<!--
Thanks for submitting a pull request!
We appreciate you spending the time to work on these changes. Please
provide enough information so that others can review your pull request.
The three fields below are mandatory.
Before submitting a pull request, please make sure the following is
done:
1. Fork [the repository](https://github.com/facebook/react) and create
your branch from `main`.
2. Run `yarn` in the repository root.
3. If you've fixed a bug or added code that should be tested, add tests!
4. Ensure the test suite passes (`yarn test`). Tip: `yarn test --watch
TestName` is helpful in development.
5. Run `yarn test --prod` to test in the production environment. It
supports the same options as `yarn test`.
6. If you need a debugger, run `yarn test --debug --watch TestName`,
open `chrome://inspect`, and press "Inspect".
7. Format your code with
[prettier](https://github.com/prettier/prettier) (`yarn prettier`).
8. Make sure your code lints (`yarn lint`). Tip: `yarn linc` to only
check changed files.
9. Run the [Flow](https://flowtype.org/) type checks (`yarn flow`).
10. If you haven't already, complete the CLA.
Learn more about contributing:
https://reactjs.org/docs/how-to-contribute.html
-->
## Summary
In order to adopt react 19's ref-as-prop model, Flow needs to eliminate
all the places where they are treated differently.
`React.AbstractComponent` is the worst example of this, and we need to
eliminate it.
This PR eliminates them from the react repo, and only keeps the one that
has 1 argument of props.
## How did you test this change?
yarn flow
Adds tests for Compiler integration.
This includes:
- Tests against Compiler from source.
- Versioned (18.2 - <19) tests against Compiler from npm.
For tests against React 18.2, I had to download `react-compiler-runtime`
from npm and put it to `react/compiler-runtime.js`.
In #31140 we switched over the uMC polyfill to use memo instead of state
since memo would FastRefresh properly. However this busted devtools'
badging of compiled components; this PR fixes it.
TODO: tests
Co-authored-by: Ruslan Lesiutin <rdlesyutin@gmail.com>
---------
Co-authored-by: Ruslan Lesiutin <rdlesyutin@gmail.com>
Fixes tests against React 18 after
https://github.com/facebook/react/pull/31154:
- Set `supportsTimeline` to true for `Store`.
- Execute `store.profilerStore.startProfiling` after `legacyRender`
import, because this is where `react-dom` is imported and renderer is
registered. We don't yet propagate `isProfiling` flag to newly
registered renderers, when profiling already started see:
d5bba18b5d/packages/react-devtools-shared/src/hook.js (L203-L204)
Stacked on https://github.com/facebook/react/pull/31132. See last
commit.
There are 2 issues:
1. We've been recording timeline events, even if Timeline Profiler was
not supported by the Host. We've been doing this for React Native, for
example, which would significantly regress perf of recording a profiling
session, but we were not even using this data.
2. Currently, we are generating component stack for every state update
event. This is extremely expensive, and we should not be doing this.
We can't currently fix the second one, because we would still need to
generate all these stacks, and this would still take quite a lot of
time. As of right now, we can't generate a component stack lazily
without relying on the fact that reference to the Fiber is not stale.
With `enableOwnerStacks` we could populate component stacks in some
collection, which would be cached at the Backend, and then returned only
once Frontend asks for it. This approach also eliminates the need for
keeping a reference to a Fiber.
Stacked on https://github.com/facebook/react/pull/31131. See last
commit.
This is a clean-up and a pre-requisite for next changes:
1. `ReloadAndProfileConfig` is now split into boolean value and settings
object. This is mainly because I will add one more setting soon, and
also because settings might be persisted for a longer time than the flag
which signals if the Backend was reloaded for profiling. Ideally, this
settings should probably be moved to the global Hook object, same as we
did for console patching.
2. Host is now responsible for reseting the cached values, Backend will
execute provided `onReloadAndProfileFlagsReset` callback.
Based on https://github.com/facebook/react/pull/31049, credits to
@EdmondChuiHW.
What is happening here:
1. Once Agent is destroyed, unsubscribe own listeners and bridge
listeners.
