InvalidOperationException with valid CSS selector

[danbopes]

This should be perfectly valid syntax for a CSS selector, and yields the correct result in chrome:

select[name='extra[isFoil]']

This should not throw an error:

[humbertomoli99]

try with use \" selector += "[" + "itemprop=\"" + el.getAttribute("itemprop") + "\"]";

select[name=\"extra[isFoil]\"]"