[JS] Make unique the items of an array

only_unique.js

/**
 * Callback that makes unique the items of an array.
 *
 * Example usage:
 *   var myArray = ['a', 1, 'a'];
 *   var myUniqueArray = myArray.filter(onlyUnique);
 *
 * @param arrayItem one of the items of the array
 * @param {number} arrayIndex
 * @param {Array} arrayToMakeUnique
 *
 * @returns {boolean}
 *
 * @see https://stackoverflow.com/questions/1960473/get-all-unique-values-in-a-javascript-array-remove-duplicates
 */
onlyUnique: function (arrayItem, arrayIndex, arrayToMakeUnique) {
    const arrayOfJsonizedItems = arrayToMakeUnique.map(JSON.stringify);
    const jsonizedItem = JSON.stringify(arrayItem);
    return arrayOfJsonizedItems.indexOf(jsonizedItem) === arrayIndex;
}