2. [Browser extension only] Once Agent is destroyed, unsubscribe
listeners from BackendManager.
3. [Browser extension only] I've discovered that `backendManager.js`
content script can get injected multiple times by the browser. When
Frontend is initializing, it will create Store first, and then execute a
content script for bootstraping backend manager. If Frontend was
destroyed somewhere between these 2 steps, Backend won't be notified,
because it is not initialized yet, so it will not unsubscribe listeners
correctly. We might end up duplicating listeners, and the next time
Frontend is launched, it will report an issues "Cannot add / remove node
...", because same operations are emitted twice.
To reproduce 3 you can do the following:
1. Click reload-to-profile
2. Right after when both app and Chrome DevTools panel are reloaded,
close Chrome DevTools.
3. Open Chrome DevTools again, open Profiler panel and observe "Cannot
add / remove node ..." error in the UI.
We can't wait for a response from Backend, because it might take some
time to actually finish profiling.
We should keep a flag on the frontend side, so user can quickly see the
feedback in the UI.
This allows us to show props in React DevTools when inspecting a Server
Component.
I currently drastically limit the object depth that's serialized since
this is very implicit and you can have heavy objects on the server.
We previously was using the general outlineModel to outline
ReactComponentInfo but we weren't consistently using it everywhere which
could cause some bugs with the parsing when it got deduped on the
client. It also lead to the weird feature detect of `isReactComponent`.
It also meant that this serialization was using the plain serialization
instead of `renderConsoleValue` which means we couldn't safely serialize
arbitrary debug info that isn't serializable there.
So the main change here is to call `outlineComponentInfo` and have that
always write every "Server Component" instance as outlined and in a way
that lets its props be serialized using `renderConsoleValue`.
<img width="1150" alt="Screenshot 2024-10-01 at 1 25 05 AM"
src="https://github.com/user-attachments/assets/f6e7811d-51a3-46b9-bbe0-1b8276849ed4">
<!--
Thanks for submitting a pull request!
We appreciate you spending the time to work on these changes. Please
provide enough information so that others can review your pull request.
The three fields below are mandatory.
Before submitting a pull request, please make sure the following is
done:
1. Fork [the repository](https://github.com/facebook/react) and create
your branch from `main`.
2. Run `yarn` in the repository root.
3. If you've fixed a bug or added code that should be tested, add tests!
4. Ensure the test suite passes (`yarn test`). Tip: `yarn test --watch
TestName` is helpful in development.
5. Run `yarn test --prod` to test in the production environment. It
supports the same options as `yarn test`.
6. If you need a debugger, run `yarn test --debug --watch TestName`,
open `chrome://inspect`, and press "Inspect".
7. Format your code with
[prettier](https://github.com/prettier/prettier) (`yarn prettier`).
8. Make sure your code lints (`yarn lint`). Tip: `yarn linc` to only
check changed files.
9. Run the [Flow](https://flowtype.org/) type checks (`yarn flow`).
10. If you haven't already, complete the CLA.
Learn more about contributing:
https://reactjs.org/docs/how-to-contribute.html
-->
## Summary
In preparation to support reload-to-profile in Fusebox (#31021), we need
a way to check capability of different backends, e.g. web vs React
Native.
## How did you test this change?
<!--
Demonstrate the code is solid. Example: The exact commands you ran and
their output, screenshots / videos if the pull request changes the user
interface.
How exactly did you verify that your PR solves the issue you wanted to
solve?
If you leave this empty, your PR will very likely be closed.
-->
* Default, e.g. existing web impl = no-op
* Custom impl: is called
React DevTools no longer operates with just Fibers, it now builds its
own Shadow Tree, which represents the tree on the Host (Fabric on
Native, DOM on Web).
We have to keep track of public instances for a select-to-inspect
feature. We've recently changed this logic in
https://github.com/facebook/react/pull/30831, and looks like we've been
incorrectly getting a public instance for Fabric case.
Not only this, turns out that all `getInspectorData...` APIs are
returning Fibers, and not public instances. I have to expose it, so that
React DevTools can correctly identify the element, which was selected.
