We now query selector and take textContent synchronously. This
avoids any issues with async processing: node being recycled,
detached, etc.
More methods will follow with the same atomic pattern.
Drive-by: fixed selector engine names being sometimes case-sensitive
and sometimes not.
We currently have dispatchEventTask and waitForSelectorTask.
However, most selector-based operations make sense as tasks, to ensure
atomic execution, e.g. textContent(selector) or focus(selector).
This will fight hydration, elements recycling and other async issues.
In preparation, decouple tasks from selectors parsing so that
we can have common infrastructure for tasks.
- Gave all possible dom errors distinct names, and throw them on the node side.
- Separated errors into FatalDOMError and RetargetableDOMError.
Fatal errors are unrecoverable. Retargetable errors
could be resolved by requerying the selector.
- This exposed a number of unhandled 'notconnected' cases.
- Added helper functions to handle errors and ensure TypeScript catches
unhandled ones.
- unifies polling timeouts with everything else,
based on the client time instead of the server time;
- prepares polling tasks for cancellation token
behavior.
Unfortunately, RerunnableTask had to be rewritten almost
entirely.
This introduces the `*name=body` syntax to capture intermediate result.
For example, `*css=section >> "Title"` will capture a section that contains "Title".
This encapsulates selectors logic in one place, in a preparation for more complex scenarios like main-world selectors or piercing frames.
Note: we had `Page.fill should wait for visible visibilty` test, but we do not actually wait for visible in page.fill(). It happened to pass due to lucky evaluation order.
References #1316.
