Summary:
This change is in preparation of adding a separate `VirtualizedList_EXPERIMENTAL` component.
Both the original, and experimental lists use `VirtualizedListContext`, which itself references back to the VirtualizedList class type. VirtualizedList private methods are currently included in the type system, and are called in other VirtualizedList code (see https://github.com/facebook/react-native/commit/b2f871a6fa9c92dd0712055384b9eca6d828e37d). This prevents Flow from seeing the two classes are compatible if "private" methods change.
My first attempt was to parameterize the context, to allow both `VirtualizedList`, and `VirtualizedList_EXPERIMENTAL` to use the same code without sacrificing type safety or adding further duplication. This added more complexity than it is worth, so I am instead loosening the type on VirtualizedListContext to pass around a more generic handle.
Changelog:
[Internal][Changed] - Allow VirtualizedListContext to support different component type
Reviewed By: javache
Differential Revision: D38017086
fbshipit-source-id: 91e8f6ab2591d3ae9b7f9263711b4a39b78f68e0
Nick Gerleman
04e43544b8