Changes for React Native are in
[D63421463](https://www.internalfb.com/diff/D63421463)
Stacked on https://github.com/facebook/react/pull/31009.
1. Instead of keeping `showInlineWarningsAndErrors` in `Settings`
context (which was removed in
https://github.com/facebook/react/pull/30610), `Store` will now have a
boolean flag, which controls if the UI should be displaying information
about errors and warnings.
2. The errors and warnings counters in the Tree view are now counting
only unique errors. This makes more sense, because it is part of the
Elements Tree view, so ideally it should be showing number of components
with errors and number of components of warnings. Consider this example:
2.1. Warning for element `A` was emitted once and warning for element
`B` was emitted twice.
2.2. With previous implementation, we would show `3 ⚠️`, because in
total there were 3 warnings in total. If user tries to iterate through
these, it will only take 2 steps to do the full cycle, because there are
only 2 elements with warnings (with one having same warning, which was
emitted twice).
2.3 With current implementation, we would show `2 ⚠️`. Inspecting the
element with doubled warning will still show the warning counter (2)
before the warning message.
With these changes, the feature correctly works.
https://fburl.com/a7fw92m4
<!--
Thanks for submitting a pull request!
We appreciate you spending the time to work on these changes. Please
provide enough information so that others can review your pull request.
The three fields below are mandatory.
Before submitting a pull request, please make sure the following is
done:
1. Fork [the repository](https://github.com/facebook/react) and create
your branch from `main`.
2. Run `yarn` in the repository root.
3. If you've fixed a bug or added code that should be tested, add tests!
4. Ensure the test suite passes (`yarn test`). Tip: `yarn test --watch
TestName` is helpful in development.
5. Run `yarn test --prod` to test in the production environment. It
supports the same options as `yarn test`.
6. If you need a debugger, run `yarn test --debug --watch TestName`,
open `chrome://inspect`, and press "Inspect".
7. Format your code with
[prettier](https://github.com/prettier/prettier) (`yarn prettier`).
8. Make sure your code lints (`yarn lint`). Tip: `yarn linc` to only
check changed files.
9. Run the [Flow](https://flowtype.org/) type checks (`yarn flow`).
10. If you haven't already, complete the CLA.
Learn more about contributing:
https://reactjs.org/docs/how-to-contribute.html
-->
## Summary
Profiling fails sometimes because `onProfilingStatus` is called
repeatedly on some occasions, e.g. multiple calls to
`getProfilingStatus`.
Subsequent calls should be a no-op if the profiling status hasn't
changed.
Reported via #30661#28838.
> [!TIP]
> Hide whitespace changes on this PR
<img width="328" alt="screenshot showing the UI controls for hiding
whitespace changes on GitHub"
src="https://github.com/user-attachments/assets/036385cf-2610-4e69-a717-17c05d7ef047">
## How did you test this change?
<!--
Demonstrate the code is solid. Example: The exact commands you ran and
their output, screenshots / videos if the pull request changes the user
interface.
How exactly did you verify that your PR solves the issue you wanted to
solve?
If you leave this empty, your PR will very likely be closed.
-->
Tested as part of Fusebox implementation of reload-to-profile.
https://github.com/facebook/react/pull/31021?#discussion_r1770589753
Stacked on https://github.com/facebook/react/pull/30636. See [this
commit](20cec76c44).
This has been only used for React Native and will be replaced by another
approach (initialization via `installHook` call) in the next PR.
Stacked on https://github.com/facebook/react/pull/30610 and whats under
it. See [last
commit](248ddba186).
Now, we are using
[`chrome.storage`](https://developer.chrome.com/docs/extensions/reference/api/storage)
to persist settings for the browser extension across different sessions.
Once settings are updated from the UI, the `Store` will emit
`settingsUpdated` event, and we are going to persist them via
`chrome.storage.local.set` in `main/index.js`.
When hook is being injected, we are going to pass a `Promise`, which is
going to be resolved after the settings are read from the storage via
`chrome.storage.local.get` in `hookSettingsInjector.js`.
Stacked on https://github.com/facebook/react/pull/30597 and whats under
it. See [this
commit](59b4efa723).
