gistfile1.txt

var assert = require('assert');

function symmetryPoint ( S ) {
    if (S.length % 2 === 0) {
	    return -1;
    } else {
	var middle = Math.floor(S.length / 2);

	var front = S.substr(0, middle);
	var back = S.substr(middle+1, S.length);

	if (front === reverse(back)) {
	    return middle;
	} else {
	    return -1;
	}
    }

    function reverse(s){
	return s.split("").reverse().join("");
    }
}

console.log('run');
var out1 = symmetryPoint("racecar");
console.log('out1', out1);
assert.equal(out1, 3);
var out2 = symmetryPoint("x");
console.log('out2', out2);
assert.equal(out2, 0);
var out3 = symmetryPoint("xy");
console.log('out3', out3);
assert.equal(out3, -1);
var out4 = symmetryPoint("xyz");
console.log('out4', out4);
assert.equal(out4, -1);