* Explicitly set highWaterMark to 0 for ReadableStreams
This is because not all streaming implementations respect the
default behavior of settings highWaterMark to 0 for byte streams.
Being explicit guarantees the intended behavior across runtimes.
* Remove size methods and add FlowFixMe instead
* use return from onError
* export getSuspenseInstanceFallbackError
* stringToChunk
* return string from onError in downstream type signatures
* 1 more type
* support encoding errors in html stream and escape user input
This commit adds another way to get errors to the suspense instance by encoding them as dataset properties of a template element at the head of the boundary. Previously if there was an error before the boundary flushed there was no way to stream the error to the client because there would never be a client render instruction.
Additionally the error is sent in 3 parts
1) error hash - this is always sent (dev or prod) if one is provided
2) error message - Dev only
3) error component stack - Dev only, this now captures the stack at the point of error
Another item addressed in this commit is the escaping of potentially unsafe data. all error components are escaped as test for browers when written into the html and as javascript strings when written into a client render instruction.
* nits
Co-authored-by: Marco Salazar <salazarm@fb.com>
* [Fizz] Improve text separator byte efficiency
Previously text separators were inserted following any Text node in Fizz. This increases bytes sent when streaming and in some cases such as title elements these separators are not interpreted as comment nodes and leak into the visual aspects of a page as escaped text.
The reason simple tracking on the last pushed type doesn't work is that Segments can be filled in asynchronously later and so you cannot know in a single pass whether the preceding content was a text node or not. This commit adds a concept of TextEmbedding which provides a best effort signal to Segments on whether they are embedded within text. This allows the later resolution of that Segment to add text separators when possibly necessary but avoid them when they are surely not.
The current implementation can only "peek" head if the segment is a the Root Segment or a Suspense Boundary Segment. In these cases we know there is no trailing text embedding and we can eliminate the separator at the end of the segment if the last emitted element was Text. In normal Segments we cannot peek and thus have to assume there might be a trailing text embedding and we issue a separator defensively. This should be rare in practice as it is assumed most components that will cause segment creation will also emit some markup at the edges.
* [Fizz] Improve separator efficiency when flushing delayed segments
The method by which we get segment markup into the DOM differs depending on when the Segment resolves.
If a Segment resolves before flushing begins for it's parent it will be emitted inline with the parent markup. In these cases separators may be necessary because they are how we clue the browser into breakup up text into distinct nodes that will later match up with what will be hydrated on the client.
If a Segment resolves after flushing has happened a script will be used to patch up the DOM in the client. when this happens if there are any text nodes on the boundary of the patch they won't be "merged" and thus will continue to have distinct representation as Nodes in the DOM. Thus we can avoid doing any separators at the boundaries in these cases.
After applying these changes the only time you will get text separators as follows
* in between serial text nodes that emit at the same time - these are necessary and cannot be eliminated unless we stop relying on the browser to automatically parse the correct text nodes when processing this HTML
* after a final text node in a non-boundary segment that resolves before it's parent has flushed - these are sometimes extraneous, like when the next emitted thing is a non-Text node.
In all other cases text separators should be omitted which means the general byte efficiency of this approach should be pretty good
* Support Document as a container for hydration and rendering
Previously Document was not handled effectively as a container. in particual when hydrating if there was a fallback to client rendering React would attempt to append a new <html> element into the document before clearing out the existing one which errored leaving the application in brokent state.
The initial approach I took was to recycle the documentElement and never remove or append it, always just moving it to the right fiber and appending the right children (heady/body) as needed. However in testing a simple approach in modern browsers it seems like treating the documentElement like any other element works fine. This change modifies the clearContainer method to remove the documentElement if the container is a DOCUMENT_NODE. Once the container is cleared React can append a new documentElement via normal means.
* Allow Document as container for createRoot
previously rendering into Document was broken and only hydration worked because React did not properly deal with the documentElement and would error in a broken state if used that way. With the previous commit addressing this limitation this change re-adds Document as a valid container for createRoot.
It should be noted that if you use document with createRoot it will drop anything a 3rd party scripts adds the page before rendering for the first time.
