Remove empty values, trim whitespace and removes duplicate from a comma separated string in JavaScript

javascript-clean-csv-string.js

/**
 * Removes empty values, trims whitespace and removes duplicate from a comma separated string in JavaScript
 * @example
 *  cleanCsvString('one, ,, , two,two,two, three'); // returns 'one,two,three'
 *  cleanCsvString('one, ,, , two,two,two, three', false); // returns 'one,two,two,two,three'
 * @param {string} str - string to modify
 * @param {boolean} removeDuplicates - should remove duplicate items? (default = true)
 * @returns {string} cleaned CSV string
 */
function cleanCsvString(str, removeDuplicates) {

    // default to true
    removeDuplicates = (removeDuplicates === undefined) ? true : removeDuplicates;

    // go through each item
    return String(str).split(',').map(function(item) {
        // trim value
        return String(item).trim();
    })
    .filter(function(item, index, all) {

        if (removeDuplicates) {
            // remove empty items & duplicate values
            return (item !== '') && (index === all.indexOf(item));
        }

        return item;
    })
    .join(',');
}

cleanCsvString('one, ,, , two,two,two, three'); returns 'one,two,three'