## Summary
Experimentation has completed for this at Meta and we've observed
positive impact on key React Native surfaces.
## How did you test this change?
yarn flow fabric
## Summary
ReactNativeAttributePayloadFabric was synced to react-native in
https://github.com/facebook/react-native/commit/0e42d33cbcfadcf5d787108da785d56a83d07a9f.
We should now consume these methods from the
ReactNativePrivateInterface.
Moving these methods to the React Native repo gives us more flexibility
to experiment with new techniques for bridging and diffing props
payloads.
I did have to leave some stub implementations for existing unit tests,
but moved all detailed tests to the React Native repo.
## How did you test this change?
* `yarn prettier`
* `yarn test ReactFabric-test`
## Summary
In react-native props that are passed as function get converted to a
boolean (`true`). This is the default pattern for event handlers in
react-native.
However, there are reasons for why you might want to opt-out of this
behavior, and instead, pass along the actual function as the prop.
Right now, there is no way to do this, and props that are functions
always get set to `true`.
The `ViewConfig` attributes already have the API for a `process`
function. I simply moved the check for the process function up, so if a
ViewConfig's prop attribute configured a process function this is always
called first.
This provides an API to opt out of the default behavior.
This is the accompanied PR for react-native:
- https://github.com/facebook/react-native/pull/48777
## 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.
-->
I modified the code manually in a template react-native app and
confirmed its working. This is a code path you only need in very special
cases, thus it's a bit hard to provide a test for this. I recorded a
video where you can see that the changes are active and the prop is
being passed as native value.
For this I created a custom native component with a view config that
looked like this:
```js
const viewConfig = {
uiViewClassName: 'CustomView',
bubblingEventTypes: {},
directEventTypes: {},
validAttributes: {
nativeProp: {
process: (nativeProp) => {
// Identity function that simply returns the prop function callback
// to opt out of this prop being set to `true` as its a function
return nativeProp
},
},
},
}
```
https://github.com/user-attachments/assets/493534b2-a508-4142-a760-0b1b24419e19
Additionally I made sure that this doesn't conflict with any existing
view configs in react native. In general, this shouldn't be a breaking
change, as for existing view configs it didn't made a difference if you
simply set `myProp: true` or `myProp: { process: () => {...} }` because
as soon as it was detected that the prop is a function the config
wouldn't be used (which is what this PR fixes).
Probably everyone, including the react-native core components use
`myProp: true` for callback props, so this change should be fine.
## Summary
We completed testing on these internally, so can cleanup the separate
fast and slow paths and remove the `enableShallowPropDiffing` flag which
we're not pursuing.
## How did you test this change?
```
yarn test ReactNativeAttributePayloadFabric
```
When a new child of a fragment instance is inserted, we need to notify
the instance to keep any relevant tracking up to date. For example, we
automatically observe the new child with any active
IntersectionObserver.
For mutable renderers (DOM), we reuse the existing traversal in
`commitPlacement` that does the insertions for HostComponents. Immutable
renderers (Fabric) exit this path before the traversal though, so
currently we can't notify the fragment instances.
Here I've created a separate traversal in `commitPlacement`,
specifically for immutable renders when `enableFragmentRefs` is on.
Adds Fragment Ref support to RN through the Fabric config, starting with
`observeUsing`/`unobserveUsing`. This is mostly a copy from the
implementation on DOM, and some of it can likely be shared in the future
but keeping it separate for now and we can refactor as we add more
features.
Added a basic test with Fabric, but testing specific methods requires so
much mocking that it doesn't seem valuable here.
I built Fabric and ran on the Catalyst app internally to test with
intersection observers end to end.
## Summary
The React Native Renderer exports a
`__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED` property with a
single method that has no remaining call sites:
`computeComponentStackForErrorReporting`
This PR cleans up this unused export.
## How did you test this change?
```
$ yarn
$ yarn flow fabric
$ yarn test
```
## Summary
As promised on https://github.com/facebook/react/pull/29627, this
creates a unit test for the `findNodeHandle` error that prevents
developers from calling it within render methods.
## How did you test this change?
```
$ yarn test ReactFabric-test.internal.js
```
Persistent renderers used the `Update` effect flag to check if a subtree
needs to be cloned. In some cases, that causes extra renders, such as
when a layout effect is triggered which only has an effect on the JS
side, but doesn't update the host components.
It's been a bit tricky to find the right places where this needs to be
set and I'm not 100% sure I got all the cases even though the tests
passed.
## Summary
This PR fixes the `fastAddProperties` function. Now it nullifies a prop
if it was defined in one of the items of a style array, but then set to
`undefined` or `null` in one of the subsequent items. E.g. `style:
[{top: 0}, {top: undefined}]` should evaluate to `{top: null}`. Also
added a test case for that.
