Practical task: write a function that takes a number and returns a Promise with the result of checking for even/odd, and on error (not a number) returns -1.

A function that takes a number and returns a Promise with the result of checking for even/odd, and returns -1 on error, might look like this:

function checkParity(value: any): Promise<string | number> {
  return new Promise((resolve) => {
    if (typeof value !== 'number' || isNaN(value)) {
      resolve(-1);
    } else if (value % 2 === 0) {
      resolve('even');
    } else {
      resolve('odd');
    }
  });
}

// Example usage:
checkParity(4).then(console.log); // "even"
checkParity(7).then(console.log); // "odd"
checkParity('abc').then(console.log); // -1

Here, we check the type and validity of the input value, and return the result in a Promise, which is convenient for asynchronous use.