This PR reorganizes the `react-dom` entrypoint to only pull in code that
is environment agnostic. Previously if you required anything from this
entrypoint in any environment the entire client reconciler was loaded.
In a prior release we added a server rendering stub which you could
alias in server environments to omit this unecessary code. After landing
this change this entrypoint should not load any environment specific
code.
While a few APIs are truly client (browser) only such as createRoot and
hydrateRoot many of the APIs you import from this package are only
useful in the browser but could concievably be imported in shared code
(components running in Fizz or shared components as part of an RSC app).
To avoid making these require opting into the client bundle we are
keeping them in the `react-dom` entrypoint and changing their
implementation so that in environments where they are not particularly
useful they do something benign and expected.
#### Removed APIs
The following APIs are being removed in the next major. Largely they
have all been deprecated already and are part of legacy rendering modes
where concurrent features of React are not available
* `render`
* `hydrate`
* `findDOMNode`
* `unmountComponentAtNode`
* `unstable_createEventHandle`
* `unstable_renderSubtreeIntoContainer`
* `unstable_runWithPrioirty`
#### moved Client APIs
These APIs were available on both `react-dom` (with a warning) and
`react-dom/client`. After this change they are only available on
`react-dom/client`
* `createRoot`
* `hydrateRoot`
#### retained APIs
These APIs still exist on the `react-dom` entrypoint but have normalized
behavior depending on which renderers are currently in scope
* `flushSync`: will execute the function (if provided) inside the
flushSync implemention of FlightServer, Fizz, and Fiber DOM renderers.
* `unstable_batchedUpdates`: This is a noop in concurrent mode because
it is now the only supported behavior because there is no legacy
rendering mode
* `createPortal`: This just produces an object. It can be called from
anywhere but since you will probably not have a handle on a DOM node to
pass to it it will likely warn in environments other than the browser
* preloading APIS such as `preload`: These methods will execute the
preload across all renderers currently in scope. Since we resolve the
Request object on the server using AsyncLocalStorage or the current
function stack in practice only one renderer should act upon the
preload.
In addition to these changes the server rendering stub now just rexports
everything from `react-dom`. In a future minor we will add a warning
when using the stub and in the next major we will remove the stub
altogether
We have changed the shape (and the runtime) of React Elements. To help
avoid precompiled or inlined JSX having subtle breakages or deopting
hidden classes, I renamed the symbol so that we can early error if
private implementation details are used or mismatching versions are
used.
Why "transitional"? Well, because this is not the last time we'll change
the shape. This is just a stepping stone to removing the `ref` field on
the elements in the next version so we'll likely have to do it again.
Follow up to #28783 and #28786.
Since we've changed the implementations of these we can rename them to
something a bit more descriptive while we're at it, since anyone
depending on them will need to upgrade their code anyway.
"react" with no condition:
`__CLIENT_INTERNALS_DO_NOT_USE_OR_WARN_USERS_THEY_CANNOT_UPGRADE`
"react" with "react-server" condition:
`__SERVER_INTERNALS_DO_NOT_USE_OR_WARN_USERS_THEY_CANNOT_UPGRADE`
"react-dom":
`__DOM_INTERNALS_DO_NOT_USE_OR_WARN_USERS_THEY_CANNOT_UPGRADE`
This implements the concept of a DEV-only "owner" for Server Components.
The owner concept isn't really super useful. We barely use it anymore,
but we do have it as a concept in DevTools in a couple of cases so this
adds it for parity. However, this is mainly interesting because it could
be used to wire up future owner-based stacks.
I do this by outlining the DebugInfo for a Server Component
(ReactComponentInfo). Then I just rely on Flight deduping to refer to
that. I refer to the same thing by referential equality so that we can
associate a Server Component parent in DebugInfo with an owner.
If you suspend and replay a Server Component, we have to restore the
same owner. To do that, I did a little ugly hack and stashed it on the
thenable state object. Felt unnecessarily complicated to add a stateful
wrapper for this one dev-only case.