## How did you test this change?
```
yarn test packages/react-native-renderer -r=xplat --variant=false
yarn test packages/react-native-renderer -r=xplat --variant=true
yarn flow native
```
For environments that still have legacy contexts available, this adds a
warning to make the remaining call sites easier to locate and encourage
upgrades.
The explicit mock override in this test was causing it to always run as
native-oss instead of also as xplat. This moves the test to use `//
@gate persistent` instead to run it in all persistent configs.
Basically make `console.error` and `console.warn` behave like normal -
when a component stack isn't appended. I need this because I need to be
able to print rich logs with the component stack option and to be able
to disable instrumentation completely in `console.createTask`
environments that don't need it.
Currently we can't print logs with richer objects because they're
toString:ed first. In practice, pretty much all arguments we log are
already toString:ed so it's not necessary anyway. Some might be like a
number. So it would only be a problem if some environment can't handle
proper consoles but then it's up to that environment to toString it
before logging.
The `Warning: ` prefix is historic and is both noisy and confusing. It's
mostly unnecessary since the UI surrounding `console.error` and
`console.warn` tend to have visual treatment around it anyway. However,
it's actively misleading when `console.error` gets prefixed with a
Warning that we consider an error level. There's an argument to be made
that some of our `console.error` don't make the bar for an error but
then the argument is to downgrade each of those to `console.warn` - not
to brand all our actual error logging with `Warning: `.
Apparently something needs to change in React Native before landing this
because it depends on the prefix somehow which probably doesn't make
sense already.
## Overview
Updates `eslint-plugin-jest` and enables the recommended rules with some
turned off that are unhelpful.
The main motivations is:
a) we have a few duplicated tests, which this found an I deleted
b) making sure we don't accidentally commit skipped tests
## Summary
We currently do deep diffing for object props, and also use custom
differs, if they are defined, for props with custom attribute config.
The idea is to simply do a `===` comparison instead of all that work. We
will do less computation on the JS side, but send more data to native.
The hypothesis is that this change should be neutral in terms of
performance. If that's the case, we'll be able to get rid of custom
differs, and be one step closer to deleting view configs.
This PR adds the `enableShallowPropDiffing` feature flag to support this
experiment.
## How did you test this change?
With `enableShallowPropDiffing` hardcoded to `true`:
```
yarn test packages/react-native-renderer
```
This fails on the following test cases:
- should use the diff attribute
- should do deep diffs of Objects by default
- should skip deeply-nested changed functions
Which makes sense with this change. These test cases should be deleted
if the experiment is shipped.
## Overview
We didn't have any tests that ran in persistent mode with the xplat
feature flags (for either variant).
As a result, invalid test gating like in
https://github.com/facebook/react/pull/29664 were not caught.
This PR adds test flavors for `ReactFeatureFlag-native-fb.js` in both
variants.
## Summary
This PR add tests for `ReactNativeAttributePayloadFabric.js`.
It introduces `ReactNativeAttributePayloadFabric-test.internal.js`,
which is a copy-paste of `ReactNativeAttributePayload-test.internal.js`.
On top of that, there is a bunch of new test cases for the
`ReactNativeAttributePayloadFabric.create` function.
## How did you test this change?
```
yarn test packages/react-native-renderer
```
## Summary
I'm looking at cleaning up some unnecessary manual property flattening
in React Native and wanted to verify this behaviour is working as
expected, where properties from nested objects will always overwrite
properties from the base object.
## How did you test this change?
Unit tests
Saves some bytes and ensures that we're actually disabling it.
Turns out this flag wasn't disabling React Native/Fabric, React Noop and
React ART legacy modes so those are updated too.
Should be rebased on #28681.
Stacked on top of #28498 for test fixes.
### Don't Rethrow
When we started React it was 1:1 setState calls a series of renders and
if they error, it errors where the setState was called. Simple. However,
then batching came and the error actually got thrown somewhere else.
With concurrent mode, it's not even possible to get setState itself to
throw anymore.
In fact, all APIs that can rethrow out of React are executed either at
the root of the scheduler or inside a DOM event handler.
If you throw inside a React.startTransition callback that's sync, then
that will bubble out of the startTransition but if you throw inside an
async callback or a useTransition we now need to handle it at the hook
site. So in 19 we need to make all React.startTransition swallow the
error (and report them to reportError).
The only one remaining that can throw is flushSync but it doesn't really
make sense for it to throw at the callsite neither because batching.