With this change, the initial values for console patching settings are
propagated from hook (which is the source of truth now, because of
https://github.com/facebook/react/pull/30596) to the UI. Instead of
reading from `localStorage` the frontend is now requesting it from the
hook. This happens when settings modal is rendered, and wrapped in a
transition. Also, this is happening even if settings modal is not opened
yet, so we have enough time to fetch this data without displaying loader
or similar UI.
Stacked on https://github.com/facebook/react/pull/30596. See [this
commit](4ba5e784bb).
Moving `formatWithStyles` and `formatConsoleArguments` to its own
modules, so that we can finally have a single implementation for these
and stop inlining them in RDT global hook object.
Stacked on https://github.com/facebook/react/pull/30566 and whats under
it. See [this
commit](374fd737e4).
It is mostly copying code from one place to another and updating tests.
With these changes, for every console method that we patch, there is
going to be a single applied patch:
- For `error`, `warn`, and `trace` we are patching when hook is
installed. This guarantees that component stacks are going to be
appended even if browser DevTools are not opened. We pay some price for
it, though: if user has browser DevTools closed and if at this point
some warning or error is emitted (logged), the next time user opens
browser DevTools, they are going to see `hook.js` as the source frame.
Unfortunately, ignore listing from source maps is not applied
retroactively, and I don't know if its a bug or just a design
limitations. Once browser DevTools are opened, source maps will be
loaded and ignore listing will be applied for all emitted logs in the
future.
- For `log`, `info`, `group`, `groupCollapsed` we are only patching when
React notifies React DevTools about running in StrictMode. We unpatch
the methods right after it.
Right now we are patching console 2 times: when hook is installed
(before page is loaded) and when backend is connected. Because of this,
even if user had `appendComponentStack` setting enabled, all emitted
error and warning logs are not going to have component stacks appended.
They also won't have component stacks appended retroactively when user
opens browser DevTools (this is when frontend is initialized and
connects to backend).
This behavior adds potential race conditions with LogBox in React
Native, and also unpredictable to the user, because in order to get
component stacks logged you have to open browser DevTools, but by the
time you do it, error or warning log was already emitted.
To solve this, we are going to only patch console in the hook object,
because it is guaranteed to load even before React. Settings are going
to be synchronized with the hook via Bridge, and React DevTools Backend
Host (React Native or browser extension shell) will be responsible for
persisting these settings across the session, this is going to be
implemented in a separate PR.
This fixes printing Error objects in Chrome DevTools.
I've observed that Chrome DevTools is not source mapping and linkifying
URLs, when was running this on larger apps. Chrome DevTools talks to V8
via Chrome DevTools protocol, every object has a corresponding
[`RemoteObject`](https://chromedevtools.github.io/devtools-protocol/tot/Runtime/#type-RemoteObject).
When Chrome DevTools sees that Error object is printed in the console,
it will try to prettify it. `description` field of the corresponding
`RemoteObject` for the `Error` JavaScript object is a combination of
`Error` `name`, `message`, `stack` fields. This is not just a raw
`stack` field, so our prefix for this field just doesn't work. [V8 is
actually filtering out first line of the `stack` field, it only keeps
the stack frames as a string, and then this gets prefixed by `name` and
`message` fields, if they are
available](https://source.chromium.org/chromium/chromium/src/+/main:v8/src/inspector/value-mirror.cc;l=252-311;drc=bdc48d1b1312cc40c00282efb1c9c5f41dcdca9a?fbclid=IwZXh0bgNhZW0CMTEAAR1tMm5YC4jqowObad1qXFT98X4RO76CMkCGNSxZ8rVsg6k2RrdvkVFL0i4_aem_e2fRrqotKdkYIeWlJnk0RA).
As an illustration, this:
```
const fakeError = new Error('');
fakeError.name = 'Stack';
fakeError.stack = 'Error Stack:' + stack;
```
will be formatted by `V8` as this `RemoteObject`:
```
{
...
description: 'Stack: ...',
...
}
```
Notice that there is no `Error` prefix, that was previously added.