The owner could really be anything since it could be coming from a
different implementation. Because this is the first time we have an
owner other than Fiber, I have to fix up a bunch of places that assumes
Fiber. I mainly did the `typeof owner.tag === 'number'` to assume it's a
Fiber for now.
This also doesn't actually add it to DevTools / RN Inspector yet. I just
ignore them there for now.
Because Server Components can be async the owner isn't tracked after an
await. We need per-component AsyncLocalStorage for that. This can be
done in a follow up.
## Summary
Based on
- https://github.com/facebook/react/pull/27903
This PR
- Silence warning in React tests
- Turn on flag
We want to finish cleaning up internal RTR usage, but let's prioritize
the deprecation process. We do this by silencing the internal warning
for now.
## How did you test this change?
`yarn build`
`yarn test ReactHooksInspectionIntegration -b`
## Overview
The error messages that say:
> ReactDOM.hydrate is no longer supported in React 18
Don't make sense in the React 19 release. Instead, they should say:
> ReactDOM.hydrate was removed in React 19.
For legacy mode, they should say:
> ReactDOM.hydrate has not been supported since React 18.
Reverting some of https://github.com/facebook/react/pull/27804 which
renamed this option to stable. This PR just replaces internal usage to
make upcoming PRs cleaner.
Keeping isConcurrent unstable for the next major release in order to
enable a broader deprecation of RTR and be consistent with concurrent
rendering everywhere for next major.
(https://github.com/facebook/react/pull/28498)
- Next major will use concurrent root
- The old behavior (legacy root by default, concurrent root with
unstable option) will be preserved for React Native until new
architecture is fully shipped.
- Flag and legacy root usage can be removed after RN dependency is
unblocked without an additional breaking change
We broke the ability to "break on uncaught exceptions" by adding a
try/catch higher up in the scheduling. We're giving up on fixing that so
we can remove the replay trick inside an event handler.
The issue with that approach is that we end up double logging a lot of
errors in DEV since they get reported to the page.
It's also a lot of complexity around this feature.
`_debugSource` was removed in
https://github.com/facebook/react/pull/28265.
This PR migrates DevTools to define `source` for Fiber based on
component stacks. This will be done lazily for inspected elements, once
user clicks on the element in the tree.
`DevToolsComponentStackFrame.js` was just copy-pasted from the
implementation in `ReactComponentStackFrame`.
Symbolication part is done in
https://github.com/facebook/react/pull/28471 and stacked on this commit.
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.
I'm a bit ambivalent about this one because it's not the main strategy
that I plan on pursuing. I plan on replacing most DEV-only specific
stacks like `console.error` stacks with a new take on owner stacks and
native stacks. The future owner stacks may or may not be exposed to
error boundaries in DEV but if they are they'd be a new errorInfo
property since they're owner based and not available in prod.
The use case in `console.error` mostly goes away in the future so this
PR is mainly for error boundaries. It doesn't hurt to have it in there
while I'm working on the better stacks though.
The `componentStack` property exposed to error boundaries is more like
production behavior similar to `new Error().stack` (which even in DEV
won't ever expose owner stacks because `console.createTask` doesn't
affect these). I'm not sure it's worth adding server components in DEV
(this PR) because then you have forked behavior between dev and prod.
However, since even in the future there won't be any other place to get
the *parent* stack, maybe this can be useful information even if it's
only dev. We could expose a third property on errorInfo that's DEV only
and parent stack but including server components. That doesn't seem
worth it over just having the stack differ in dev and prod.
I don't plan on adding line/column number to these particular stacks.
A follow up could be to add this to Fizz prerender too but only in DEV.
Depends on:
- #28317
- #28320
---
Changes the behavior of the JSX runtime to pass through `ref` as a
normal prop, rather than plucking it from the props object and storing
on the element.
This is a breaking change since it changes the type of the receiving
component. However, most code is unaffected since it's unlikely that a
component would have attempted to access a `ref` prop, since it was not
possible to get a reference to one.
