This patch adds support for the `vue` selector engine that allows
selecting DOM elements based on the component name.
> **NOTE**: `vue` engine supports Vue2 and Vue2.
References #7189
This patch adds support for the `react` selector engine that allows
selecting DOM elements based on the component name.
> **NOTE**: in case of multi-root components (React.Fragment), `react`
engine will select all root DOM elements.
> **NOTE**: `react` engine supports react v15+.
References #7189
When parsing CSS, we assume everything is a valid CSS function,
unless it is in the list of custom functions. This way we'll parse
future CSS functions automatically.
This is a large rework of selectors:
- Each BrowserContext now has a separate Selectors instance that has its own registrations.
Most of them share a single sharedSelectors instance, but contexts created for a connected
browser have their own instance.
- Connected browser now gets a RemoteBrowser object that encapsulates Selectors and Browser.
This Selectors object is registered with the api selectors.
- Public selectors.register api iterates over all registered Selectors channels
and registers in each of them.
- createSelector testing method migrated to ElementHandle._createSelectorForTest.