Because of this, [Chrome DevTools won't even try to symbolicate the
stack](ee4729d2cc/front_end/panels/console/ErrorStackParser.ts (L33-L35)),
because it doesn't have such prefix.
This flag will be used to gate a new timeline profiler that's integrate
with the Performance Tab and the new performance.measure extensions in
Chrome.
It replaces the existing DevTools feature so this disables
enableSchedulingProfiler when it is enabled since they can interplay in
weird ways potentially.
This means that experimental React now disable scheduling profiler and
enables this new approach.
The current state is that `rendererInterface`, which contains all the
backend logic, like generating component stack or attaching errors to
fibers, or traversing the Fiber tree, ..., is only mounted after the
Frontend is created.
For browser extension, this means that we don't patch console or track
errors and warnings before Chrome DevTools is opened.
With these changes, `rendererInterface` is created right after
`renderer` is injected from React via global hook object (e. g.
`__REACT_DEVTOOLS_GLOBAL_HOOK__.inject(...)`.
Because of the current implementation, in case of multiple Reacts on the
page, all of them will patch the console independently. This will be
fixed in one of the next PRs, where I am moving console patching to the
global Hook.
This change of course makes `hook.js` script bigger, but I think it is a
reasonable trade-off for better DevX. We later can add more heuristics
to optimize the performance (if necessary) of `rendererInterface` for
cases when Frontend was connected late and Backend is attempting to
flush out too many recorded operations.
This essentially reverts https://github.com/facebook/react/pull/26563.
When a component suspends and is replaced by a fallback, we should start
prerendering the fallback immediately, even before any new data is
received. During the retry, we can enter prerender mode directly if
we're sure that no new data was received since we last attempted to
render the boundary.
To do this, when completing the fallback, we leave behind a pending
retry lane on the Suspense boundary. Previously we only did this once a
promise resolved, but by assigning a lane during the complete phase, we
will know that there's speculative work to be done.
Then, upon committing the fallback, we mark the retry lane as suspended
— but only if nothing was pinged or updated in the meantime. That allows
us to immediately enter prerender mode (i.e. render without skipping any
siblings) when performing the retry.
Both for browser extension, and for React Native (as part of
`react-devtools-core`) `Store` is initialized before the Backend (and
`Agent` as a part of it):
bac33d1f82/packages/react-devtools-extensions/src/main/index.js (L111-L113)
Any messages that we send from `Store`'s constructor are ignored,
because there is nothing on the other end yet. With these changes,
`Agent` will send `backendInitialized` message to `Store`, after which
`getBackendVersion` and other events will be sent.
Note that `isBackendStorageAPISupported` and `isSynchronousXHRSupported`
are still sent from `Agent`'s constructor, because we don't explicitly
ask for it from `Store`, but these are used.
This the pre-requisite for fetching settings and unsupported renderers
reliably from the Frontend.
Make `onErrorOrWarning` and `getComponentStack` part of
`rendererInterface`. By doing this, they will be available from the
global hook `rendererInterfaces` Map. This makes them available to be
used by Hook, which soon will be the only one who is doing console
patching.
This is also a pre-requisite for removing `registerRenderer`:
d160aa0fbb/packages/react-devtools-shared/src/backend/console.js (L113-L121)
This adds owner stacks to replayed Server Component logs in environments
that don't support native console.createTask.
<img width="521" alt="Screenshot 2024-09-09 at 8 55 21 PM"
src="https://github.com/user-attachments/assets/261cfaee-ea65-4044-abf0-c41abf358fea">
It also tracks the logs in the global componentInfoToComponentLogsMap
which lets us associate those logs with Server Components when they
later commit into the fiber tree.
<img width="1280" alt="Screenshot 2024-09-09 at 9 31 16 PM"
src="https://github.com/user-attachments/assets/436312a6-f9f4-4add-8129-0fb9b9eb18ee">
I tried to create unit tests for this since it's now wired up
end-to-end. Unfortunately, the complicated testing set up for Flight
requires a complex set of resetting modules which are incompatible with
the complicated test setup in getVersionedRenderImplementation for
DevTools tests.