`forwardRef` _will_ still pluck `ref` from the props object, though,
since it's extremely common for users to spread the props object onto
the inner component and pass `ref` as a differently named prop. This is
for maximum compatibility with existing code — the real impact of this
change is that `forwardRef` is no longer required.
Currently, refs are resolved during child reconciliation and stored on
the fiber. As a result of this change, we can move ref resolution to
happen only much later, and only for components that actually use them.
Then we can remove the `ref` field from the Fiber type. I have not yet
done that in this step, though.
Depends on:
- #28317
---
There's a ton of overlap between the createElement implementation and
the JSX implementation, so I combined them into a single module.
In the actual build output, the shared code between JSX and
createElement will get duplicated anyway, because react/jsx-runtime and
react (where createElement lives) are separate, flat build artifacts.
So this is more about code organization — with a few key exceptions, the
implementations of createElement and jsx are highly coupled.
Alternative to #28295.
Instead of stashing all of the Usables eagerly, we can extract them by
replaying the render when we need them like we do with any other hook.
We already had an implementation of `use()` but it wasn't quite
complete.
These can also include further DebugInfo on them such as what Server
Component rendered the Promise or async debug info. This is nice just to
see which use() calls were made in the side-panel but it can also be
used to gather everything that might have suspended.
Together with https://github.com/facebook/react/pull/28286 we cover the
case when a Promise was used a child and if it was unwrapped with use().
Notably we don't cover a Promise that was thrown (although we do support
that in a Server Component which maybe we shouldn't). Throwing a Promise
isn't officially supported though and that use case should move to the
use() Hook.
The pattern of conditionally suspending based on cache also isn't really
supported with the use() pattern. You should always call use() if you
previously called use() with the same input. This also ensures that we
can track what might have suspended rather than what actually did.
One limitation of this strategy is that it's hard to find all the places
something might suspend in a tree without rerendering all the fibers
again. So we might need to still add something to the tree to indicate
which Fibers may have further debug info / thenables.
Along with all the places using it like the `_debugSource` on Fiber.
This still lets them be passed into `createElement` (and JSX dev
runtime) since those can still be used in existing already compiled code
and we don't want that to start spreading to DOM attributes.
We used to have a DEV mode that compiles the source location of JSX into
the compiled output. This was nice because we could get the actual call
site of the JSX (instead of just somewhere in the component). It had a
bunch of issues though:
- It only works with JSX.
- The way this source location is compiled is different in all the
pipelines along the way. It relies on this transform being first and the
source location we want to extract but it doesn't get preserved along
source maps and don't have a way to be connected to the source hosted by
the source maps. Ideally it should just use the mechanism other source
maps use.
- Since it's expensive it only works in DEV so if it's used for
component stacks it would vary between dev and prod.
- It only captures the callsite of the JSX and not the stack between the
component and that callsite. In the happy case it's in the component but
not always.
Instead, we have another zero-cost trick to extract the call site of
each component lazily only if it's needed. This ensures that component
stacks are the same in DEV and PROD. At the cost of worse line number
information.
The better way to get the JSX call site would be to get it from `new
Error()` or `console.createTask()` inside the JSX runtime which can
capture the whole stack in a consistent way with other source mappings.
We might explore that in the future.
This removes source location info from React DevTools and React Native
Inspector. The "jump to source code" feature or inspection can be made
lazy instead by invoking the lazy component stack frame generation. That
way it can be made to work in prod too. The filtering based on file path
is a bit trickier.
When redesigned this UI should ideally also account for more than one
stack frame.
With this change the DEV only Babel transforms are effectively
deprecated since they're not necessary for anything.
Adding getter-functions for renderer implementations, which can be used
for jest tests. If we are testing against React with version < 18, we
are going to use legacy rendering, otherwise the concurrent one.
- Moving `act` implementation to a single getter-function, which is
based on React version we are testing RDT against.
- Removing unused mocks for `act`, which were designed for legacy
versions of React, validated with running tests against React 16 build.
