index.html

<script>
window.onerror = function () {
  console.log(arguments);
};
</script>

<script>

(function () {
 (function () {
    try {
      (1 + 1, atob());
    } catch (e) {
      alert(e.stack);
    }
  })();


})();

</script>

<script>

throw new Error"hmorning");
</script>

<pre>
// e.g. 1
      "foo"; throw new Error("moo");
123456789'123456789"123456789#123456

Chrome: 20  index of 'new'
Safari: 36  index of ';'
IE    : 14  index of 'throw'
FF    : 20  index of 'new'


// e.g 2
      alert(window.foo.bar);
123456789'123456789"123456789#123456

Chrome: 23  index of '.'
Safari: 23  index of '.'
IE    :  7  index of 'alert'
FF    :  7  index of 'alert'


// e.g. 3
      alert(foo.bar);
123456789'123456789"123456789#123456

Chrome: 13  index of 'foo'
Safari: 16  index of '.'
IE    : 7   index of 'alert'
FF    : 7   index of 'alert'


// e.g. 4
      alert(window.atob());
123456789'123456789"123456789#123456

Chrome: 20  index of 'atob'
Safari: 24  index of '()'
IE    : 7   index of 'alert'
FF    : 7   index of 'alert'

// e.g. 5
      (1 + 1, atob());
123456789'123456789"123456789#123456

Chrome: 15  index of 'atob'
Safari: 19  index of '()'
IE    : 15  index of 'atob'
FF    :  8  index of '1'

</pre>