Adds a flag to disable legacy mode. Currently this flag is used to cause
legacy mode apis like render and hydrate to throw. This change also
removes render, hydrate, unmountComponentAtNode, and
unstable_renderSubtreeIntoContainer from the experiemntal entrypoint.
Right now for Meta builds this flag is off (legacy mode is still
supported). In OSS builds this flag matches __NEXT_MAJOR__ which means
it currently is on in experiemental. This means that after merging
legacy mode is effectively removed from experimental builds. While this
is a breaking change, experimental builds are not stable and users can
pin to older versions or update their use of react-dom to no longer use
legacy mode APIs.
This pattern is a petpeeve of mine. I don't consider this best practice
and so most don't have these prefixes. Very inconsistent.
At best this is useless and noisey that you have to parse because the
information is also in the stack trace.
At worse these are misleading because they're highlighting something
internal (like validateDOMNesting) which even suggests an internal bug.
Even the ones public to React aren't necessarily what you called because
you might be calling a wrapper around it.
That would be properly reflected in a stack trace - which can also
properly ignore list so that the first stack you see is your callsite,
Which might be like `render()` in react-testing-library rather than
`createRoot()` for example.
Ricky
Josh Story
Sebastian Markbåge
Jack Pope