When hydrating a suspense boundary an error or a suspending fiber can often lead to a cascade of hydration errors. While in many cases these errors are simply discarded (e.g. when teh root does not commit and we fall back to client rendering) the use of invokeGuardedCallback can lead to many of these errors appearing as uncaught in the browser console. This change avoids error replaying using invokeGuardedCallback when we are hydrating a suspense boundary and have either already suspended or we have one previous error which was replayed.
* Add failing test case for #24384
If a components suspends during hydration we expect there to be mismatches with server rendered HTML but we were not always supressing warning messages related to these expected mismatches
* Mark hydration as suspending on every thrownException
previously hydration would only be marked as supsending when a genuine error was thrown. This created an opportunity for a hydration mismatch that would warn after which later hydration mismatches would not lead to warnings. By moving the marker check earlier in the thrownException function we get the hydration context to enter the didSuspend state on both error and thrown promise cases which eliminates this gap.
* Fix failing test related to client render fallbacks
This test was actually subject to the project identified in the issue fixed in this branch. After fixing the underlying issue the assertion logic needed to change to pick the right warning which now emits after hydration successfully completes on promise resolution. I changed the container type to 'section' to make the error message slightly easier to read/understand (for me)
* Only mark didSuspend on suspense path
For unknown reasons the didSuspend was being set only on the error path and nto the suspense path. The original change hoisted this to happen on both paths. This change moves the didSuspend call to the suspense path only. This appears to be a noop because if the error path marked didSuspend it would suppress later warnings but if it does not the warning functions themsevles do that suppression (after the first one which necessarily already happened)
* gate test on hydration fallback flags
* refactor didSuspend to didSuspendOrError
the orignial behavior applied the hydration warning bailout to error paths only. originally I moved it to Suspense paths only but this commit restores it to both paths and renames the marker function as didThrow rather than didSuspend
The logic here is that for either case if we get a mismatch in hydration we want to warm up components but effectively consider the hydration for this boundary halted
* factor tests to assert different behavior between prod and dev
* add DEV suffix to didSuspendOrError to better indicate this feature should only affect dev behavior
* move tests back to ReactDOMFizzServer-test
* fix comment casing
* drop extra flag gates in tests
* add test for user error case
* remove unnecessary gate
* Make test better
it now has an intentional client mismatch that would error if there wasn't suppression brought about by the earlier error. when it client renders it has the updated value not found in the server response but we do not see a hydration warning because it was superseded by the thrown error in that render
The previous escape was for Text into HTML and breaks script contents. The new escaping ensures that the script contents cannot prematurely close the host script tag by escaping script open and close string sequences using a unicode escape substitution.
I'm about to refactor part of the commit phase to use recursion instead
of iteration. As part of that change, we will no longer assign the
`return` pointer when traversing into a subtree. So I'm disabling
the internal warning that fires if the return pointer is not consistent
with the parent during the commit phase.
I had originally added this warning to help prevent mistakes when
traversing the tree iteratively, but since we're intentionally switching
to recursion instead, we don't need it.
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.
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.
* 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
The internal Container type represents the types of containers that React
can support in its internals that deal with containers.
This didn't include DocumentFragment which we support specifically for
rendering into shadow roots.
However, not all types makes sense to pass into the createRoot API.
One of those is comment nodes that is deprecated and we don't really fully
support. It really only exists for FB legacy.
For createRoot it doesn't make sense to pass a Document since that will try
to empty the document which removes the HTML tag which doesn't work.
Documents can only be passed to hydrateRoot.
Conversely I'm not sure we actually support hydrating a shadow root properly
so I excluded DocumentFragment from hydrateRoot.
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.
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.
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.
Before this change, we would sometimes write segments without any content
in them. For example for a Suspense boundary that immediately suspends
we might emit something like:
<div hidden id="123">
<template id="456"></template>
</div>
Where the outer div is just a temporary wrapper and the inner one is a
placeholder for something to be added later.
This serves no purpose.
We should ideally have a heuristic that holds back segments based on byte
size and time. However, this is a straight forward clear win for now.
* Flight side of server context
* 1 more test
* rm unused function
* flow+prettier
* flow again =)
* duplicate ReactServerContext across packages
* store default value when lazily initializing server context
* .
* better comment
* derp... missing import
* rm optional chaining
* missed feature flag
* React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED ??