This reverts #19603.
Before:
<img width="724" alt="Screenshot 2024-08-28 at 12 07 29 AM"
src="https://github.com/user-attachments/assets/0613088f-c013-4f1c-92c3-fbdae8c1f109">
After:
<img width="771" alt="Screenshot 2024-08-28 at 12 08 13 AM"
src="https://github.com/user-attachments/assets/eef21bee-d11f-4f0a-9147-053a163f720f">
Consensus seems to be that while the purple on is a bit clearer and
easier to read. The purple is not on brand so it doesn't look like
React. It looks ugly. It's distracting (too eye catching). Taking away
attention from other tabs in an unfair way.
It also gets worse with more tabs added. We plan on both adding another
tab and panes inside other tabs (elements/sources) soon. Each needs to
be marked somehow as part of React but spelling it out is too long.
Putting inside a second tab means two clicks and takes away real-estate
from our extension and doesn't solve the problem with extension panes in
other tabs. We also plan on adding multiple different tracks to the
Performance tab which also needs a name other than just React and
spelling out React as a prefix is too long. The Emoji is too
distracting. So it seems best to uniformly apply the symbol - albeit it
might just look like a dot to many.
Dark mode looks close to on brand:
<img width="1089" alt="Screenshot 2024-08-28 at 12 32 50 AM"
src="https://github.com/user-attachments/assets/7175a540-4241-4c26-9e4d-4d367873af57">
The console instrumentation should not know about things like Fibers.
Only the renderer bindings should know about that stuff. We can improve
the layering by just moving all that stuff behind a `getComponentStack`
helper that gets injected by the renderer.
This sets us up for the Flight renderer #30906 to have its own
implementation of this function.
Stacked on #30899.
This adds another map to store Server Components logs. When they're
replayed with an owner we can associate them with a DevToolsInstance.
The replaying should happen before they can mount in Fiber so they'll
always have all logs when they mount. There can be more than one
Instance associated with any particular ReactComponentInfo. It can also
be unmounted and restored later.
One thing that's interesting about these is that when a Server Component
tree refreshes a new set of ReactComponentInfo will update through the
tree and the VirtualInstances will update with new instances. This means
that the old errors/warnings are no longer associated with the
VirtualInstance. I.e. it's not continually appended like updates do for
Fiber backed instances. On the client we dedupe errors/warnings for the
life time of the page. On the server that doesn't work well because it
would mean that when you refresh the page, you miss out on warnings so
we dedupe them per request instead. If we just appended on refresh it
would keep adding them.
If ever add a deduping mechanism that spans longer than a request, we
might need to do more of a merge when these updates.
Nothing actually adds logs to this map yet. That will need an
integration with Flight in a follow up.
This represents a virtual renderer that connects to the Flight Client.
It's virtual in the sense that the actual rendering has already happened
on the server. The Flight Client parses the result. Most of the result
then end up in objects that render into another renderer and that's how
we see most Server Components in DevTools. As part of the client's tree.
However, some things are side-effects that don't really connect to any
particular client renderer. For example preloads() and logs. For those
we need to treat the Flight Client as if it was its own renderer just
like a Fiber renderer or even legacy renderer. We really could support
Fizz and Flight Server as DevTools targets too for example to connect it
to the backend but there's just not much demand for that.
This will initially only be used to track the owners of replayed console
logs but could be expanded to more. For example to send controls to
start profiling on the server. It could also be expanded to build an RSC
payload inspector that is automatically connected.
We can simplify this tracking by not having a separate pending set of
logs and the logs tracked per instance and instead we just track the
logs per Fiber. This avoids the need to move it back into the pending
set after unmounts in case a Fiber is reparented.
The main motivation for this is to unify with an upcoming tracking of
logs for Server Components. For those it doesn't make sense to move them
into a per instance set and because the same Server Component - and its
logs - may appear more than once. So no particular instance should steal
it.
