pluralize word (use regular plural rules => works only on regular words)

pluralize.js

/*
plural rules
	regular
		if -s, -x, -ch or -sh then add -es
		if -{consonant}y then remove -y and add -ies
		else add -s

	irregular
		if -f then remove -f and add -ves
		if -fe then remove -fe and add -ves
		if -us then remove -us and add -i
		if -o then add -es
*/

module.exports = function pluralize (word) {
	if (!word) return '';

	word = word.split('');

	var s /* size */ = word.length;
	var p /* penultimate */ = word[s - 2];
	var l /* last */ = word[s - 1];

	if (l == 's' || l == 'x' || l == 'h' && p == 'c' || p == 's') {
		word.push('es')
	} else {
		if (l == 'y' && !(p == 'a' || p == 'e' || p == 'i' || p == 'o' || p == 'u' || p == 'y')) {
			word.splice(s - 1, 1, 'ies')
		} else {
			word.push('s');
		}
	}

	return word.join('');
};