* Replace Babel plugin with an ESLint plugin
* Fix ESLint rule violations
* Move shared conditions higher
* Test formatting nits
* Tweak ESLint rule
* Bugfix: inside else branch, 'if' tests are not satisfactory
* Use a stricter check for exactly if (__DEV__)
This makes it easier to see what's going on and matches dominant style in the codebase.
* Fix remaining files after stricter check
* Move Flight DOM to Webpack Specific Packagee
We'll have Webpack specific coupling so we need to ensure that it can be
versioned separately from various Webpack versions. We'll also have builds
for other bundlers in the future.
* Move to peerDep
* Move DOM Flight Tests
* Merge ReactFlightIntegration into ReactFlightDOM
This was an integration test. We can add to it.
* Fix fixture paths
* Rename ReactFlightStreamer -> ReactFlightServer
* Unify Browser/Node stream tests into one file and use the client reader
* Defer to the actual ReactDOM for HTML rendering for now
This will need to use a variant of Fizz to do inline SSR in Flight.
However, I don't want to build the whole impl right now but also don't
want to exclude the use case yet. So I outsource it to the existing
renderer. Ofc, this doesn't work with Suspense atm.
* Change demo to server
* Expose client in package.json
* Reorganize tests
We don't want unit tests but instead test how both server and clients work
together. So this merges server/client test files.
* Fill in the client implementation a bit
* Use new client in fixture
* Add Promise/Uint8Array to lint rule
I'll probably end up deleting these deps later but they're here for now.
* Add Flight Build and Unify HostFormat Config between Flight and Fizz
* Add basic resolution of models
* Add basic Flight fixture
Demonstrates the streaming protocol.
* Rename to flight-server to distinguish from the client parts
* Add Flight Client package and entry point
* Fix fixture
Special version of Jest's `it` for experimental tests. Tests marked as
experimental will run **both** stable and experimental modes. In
experimental mode, they work the same as the normal Jest methods. In
stable mode, they are **expected to fail**. This means we can detect
when a test previously marked as experimental can be un-marked when the
feature becomes stable. It also reduces the chances that we accidentally
add experimental APIs to the stable builds before we intend.
I added corresponding methods for the focus and skip APIs:
- `fit` -> `fit.experimental`
- `it.only` -> `it.only.experimental` or `it.experimental.only`
- `xit` -> `xit.experimental`
- `it.skip` -> `it.skip.experimental` or `it.experimental.skip`
Since `it` is an alias of `test`, `test.experimental` works, too.
`yarn build` defaults to building in experimental mode. To opt-out, set
the `RELEASE_CHANNEL` environment variable to `stable`. This is the same
as what we do when running tests via `yarn test`, to make local
development easier.
* Tests run in experimental mode by default
For local development, you usually want experiments enabled. Unless
the release channel is set with an environment variable, tests will
run with __EXPERIMENTAL__ set to `true`.
* Remove concurrent APIs from stable builds
Those who want to try concurrent mode should use the experimental
builds instead.
I've left the `unstable_` prefixed APIs in the Facebook build so we
can continue experimenting with them internally without blessing them
for widespread use.
* Turn on SSR flags in experimental build
* Remove prefixed concurrent APIs from www build
Instead we'll use the experimental builds when syncing to www.
* Remove "canary" from internal React version string
* Download correct artifacts for release channel
Experimental builds should pull artifacts from the
`process_artifacts_experimental` job.
I think instead of two separate CI workflows, a better approach might
be to build stable artifacts to the `build` directory and the
experimental artifacts to a `build_experimental` directory, and
generate both within the same workflow. This would take some work since
lots of things assume the output directory is `build`, but something
to consider in the future.
* Prevent experimental promotion to stable
Adds a check to the `prepare-stable` script to prevent experimental
builds from being published using stable semver versions.
* Don't bother including `unstable_` in error
The method names don't get stripped out of the production bundles
because they are passed as arguments to the error decoder.
Let's just always use the unprefixed APIs in the messages.
* Set up experimental builds
The experimental builds are packaged exactly like builds in the stable
release channel: same file structure, entry points, and npm package
names. The goal is to match what will eventually be released in stable
as closely as possible, but with additional features turned on.
Versioning and Releasing
------------------------
The experimental builds will be published to the same registry and
package names as the stable ones. However, they will be versioned using
a separate scheme. Instead of semver versions, experimental releases
will receive arbitrary version strings based on their content hashes.
The motivation is to thwart attempts to use a version range to match
against future experimental releases. The only way to install or depend
on an experimental release is to refer to the specific version number.
Building
--------
I did not use the existing feature flag infra to configure the
experimental builds. The reason is because feature flags are designed
to configure a single package. They're not designed to generate multiple
forks of the same package; for each set of feature flags, you must
create a separate package configuration.
Instead, I've added a new build dimension called the **release
channel**. By default, builds use the **stable** channel. There's
also an **experimental** release channel. We have the option to add more
in the future.
There are now two dimensions per artifact: build type (production,
development, or profiling), and release channel (stable or
experimental). These are separate dimensions because they are
combinatorial: there are stable and experimental production builds,
stable and experimental developmenet builds, and so on.