* add warning if non ServerContext passed into useServerContext
* pass context in as array of arrays
* make importServerContext nott pollute the global context state
* merge main
* remove useServerContext
* dont rely on object getters in ReactServerContext and disallow JSX
* add symbols to devtools + rename globalServerContextRegistry to just ContextRegistry
* gate test case as experimental
* feedback
* remove unions
* Lint
* fix oopsies (tests/lint/mismatching arguments/signatures
* lint again
* replace-fork
* remove extraneous change
* rebase
* 1 more test
* rm unused function
* flow+prettier
* flow again =)
* duplicate ReactServerContext across packages
* store default value when lazily initializing server context
* .
* better comment
* derp... missing import
* rm optional chaining
* missed feature flag
* React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED ??
* add warning if non ServerContext passed into useServerContext
* pass context in as array of arrays
* make importServerContext nott pollute the global context state
* merge main
* remove useServerContext
* dont rely on object getters in ReactServerContext and disallow JSX
* add symbols to devtools + rename globalServerContextRegistry to just ContextRegistry
* gate test case as experimental
* feedback
* remove unions
* Lint
* fix oopsies (tests/lint/mismatching arguments/signatures
* lint again
* replace-fork
* remove extraneous change
* rebase
* reinline
* rebase
* add back changes lost due to rebase being hard
* emit chunk for provider
* remove case for React provider type
* update type for SomeChunk
* enable flag with experimental
* add missing types
* fix flow type
* missing type
* t: any
* revert extraneous type change
* better type
* better type
* feedback
* change import to type import
* test?
* test?
* remove react-dom
* remove react-native-renderer from react-server-native-relay/package.json
* gate change in FiberNewContext, getComponentNameFromType, use switch statement in FlightServer
* getComponentNameFromTpe: server context type gated and use displayName if available
* fallthrough
* lint....
* POP
* lint
* write chunks to a buffer with no re-use
chunks were previously enqueued to a ReadableStream as they were written. We now write them to a view over an ArrayBuffer
and enqueue them only when writing has completed or the buffer's size is exceeded. In addition this copy now ensures
we don't attempt to re-send buffers that have already been transferred.
* refactor writeChunk to be more defensive and efficient
We now defend against overflows using the next views length instead of the current one. this protects us against a future where we use byobRequest and we get longer initial views than we might create after overflowing the first time. Additionally we add in an optimization when we have completely filled up the currentView where we avoid creating subarrays of the chunk to write since it lands exactly on a view boundary. Finally we move the view creation to beginWriting to avoid a runtime check on each write and because we want to reset the view on each beginWriting call in case a throw elsewhere in the program leaves the currentView in an unfinished state
* add tests to exercise codepaths dealing with buffer overlows
* I forgot to call onFatalError
I can't figure out how to write a test for this because it only happens
when there is a bug in React itself which would then be fixed if we found
it.
We're also covered by the protection of ReadableStream which doesn't leak
other errors to us.
* Abort requests if the reader cancels
No need to continue computing at this point.
* Abort requests if node streams get destroyed
This is if the downstream cancels is for example.
* Rename Node APIs for Parity with allReady
The "Complete" terminology is a little misleading because not everything
has been written yet. It's just "Ready" to be written now.
onShellReady
onShellError
onAllReady
* 'close' should be enough
* Move onCompleteAll to .allReady Promise
The onCompleteAll callback can sometimes resolve before the promise that
returns the stream which is tough to coordinate. A more idiomatic API
for a one shot event is a Promise.
That way the way you render for SEO or SSG is:
const stream = await renderToReadableStream(...);
await stream.readyAll;
respondWith(stream);
Ideally this should be a sub-class of ReadableStream but we don't yet
compile these to ES6 and they'd had to be to native class to subclass
a native stream.
I have other ideas for overriding the .tee() method in a subclass anyway.
So this is inline with that strategy.
* Reject the Promise on fatal errors
The src property on the dom element will return a fully qualified name and this does not match the dom
src attribute or the props provided to react. instead of reading from the element and re-assigning the property we
assign the property from props which is how it was initially assigned during the render
Co-authored-by: Josh Story <story@hey.com>
Josh Larson
Josh StoryandMarco Salazar
Sebastian Silbermann
dan
Sebastian Markbåge
Andrew Clark
Ricky
alireza molaee
Yash Srivastav
salazarm
Josh StoryandJosh Story