's exec function as a promise:

 const util = require("util")   
 const exec  = util.promisify(require("child_process").exec)

Then we run exec with a current working directory argument, if we want, and then wait upon the result of such:

exec("ls -l", { cwd: "/home/bees/and/bees/" })
.then((stdout, stderr) => {
  console.log("completed program", stdout, stderr)
})
.catch(e => {
  console.log("failed to start program", e)
})