Get the real length of a string with hex codes. Useful when looping through a string.

truelength.js

// get true length of a a string with colors
// this is necessary since javascript counts everything in the string
// which is not good when you are looping a string
// mainly when you are using it to make it even with the terminal size

// you can pass it to String.prototype and remove the test of string
const length = str => {
  //always string
  if (!str || typeof str !== 'string')
    return 0;

 let matches = str.match(/\[\d+m/g);

 if (matches)
    matches = matches.join('').length;

  let lengthHex = 0;

  const hexs = str.split('');

  if (hexs) {
    for (l of hexs) {
      if (l === '\x1B')
        lengthHex++;
    }
  }

  return (lengthHex + matches - str.length) * -1;
}

// string with hex and color to print in terminal

// \x1B or \x1b = hex to color
// [7m = color
// [0m = reset to normal color
const teste = '\x1B[7mteste\x1B[0m';

console.log(teste, teste.length);
// > teste 13

console.log(teste, trueLength(teste));
// > teste 5