* Use identifierPrefix to avoid conflicts within the same response
identifierPrefix as an option exists to avoid useOpaqueIdentifier conflicting
when different renders are used within one HTML response.
This lets this be configured for the DOM renderer specifically since it's DOM
specific whether they will conflict across trees or not.
* Add test for using multiple containers in one HTML document
Some legacy environments can not encode non-strings. Those would specify
both as strings. They'll throw for binary data.
Some environments have to encode strings (like web streams). Those would
encode both as uint8array.
Some environments (like Node) can do either. It can be beneficial to leave
things as strings in case the native stream can do something smart with it.
* Move DOM/Native format configs to their respective packages
The streaming configs (Node/Browser) are different because they operate at
another dimension that exists in each package.
* Use escapeTextForBrowser to encode dynamic strings
We can now use local dependencies
* The exported '<React.StrictMode>' tag remains the same and opts legacy subtrees into strict mode level one ('mode == StrictModeL1'). This mode enables DEV-only double rendering, double component lifecycles, string ref warnings, legacy context warnings, etc. The primary purpose of this mode is to help detected render phase side effects. No new behavior. Roots created with experimental 'createRoot' and 'createBlockingRoot' APIs will also (for now) continue to default to strict mode level 1.
In a subsequent commit I will add support for a 'level' attribute on the '<React.StrictMode>' tag (as well as a new option supported by ). This will be the way to opt into strict mode level 2 ('mode == StrictModeL2'). This mode will enable DEV-only double invoking of effects on initial mount. This will simulate future Offscreen API semantics for trees being mounted, then hidden, and then shown again. The primary purpose of this mode is to enable applications to prepare for compatibility with the new Offscreen API (more information to follow shortly).
For now, this commit changes no public facing behavior. The only mechanism for opting into strict mode level 2 is the pre-existing 'enableDoubleInvokingEffects' feature flag (only enabled within Facebook for now).
* Renamed strict mode constants
StrictModeL1 -> StrictLegacyMode and StrictModeL2 -> StrictEffectsMode
* Renamed tests
* Split strict effects mode into two flags
One flag ('enableStrictEffects') enables strict mode level 2. It is similar to 'debugRenderPhaseSideEffectsForStrictMode' which enables srtict mode level 1.
The second flag ('createRootStrictEffectsByDefault') controls the default strict mode level for 'createRoot' trees. For now, all 'createRoot' trees remain level 1 by default. We will experiment with level 2 within Facebook.
This is a prerequisite for adding a configurable option to 'createRoot' that enables choosing a different StrictMode level than the default.
* Add StrictMode 'unstable_level' prop and createRoot 'unstable_strictModeLevel' option
New StrictMode 'unstable_level' prop allows specifying which level of strict mode to use. If no level attribute is specified, StrictLegacyMode will be used to maintain backwards compatibility. Otherwise the following is true:
* Level 0 does nothing
* Level 1 selects StrictLegacyMode
* Level 2 selects StrictEffectsMode (which includes StrictLegacyMode)
Levels can be increased with nesting (0 -> 1 -> 2) but not decreased.
This commit also adds a new 'unstable_strictModeLevel' option to the createRoot and createBatchedRoot APIs. This option can be used to override default behavior to increase or decrease the StrictMode level of the root.
A subsequent commit will add additional DEV warnings:
* If a nested StrictMode tag attempts to explicitly decrease the level
* If a level attribute changes in an update
With this change, if a node is a Fabric node, we route the setJSResponder call to FabricUIManager. Native counterpart is already landed. Tested internally as D26241364.
* Add `supportsMicrotasks` to the host config
Only certain renderers support scheduling a microtask, so we need a
renderer specific flag that we can toggle. That way it's off for some
renderers and on for others.
I copied the approach we use for the other optional parts of the host
config, like persistent mode and test selectors.
Why isn't the feature flag sufficient?
The feature flag modules, confusingly, are not renderer-specific, at
least when running the our tests against the source files. They are
meant to correspond to a release channel, not a renderer, but we got
confused at some point and haven't cleaned it up.