Just because something rendered in this flush doesn't mean it was
rendered due to what was just scheduled and doesn't mean that it should
abort any of the remaining code afterwards. setState is fire and forget.
It's send an instruction elsewhere, it's not part of the current
imperative code.
Error boundaries never rethrow. Since you should really always have
error boundaries, most of the time, it wouldn't rethrow anyway.
Rethrowing also actually currently drops errors on the floor since we
can only rethrow the first error, so to avoid that we'd need to call
reportError anyway. This happens in RN events.
The other issue with rethrowing is that it logs an extra console.error.
Since we're not sure that user code will actually log it anywhere we
still log it too just like we do with errors inside error boundaries
which leads all of these to log twice.
The goal of this PR is to never rethrow out of React instead, errors
outside of error boundaries get logged to reportError. Event system
errors too.
### Breaking Changes
The main thing this affects is testing where you want to inspect the
errors thrown. To make it easier to port, if you're inside `act` we
track the error into act in an aggregate error and then rethrow it at
the root of `act`. Unlike before though, if you flush synchronously
inside of act it'll still continue until the end of act before
rethrowing.
I expect most user code breakages would be to migrate from `flushSync`
to `act` if you assert on throwing.
However, in the React repo we also have `internalAct` and the
`waitForThrow` helpers. Since these have to use public production
implementations we track these using the global onerror or process
uncaughtException. Unlike regular act, includes both event handler
errors and onRecoverableError by default too. Not just render/commit
errors. So I had to account for that in our tests.
We restore logging an extra log for uncaught errors after the main log
with the component stack in it. We use `console.warn`. This is not yet
ignorable if you preventDefault to the main error event. To avoid
confusion if you don't end up logging the error to console I just added
`An error occurred`.
### Polyfill
All browsers we support really supports `reportError` but not all test
and server environments do, so I implemented a polyfill for browser and
node in `shared/reportGlobalError`. I don't love that this is included
in all builds and gets duplicated into isomorphic even though it's not
actually needed in production. Maybe in the future we can require a
polyfill for this.
### Follow Ups
In a follow up, I'll make caught vs uncaught error handling be
configurable too.
---------
Co-authored-by: Ricky Hanlon <rickhanlonii@gmail.com>
Updates useFormState to allow a sync function to be passed as an action.
A form action is almost always async, because it needs to talk to the
server. But since we support client-side actions, too, there's no reason
we can't allow sync actions, too.
I originally chose not to allow them to keep the implementation simpler
but it's not really that much more complicated because we already
support this for actions passed to startTransition. So now it's
consistent: anywhere an action is accepted, a sync client function is a
valid input.
## Summary
Currently when cloning nodes in Fabric, we reset a node's children on
each clone, and then repeatedly call appendChild to restore the previous
list of children (even if it was quasi-identical to before). This causes
unnecessary invalidation of the layout state in Fabric's ShadowNode data
(which in turn may require additional yoga clones) and extra JSI calls.
This PR adds a feature flag to pass in the children as part of the clone
call, so Fabric always has a complete view of the node that's being
mutated.
This feature flag requires matching changes in the react-native repo:
https://github.com/facebook/react-native/pull/39817
## How did you test this change?
Unit test added demonstrates the new behaviour
```
yarn test -r www-modern ReactFabric-test
yarn test ReactFabric-test.internal
```
Tested a manual sync into React Native and verified core surfaces render
correctly.
## Summary
This adds the ability to create public instances for text nodes in
Fabric. The implementation for the public instances lives in React
Native (as it does for host components after #26437). The logic here
just handles their lazy instantiation when requested via
`getPublicInstanceFromInternalInstanceHandle`, which is called by Fabric
with information coming from the shadow tree.
It's important that the creation of public instances for text nodes is
done lazily to avoid regressing memory usage when unused. Instances for
text nodes are left intact if the public instance is never accessed.
This is necessary to implement access to text nodes in React Native as
explained in
https://github.com/react-native-community/discussions-and-proposals/pull/607
## How did you test this change?
Added unit tests (also fixed a test that was only testing the logic in a
mock :S).
## Summary
Now that React Native owns the definition for public instances in Fabric
and ReactNativePrivateInterface provides the methods to create instances
and access private fields (see
https://github.com/facebook/react-native/pull/36570), we can remove the
definitions from React.
After this PR, React Native public instances will be opaque types for
React and it will only handle their creation but not their definition.
This will make RN similar to DOM in how public instances are handled.
This is a new version of #26418 which was closed without merging.
## How did you test this change?
* Existing tests.
* Manually synced the changes in this PR to React Native and tested it
end to end in Meta's infra.
