Eloquent JavaScript 0504 Dominant writing direction.js https://eloquentjavascript.net/05_higher_order.html#i_4ccl4J1nOw

Eloquent JavaScript 0504 Dominant writing direction.js

function dominantDirection(text) {
  // Your code here.
  const directions = countBy(text, (char) => {
  	const script = characterScript(char.codePointAt(0));
    return script ? script.direction : 'none';
  }).filter(({ name }) => name != 'none');

  if (directions.length < 2) return directions[0].name;
  return directions.reduce((a, b) => a.count > b.count ? a.name : b.name);
}

console.log(dominantDirection("Hello!"));
// → ltr
console.log(dominantDirection("Hey, مساء الخير"));
// → rtl