This type isn't exported so it's technically not public.
This object mimics a ReadableStream.
Currently this is safe to destructure and call separately but I'm not sure
that's even guaranteed. It should probably be treated as a class in docs.
The Profiler has an advanced feature that shows why a component re-rendered. In the case of props and (class) state, it shows the names of props/state values that changed between renders. For hooks, DevTools tries to detect which ones may been related to the update by comparing prev/next internal hook structures.
My initial implementation tried to detect all changed hooks. In hindsight this is confusing, because only stateful hooks (e.g. useState, useReducer, and useSyncExternalStore) can schedule an update. (Other types of hooks can change between renders, but in a reactive way.) This PR changes the behavior to only report hooks that scheduled the update.
We were suppressing the `react-internals/warning-args` lint rule
for the call to `console.error` in `defaultOnRecoverableError`.
As far as I could tell, the lint rule exists because on dev builds,
we replace all calls to `console.error` with [this error
function](https://github.com/facebook/react/blob/main/packages/shared/consoleWithStackDev.js#L31-L37)
which expects a format string + args and nothing else. We were trying
to pass in an `Error` object directly. After this commit's change,
we will still be passing an `Error` but the transform won't occur.
We used to listen to at the document level for this event. That allowed us to listen to up/down arrow key events while another section
of DevTools (like the search input) was focused. This was a minor UX positive.
(We had to use ownerDocument rather than document for this, because the DevTools extension renders the Components and Profiler tabs into portals.)
This approach caused a problem though: it meant that a react-devtools-inline instance could steal (and prevent/block) keyboard events from other JavaScript on the page– which could even include other react-devtools-inline instances. This is a potential major UX negative.
Given the above trade offs, we now listen on the root of the Tree itself.
* Pass children to hydration root constructor
I already made this change for the concurrent root API in #23309. This
does the same thing for the legacy API.
Doesn't change any behavior, but I will use this in the next steps.
* Add isRootDehydrated function
Currently this does nothing except read a boolean field, but I'm about
to change this logic.
Since this is accessed by React DOM, too, I put the function in a
separate module that can be deep imported. Previously, it was accessing
the FiberRoot directly. The reason it's a separate module is to break a
circular dependency between React DOM and the reconciler.
* Allow updates at lower pri without forcing client render
Currently, if a root is updated before the shell has finished hydrating
(for example, due to a top-level navigation), we immediately revert to
client rendering. This is rare because the root is expected is finish
quickly, but not exceedingly rare because the root may be suspended.
This adds support for updating the root without forcing a client render
as long as the update has lower priority than the initial hydration,
i.e. if the update is wrapped in startTransition.
To implement this, I had to do some refactoring. The main idea here is
to make it closer to how we implement hydration in Suspense boundaries:
- I moved isDehydrated from the shared FiberRoot object to the
HostRoot's state object.
- In the begin phase, I check if the root has received an by comparing
the new children to the initial children. If they are different, we
revert to client rendering, and set isDehydrated to false using a
derived state update (a la getDerivedStateFromProps).
- There are a few places where we used to set root.isDehydrated to false
as a way to force a client render. Instead, I set the ForceClientRender
flag on the root work-in-progress fiber.
- Whenever we fall back to client rendering, I log a recoverable error.
The overall code structure is almost identical to the corresponding
logic for Suspense components.
The reason this works is because if the update has lower priority than
the initial hydration, it won't be processed during the hydration
render, so the children will be the same.
We can go even further and allow updates at _higher_ priority (though
not sync) by implementing selective hydration at the root, like we do
for Suspense boundaries: interrupt the current render, attempt hydration
at slightly higher priority than the update, then continue rendering the
update. I haven't implemented this yet, but I've structured the code in
anticipation of adding this later.
* Wrap useMutableSource logic in feature flag
dan
Sebastian Markbåge
zhoulixiang
Sebastian Silbermann
alireza molaee
Hikari Hayashi
Noel Kim (김민혁)
Luna Ruan
Mengdi "Monday" Chen
Kayanddan
Brian Vaughn
Andrew Clark
Strek
Yash Srivastav
salazarm