## Summary
We are going to move the definition of public instances from React to
React Native to have them together with the native methods in Fabric
that they invoke. This will allow us to have a better type safety
between them and iterate faster on the implementation of this proposal:
https://github.com/react-native-community/discussions-and-proposals/pull/607
The interface between React and React Native would look like this after
this change and a following PR (#26418):
React → React Native:
```javascript
ReactNativePrivateInterface.createPublicInstance // to provide via refs
ReactNativePrivateInterface.getNodeFromPublicInstance // for DevTools, commands, etc.
ReactNativePrivateInterface.getNativeTagFromPublicInstance // to implement `findNodeHandle`
```
React Native → React (ReactFabric):
```javascript
ReactFabric.getNodeFromInternalInstanceHandle // to get most recent node to call into native
ReactFabric.getPublicInstanceFromInternalInstanceHandle // to get public instances from results from native
```
## How did you test this change?
Flow
Existing unit tests
## Summary
The current definition of `Instance` in Fabric has 2 fields:
- `node`: reference to the native node in the shadow tree.
- `canonical`: public instance provided to users via refs + some
internal fields needed by Fabric.
We're currently using `canonical` not only as the public instance, but
also to store internal properties that Fabric needs to access in
different parts of the codebase. Those properties are, in fact,
available through refs as well, which breaks encapsulation.
This PR splits that into 2 separate fields, leaving the definition of
instance as:
- `node`: reference to the native node in the shadow tree.
- `publicInstance`: public instance provided to users via refs.
- Rest of internal fields needed by Fabric at the instance level.
This also migrates all the current usages of `canonical` to use the
right property depending on the use case.
To improve encapsulation (and in preparation for the implementation of
this [proposal to bring some DOM APIs to public instances in React
Native](https://github.com/react-native-community/discussions-and-proposals/pull/607)),
this also **moves the creation of and the access to the public instance
to separate modules** (`ReactFabricPublicInstance` and
`ReactFabricPublicInstanceUtils`). In a following diff, that module will
be moved into the `react-native` repository and we'll access it through
`ReactNativePrivateInterface`.
## How did you test this change?
Existing unit tests.
Manually synced the PR in Meta infra and tested in Catalyst + the
integration with DevTools. Everything is working normally.
The www builds include disableLegacyContext as a dynamic flag, so we
should be running the tests in that mode, too. Previously we were
overriding the flag during the test run. This strategy usually doesn't
work because the flags get compiled out in the final build, but we
happen to not test www in build mode, only source.
To get of this hacky override, I added a test gate to every test that
uses legacy context. When we eventually remove legacy context from the
codebase, this should make it slightly easier to find which tests are
affected. And removes one more hack from our hack-ridden test config.
Given that sometimes www has features enabled that aren't on in other
builds, we might want to consider testing its build artifacts in CI,
rather than just source. That would have forced this cleanup to happen
sooner. Currently we only test the public builds in CI.
Prior to #26347, our internal `act` API (not the public API) behaved
differently depending on whether the scope function returned a promise
(i.e. was an async function), for historical reasons that no longer
apply. Now that this is fixed, I've codemodded all async act scopes that
don't contain an await to be sync.
No pressing motivation other than it looks nicer and the codemod was
easy. Might help avoid confusion for new contributors who see async act
scopes with nothing async inside and infer it must be like that for a
reason.
This is not a public API. We only use it for our internal tests, the
ones in this repo. Let's move it to this private package. Practically
speaking this will also let us use async/await in the implementation.
Similar to the rationale for `waitFor` (see #26285), we should always
await the result of an `act` call so that microtasks have a chance to
fire.
This only affects the internal `act` that we use in our repo, for now.
In the public `act` API, we don't yet require this; however, we
effectively will for any update that triggers suspense once `use` lands.
So we likely will start warning in an upcoming minor.
We're fixing the timing of layout and passive effects in React Native,
and adding support for some Web APIs so common use cases for those
effects can be implemented with the same code on React and React Native.
Let's take this example:
```javascript
function MyComponent(props) {
const viewRef = useRef();
useLayoutEffect(() => {
const rect = viewRef.current?.getBoundingClientRect();
console.log('My view is located at', rect?.toJSON());
}, []);
return <View ref={viewRef}>{props.children}</View>;
}
```
This could would work as expected on Web (ignoring the use of `View` and
assuming something like `div`) but not on React Native because:
1. Layout is done asynchronously in a background thread in parallel with
the execution of layout and passive effects. This is incorrect and it's
being fixed in React Native (see
https://github.com/facebook/react-native/commit/afec07aca273503b0647dbf1f73c518c6e52e8ba).