The second part of this change is that instead of looking up the
instance from fiber, which requires the fiberToFiberInstanceMap, we
instead look up if a component has any new logs when we traverse it in
the commit phase. After all for a component to have had a log it must
have updated. This is a similar technique to #30897. This technique also
works for Server Components without having to maintain a one to many
relationship from ComponentInfo to VirtualInstance. So it unifies them.
Normally this look up would be fast since the `fiberToComponentsLogs`
set would be empty and so doesn't add any significant weight to the
commit phase. If there's a ton of logs on many different components then
it's not great since it would slow down the commit phase but that's not
what we expect to see so in typical usage, this is better.
There is an unfortunate consequence though which is that
`console.warn/error` in passive effects (i.e. `useEffect`) wouldn't be
picked up because currently we traverse the logs in
`handleCommitFiberRoot` which is too early. If we moved that to
`handlePostCommitFiberRoot` this wouldn't be a problem. In the meantime,
I just detect this and do a brute force flush by walking all mounted
instances if there's a `console.warn/error` inside a passive effect.
If we ever add "owners" to event handlers that are triggered outside the
render/commit phases (like `<div onClick={...}>`) and we want to
associate error/warnings in those, we'd need a different technique to
ensure those get flushed in time.
## Summary
This PR bumps Flow all the way to the latest 0.245.2.
Most of the suppressions comes from Flow v0.239.0's change to include
undefined in the return of `Array.pop`.
I also enabled `react.custom_jsx_typing=true` and added custom jsx
typing to match the old behavior that `React.createElement` is
effectively any typed. This is necessary since various builtin
components like `React.Fragment` is actually symbol in the React repo
instead of `React.AbstractComponent<...>`. It can be made more accurate
by customizing the `React$CustomJSXFactory` type, but I will leave it to
the React team to decide.
## How did you test this change?
`yarn flow` for all the renderers
Stacked on #30896.
The problem with the `getUpdatersList` function is that it iterates over
Fibers and then looks up each of those Fibers in the
fiberToFiberInstanceMap which we ideally could get rid of.
However, every time an updater comes into play for a commit it must mean
that something below the updater itself updated and so the updater will
also be cloned which means we'll pass it on the way down when traversing
the tree in the commit.
When we do this traversal, we can just look if the Fiber is in the
updater set and if so add it to the updater list as we go.
When Context change tracking was added to support modern Context it
relied on the "memoizedValue" to read the current value. This only works
in React 18+ when it was added to support Lazy Context Propagation.
However, the backend stored the old value the same way it used to work
for legacy Context in a global map. This was unnecessary since we *also*
have the old value on the previous Fiber.
This removes all the costly tracking of previous values for every Fiber
that uses Contexts slowing down profiling. Instead, we just compare the
Contexts from
The downside is that this no longer supports detecting changes due to
legacy Context because it doesn't have a similar "previous" value.
However, legacy Context has long been deprecated and is completely
removed in 19. So I don't think it's worth supporting since you have to
be on an old version *and* actually use legacy Context *and* trying to
profile something that updates it. Which btw, updating legacy contexts
only worked at all from 16 something when we made updates work. So it
was unusual even in the slight gap where you could and before you had
migrated to modern Context introduced in 16.3.
Ideally we shouldn't use the `.alternate` to access previous state
because ideally Fibers shouldn't have alternates.
The only case it's ok to use it is when it is used to identity the
stateful part of a component's identity. In a non-alternate Fiber model
there would instead be another object that represents instance but in
the current model it's modeled by the pair.
It's not ok is to get the previous state of the tree since that would
not live on the stateful part.
We don't generally need this though because we have the previous state
on instance.data before updating it, or passed from above.
While looking at the Context tracking implementation for other reasons I
noticed this bug.
Originally it wasn't allowed to have conditional `useContext(context)`
(although we did because it's technically possible). With `use(context)`
it is officially allowed to be conditional as long as it is within a
Hook/Component and not within a try/catch.
This means that this loop comparing previous and next contexts need to
consider that the Context objects might not line up and so it's possibly
comparing apples to oranges. We already bailed if one was longer than
the other.
If the order of contexts changes later in the component that means
something else must have already changed earlier so the reason for the
rerender isn't the context so we can just return false in that case.
