const characterSets = require('character-sets');
 
// array of character sets
characterSets.toArray(); // ['UTF-8', ...]
 
// lower cased character set array
characterSets.normalize(); // ['utf-8', ...]
 
// is my character set a standardized character set?
characterSets.includes('utf-8'); // true
characterSets.includes('UTF-8'); // true
characterSets.includes('US-ASCII'); // true
characterSets.includes('us-ascii'); // true
characterSets.includes('pikachu'); // false