Re: [PATCH v6 0/1] MR3391: mshtml: implement window.MutationObserver with MutationObserver stub

[Gabriel Ivăncescu (＠insn)]

Gabriel Ivăncescu (@insn) commented about dlls/mshtml/mutation.c:
> -
>    return E_INVALIDARG;
> -
> - callback = params->rgvarg + (params->cArgs - 1);
> - if (V_VT(callback) != VT_DISPATCH)
> -
>    return E_INVALIDARG;
> -
> - hres = create_mutation_observer(dispex_compat_mode(&This->dispex), V_DISPATCH(callback),
> -
>                                &mutation_observer);
> - if (FAILED(hres))
> -
>    return hres;
> -
> - V_VT(res) = VT_DISPATCH;
> - V_DISPATCH(res) = (IDispatch*)mutation_observer;
> -
> - return S_OK;
>
> +}

Please add some basic tests for the constructor, I suggested some earlier, but now since you can instantiate the object, I suggest some like:

* What happens if you construct with more than 1 arg? Probably it ignores further args rather than giving error.
* What happens if you pass a null to callback? Or a number, for example? Does it give error or simply ignores it?
* I think you should ignore named args, the rest of the code doesn't really deal with them, and you only have one arg to care about anyway.