Two string - JavaScript - RegExp expression

Twostring13.cs

function processData(input) {
    var data = input.split('\n');
    for (var i = 1; i < data.length; i += 2) {
        var pattern = '[' + data[i] + ']';
        var reg = new RegExp(pattern);        
        console.log(reg.test(data[i+1]) ? 'YES' : 'NO');
    }
} 

process.stdin.resume();
process.stdin.setEncoding("ascii");
_input = "";
process.stdin.on("data", function (input) {
    _input += input;
});

process.stdin.on("end", function () {
   processData(_input);
});