For example, when we run `yarn test`, Jest loads the flags from the
default `ReactFeatureFlags.js` module, even when we import the React
Native renderer — but in the actual builds, we load a different feature
flag module, `ReactFeatureFlags.native-oss.js.` There's no way in our
current Jest load a different host config for each renderer, because
they all just import the same module. We should solve this by creating
separate Jest project for each renderer, so that the flags loaded when
running against source are the same ones that we use in the
compiled bundles.
The feature flag (`enableDiscreteMicrotasks`) still exists — it's used
to set the React DOM host config's `supportsMicrotasks` flag to `true`.
(Same for React Noop) The important part is that turning on the feature
flag does *not* affect the other renderers, like React Native.
The host config will likely outlive the feature flag, too, since the
feature flag only exists so we can gradually roll it out and measure the
impact in production; once we do, we'll remove it. Whereas the host
config flag may continue to be used to disable the discrete microtask
behavior for RN, because RN will likely use a native (non-JavaScript)
API to schedule its tasks.
* Add `supportsMicrotask` to react-reconciler README
* Add the feature flag
* Add a host config method
* Wire it up to the work loop
* Export constants for third-party renderers
* Document for third-party renderers
* RN: Implement `sendAccessibilityEvent` on HostComponent
Implement `sendAccessibilityEvent` on HostComponent for Fabric and non-Fabric RN.
Currently the Fabric version is a noop and non-Fabric uses
AccessibilityInfo directly. The Fabric version will be updated once
native Fabric Android/iOS support this method in the native UIManager.
* Move methods out of HostComponent
* Properly type dispatchCommand and sendAccessibilityEvent handle arg
* Implement Fabric side of sendAccessibilityEvent
* Add tests: 1. Fabric->Fabric, 2. Paper->Fabric, 3. Fabric->Paper, 4. Paper->Paper
* Fix typo: ReactFaricEventTouch -> ReactFabricEventTouch
* fix flow types
* prettier
There is a worry that `useOpaqueIdentifier` might run out of unique IDs if running for long enough. This PR moves the unique ID counter so it's generated per server renderer object instead. For people who render different subtrees, this PR adds a prefix option to `renderToString`, `renderToStaticMarkup`, `renderToNodeStream`, and `renderToStaticNodeStream` so identifiers can be differentiated for each individual subtree.
Adds several new experimental APIs to aid with automated testing.
Each of the methods below accepts an array of "selectors" that identifies a path (or paths) through a React tree. There are four basic selector types:
* Component: Matches Fibers with the specified React component type
* Role: Matches Host Instances matching the (explicit or implicit) accessibility role.
* Test name: Matches Host Instances with a data-testname attribute.
* Text: Matches Host Instances that directly contain the specified text.
* There is also a special lookahead selector type that enables further matching within a path (without actually including the path in the result). This selector type was inspired by the :has() CSS pseudo-class. It enables e.g. matching a <section> that contained a specific header text, then finding a like button within that <section>.
API
* findAllNodes(): Finds all Host Instances (e.g. HTMLElement) within a host subtree that match the specified selector criteria.
* getFindAllNodesFailureDescription(): Returns an error string describing the matched and unmatched portions of the selector query.
* findBoundingRects(): For all React components within a host subtree that match the specified selector criteria, return a set of bounding boxes that covers the bounds of the nearest (shallowed) Host Instances within those trees.
* observeVisibleRects(): For all React components within a host subtree that match the specified selector criteria, observe if it’s bounding rect is visible in the viewport and is not occluded.
* focusWithin(): For all React components within a host subtree that match the specified selector criteria, set focus within the first focusable Host Instance (as if you started before this component in the tree and moved focus forwards one step).
* Root API should clear non-empty roots before mounting
Legacy render-into-subtree API removes children from a container before rendering into it. The root API did not do this previously, but just left the children around in the document.
This commit adds a new FiberRoot flag to clear a container's contents before mounting. This is done during the commit phase, to avoid multiple, observable mutations.
