You could use notEqual(MockOptionMenu.calls[0].items[2].l10nId, 'resend-message') here.
BTW, it seems not a proper way to verify resend is existed or not in specific position of items array. Maybe we should check each item here?
```
function hasResend(element) {
  return (element.l10nId === 'resend-message');
}
assert.isFalse(MockOptionMenu.calls[0].items.some(hasResend));
```
Something like that(but I didn't try it :p)