Поиск символа в строке с помощью javascript

const verify = username => !/[#\$/@]/.test(username);
console.info(verify('foo'));
console.info(verify('foo#'));
console.info(verify('foo!'));
console.info(verify('f$oo'));

var pattern = /[$#@/]+/;
var username = "prachi.user";
var hasInvalidChar = pattern.test(username);
if (hasInvalidChar) {
  alert("Case 1 - Invalid");
} else {
  alert("Case 1 - Valid");
}


var pattern = /[$#@/]+/;
var username = "prachi.user#$@#/";
var hasInvalidChar = pattern.test(username);
if (hasInvalidChar) {
  alert("Case 2 - Invalid");
} else {
  alert("Case 2 - Valid");
}