DOMException: The selector ":nth-of-type" is not valid.

[U-Zo]

In the case of nested selectors, it is not valid.

e.g.)

p:not(:nth-of-type(1))

[gdorsi]

Got the same issue!

I've isolated the problem to SELECTOR_REGEXP which doesn't support pseudo selectors as arguments of other pseudo-selectors: https://github.com/capricorn86/happy-dom/blob/master/packages/happy-dom/src/query-selector/SelectorParser.ts#L22

This is a repro test:

it("Has support for nesting pseudo selectors inside pseudo-selectors arguments", () => {
  const div = document.createElement("div");
  const child = document.createElement("div");
  const child2 = document.createElement("div");

  div.appendChild(child);
  div.appendChild(child2);

  expect(div.querySelector(":not(:nth-child(1))")).toBe(child2);
});