2. We don't have an API to access layout information synchronously. The
existing `ref.current.measureInWindow` uses callbacks to pass the
result. That is asynchronous at the moment in Paper (the legacy renderer
in React Native), but it's actually synchronous in Fabric (the new React
Native renderer).
This fixes point 2) by adding a Web-compatible method to access layout
information (on Fabric only).
This has 2 dependencies in React Native:
1. Access to `getBoundingClientRect` in Fabric, which was added in
https://github.com/facebook/react-native/blob/main/ReactCommon/react/renderer/uimanager/UIManagerBinding.cpp#L644-
L676
2. Access to `DOMRect`, which was added in
https://github.com/facebook/react-native/commit/673c7617bcf90a892a0afc2c0d9cf9c0493fdf27
.
As next step, I'll modify the implementation of this and other methods
in Fabric to warn when they're accessed during render. We can't do this
on Web because we can't (shouldn't) modify built-in DOM APIs, but we can
do it in React Native because the refs objects are built by the
framework.
## Summary
- yarn.lock diff +-6249, **small pr**
- use jest-environment-jsdom by default
- uncaught error from jsdom is an error object instead of strings
- abortSignal.reason is read-only in jsdom and node,
https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal/reason
## How did you test this change?
ci green
---------
Co-authored-by: Sebastian Silbermann <silbermann.sebastian@gmail.com>
The old version of prettier we were using didn't support the Flow syntax
to access properties in a type using `SomeType['prop']`. This updates
`prettier` and `rollup-plugin-prettier` to the latest versions.
I added the prettier config `arrowParens: "avoid"` to reduce the diff
size as the default has changed in Prettier 2.0. The largest amount of
changes comes from function expressions now having a space. This doesn't
have an option to preserve the old behavior, so we have to update this.
Revert https://github.com/facebook/react/commit/353c30252. The commit
breaks old React Native where `nativeFabricUIManager` is undefined. I
need to add unit test for this to make sure it doesn't happen in the
future and create a mechanism to deal with undefined
`nativeFabricUIManager`.
This is to unblock React sync to React Native.
Hermes parser is the preferred parser for Flow code going forward. We
need to upgrade to this parser to support new Flow syntax like function
`this` context type annotations or `ObjectType['prop']` syntax.
Unfortunately, there's quite a few upgrades here to make it work somehow
(dependencies between the changes)
- ~Upgrade `eslint` to `8.*`~ reverted this as the React eslint plugin
tests depend on the older version and there's a [yarn
bug](https://github.com/yarnpkg/yarn/issues/6285) that prevents
`devDependencies` and `peerDependencies` to different versions.
- Remove `eslint-config-fbjs` preset dependency and inline the rules,
imho this makes it a lot clearer what the rules are.
- Remove the turned off `jsx-a11y/*` rules and it's dependency instead
of inlining those from the `fbjs` config.
- Update parser and dependency from `babel-eslint` to `hermes-eslint`.
- `ft-flow/no-unused-expressions` rule replaces `no-unused-expressions`
which now allows standalone type asserts, e.g. `(foo: number);`
- Bunch of globals added to the eslint config
- Disabled `no-redeclare`, seems like the eslint upgrade started making
this more precise and warn against re-defined globals like
`__EXPERIMENTAL__` (in rollup scripts) or `fetch` (when importing fetch
from node-fetch).
- Minor lint fixes like duplicate keys in objects.
Add support for `setNativeProps` in Fabric to make migration to the new
architecture easier. The React Native part of this has already landed in
the core and iOS in
https://github.com/facebook/react-native/commit/1d3fa40c59b234f21f516db85c322ec0ed0311e0.
It is still recommended to move away from `setNativeProps` because the
API will not work with future features.
Calling any function on `nativeFabricUIManager`, for example
`nativeFabricUIManager.measure`, results in a round trip to the host
platform through jsi layer. It is the same for repeated calls to same
host function. This is unnecessary overload which can be avoided by
retaining host function in a variable.
* Facebook -> Meta in copyright
rg --files | xargs sed -i 's#Copyright (c) Facebook, Inc. and its affiliates.#Copyright (c) Meta Platforms, Inc. and affiliates.#g'
* Manual tweaks
This lets us share it with react-server-dom-webpack while still having a
dependency on react-dom. It also makes somewhat sense from a bundling
perspective since react-dom is an external to itself.
Ricky
Pieter De Baets
Hanno J. Gödecke
Jack Pope
Timothy Yung
Jan Kassens
Dmytro Rykun
Sebastian Markbåge
Sebastian Silbermann
Rubén Norte
Andrew Clark
Ming Ye
Rubén Norte
Samuel Susla