* Implement component stack extraction hack
* Normalize errors in tests
This drops the requirement to include owner to pass the test.
* Special case tests
* Add destructuring to force toObject which throws before the side-effects
This ensures that we don't double call yieldValue or advanceTime in tests.
Ideally we could use empty destructuring but ES lint doesn't like it.
* Cache the result in DEV
In DEV it's somewhat likely that we'll see many logs that add component
stacks. This could be slow so we cache the results of previous components.
* Fixture
* Add Reflect to lint
* Log if out of range.
* Fix special case when the function call throws in V8
In V8 we need to ignore the first line. Normally we would never get there
because the stacks would differ before that, but the stacks are the same if
we end up throwing at the same place as the control.
Some of our internal reconciler types have leaked into other packages.
Usually, these types are treated as opaque; we don't read and write
to its fields. This is good.
However, the type is often passed back to a reconciler method. For
example, React DOM creates a FiberRoot with `createContainer`, then
passes that root to `updateContainer`. It doesn't do anything with the
root except pass it through, but because `updateContainer` expects a
full FiberRoot, React DOM is still coupled to all its fields.
I don't know if there's an idiomatic way to handle this in Flow. Opaque
types are simlar, but those only work within a single file. AFAIK,
there's no way to use a package as the boundary for opaqueness.
The immediate problem this presents is that the reconciler refactor will
involve changes to our internal data structures. I don't want to have to
fork every single package that happens to pass through a Fiber or
FiberRoot, or access any one of its fields. So my current plan is to
share the same Flow type across both forks. The shared type will be a
superset of each implementation's type, e.g. Fiber will have both an
`expirationTime` field and a `lanes` field. The implementations will
diverge, but not the types.
To do this, I lifted the type definitions into a separate module.
* Add useOpaqueIdentifier Hook
We currently use unique IDs in a lot of places. Examples are:
* `<label for="ID">`
* `aria-labelledby`
This can cause some issues:
1. If we server side render and then hydrate, this could cause an
hydration ID mismatch
2. If we server side render one part of the page and client side
render another part of the page, the ID for one part could be
different than the ID for another part even though they are
supposed to be the same
3. If we conditionally render something with an ID , this might also
cause an ID mismatch because the ID will be different on other
parts of the page
This PR creates a new hook `useUniqueId` that generates a different
unique ID based on whether the hook was called on the server or client.
If the hook is called during hydration, it generates an opaque object
that will rerender the hook so that the IDs match.
Co-authored-by: Andrew Clark <git@andrewclark.io>
* Add feature flag
* Split stack from current fiber
You can get stack from any fiber, not just current.
* Refactor description of component frames
These should use fiber tags for switching. This also puts the relevant code
behind DEV flags.
* We no longer expose StrictMode in component stacks
They're not super useful and will go away later anyway.
* Update tests
Context is no longer part of SSR stacks. This was already the case on the
client.
forwardRef no longer is wrapped on the stack. It's still in getComponentName
but it's probably just noise in stacks. Eventually we'll remove the wrapper
so it'll go away anyway. If we use native stack frames they won't have this
extra wrapper.
It also doesn't pick up displayName from the outer wrapper. We could maybe
transfer it but this will also be fixed by removing the wrapper.
* Forward displayName onto the inner function for forwardRef and memo in DEV
This allows them to show up in stack traces.
I'm not doing this for lazy because lazy is supposed to be called on the
consuming side so you shouldn't assign it a name on that end. Especially
not one that mutates the inner.
* Use multiple instances of the fake component
We mutate the inner component for its name so we need multiple copies.
* Enable prefer-const rule
Stylistically I don't like this but Closure Compiler takes advantage of
this information.
* Auto-fix lints
* Manually fix the remaining callsites
Sebastian Markbåge
Timothy Yung
Joshua Gross
Brian Vaughn
Rubén Norte
Valentin Shergin
Andrew Clark
Dan Abramov
Ricky
Dominic Gannaway
Bhumij Gupta
CY Lim
Luna Ruan