You can add something to an experimental build by gating on
`__EXPERIMENTAL__`, similar to how we use `__DEV__`. Anything inside
these branches will be excluded from the stable builds.
This gives us a low effort way to add experimental behavior in any
package without setting up feature flags or configuring a new package.
* Remove "Invariant Violation" from dev errors
When I made the change to compile `invariant` to throw expressions, I
left a small runtime to set the error's `name` property to "Invariant
Violation" to maintain the existing behavior.
I think we can remove it. The argument for keeping it is to preserve
continuity in error logs, but this only affects development errors,
anyway: production error messages are replaced with error codes.
* Pass prod error messages directly to constructor
Updates the `invariant` transform to pass an error message string
directly to the Error constructor, instead of mutating the
message property.
Turns this code:
```js
invariant(condition, 'A %s message that contains %s', adj, noun);
```
into this:
```js
if (!condition) {
throw Error(
__DEV__
? `A ${adj} message that contains ${noun}`
: formatProdErrorMessage(ERR_CODE, adj, noun)
);
}
```
The error transform works by replacing calls to `invariant` with
an `if` statement.
Since we're replacing a call expression with a statement, Babel wraps
the new statement in an immediately-invoked function expression (IIFE).
This wrapper is unnecessary in practice because our `invariant` calls
are always part of their own expression statement.
In the production bundle, the function wrappers are removed by Closure.
But they remain in the development bundles.
This commit updates the transform to confirm that an `invariant` call
expression's parent node is an expression statement. (If not, it throws
a transform error.)
Then, it replaces the expression statement instead of the expression
itself, effectively removing the extraneous IIFE wrapper.
* Rename lowPriorityWarning to lowPriorityWarningWithoutStack
This maintains parity with the other warning-like functions.
* Duplicate the toWarnDev tests to test toLowPriorityWarnDev
* Make a lowPriorityWarning version of warning.js
* Extract both variants in print-warning
Avoids parsing lowPriorityWarning.js itself as the way it forwards the
call to lowPriorityWarningWithoutStack is not analyzable.
* Idle updates should not be blocked by hidden work
Use the special `Idle` expiration time for updates that are triggered at
Scheduler's `IdlePriority`, instead of `Never`.
The key difference between Idle and Never¹ is that Never work can be
committed in an inconsistent state without tearing the UI. The main
example is offscreen content, like a hidden subtree.
¹ "Never" isn't the best name. I originally called it that because it
"never" expires, but neither does Idle. Since it's mostly used for
offscreen subtrees, we could call it "Offscreen." However, it's also
used for dehydrated Suspense boundaries, which are inconsistent in the
sense that they haven't finished yet, but aren't visibly inconsistent
because the server rendered HTML matches what the hydrated tree would
look like.
* Reset as early as possible using local variable
* Updates in a hidden effect should be Idle
I had made them Never to avoid an extra render when a hidden effect
updates the hidden component -- if they are Idle, we have to render once
at Idle, which bails out on the hidden subtree, then again at Never to
actually process the update -- but the problem of needing an extra
render pass to bail out hidden updates already exists and we should fix
that properly instead of adding yet another special case.
* Outline push/pop logic in `renderRoot`
I want to get rid of the the `isSync` argument to `renderRoot`, and
instead use separate functions for concurrent and synchronous render.
As a first step, this extracts the push/pop logic that happens before
and after the render phase into helper functions.
* Extract `catch` block into helper function
Similar to previous commit. Extract error handling logic into
a separate function so it can be reused.
* Fork `renderRoot` for sync and concurrent
Removes `isSync` argument in favor of separate functions.
* Extra "root completion" logic to separate function
Moving this out to avoid an accidental early return, which would
bypass the call to `ensureRootIsScheduled` and freeze the UI.
* Inline `renderRoot`
Inlines `renderRoot` into `performConcurrentWorkOnRoot` and
`performSyncWorkOnRoot`. This lets me remove the `isSync` argument
and also get rid of a redundant try-catch wrapper.
* [suspense][error handling] Add failing unit test
Covers an edge case where an error is thrown inside the complete phase
of a component that is in the return path of a component that suspends.
The second error should also be handled (i.e. able to be captured by
an error boundary.
The test is currently failing because there's a call to
`completeUnitOfWork` inside the main render phase `catch` block. That
call is not itself wrapped in try-catch, so anything that throws is
treated as a fatal/unhandled error.
I believe this bug is only observable if something in the host config
throws; and, only in legacy mode, because in concurrent/batched mode,
`completeUnitOfWork` on fiber that throws follows the "unwind" path
only, not the "complete" path, and the "unwind" path does not call
any host config methods.
* [scheduler][profiler] Start time of delayed tasks
Fixes a bug in the Scheduler profiler where the start time of a delayed
tasks is always 0.
* Remove ad hoc `throw`
Fatal errors (errors that are not captured by an error boundary) are
currently rethrown from directly inside the render phase's `catch`
block. This is a refactor hazard because the code in this branch has
to mirror the code that happens at the end of the function, when exiting
the render phase in the normal case.
This commit moves the throw to the end, using a new root exit status.
* Handle errors that occur on unwind
This is because the HostConfig can't be guaranteed to be consistent with
other code such as code that touches the DOM directly.
Ideally we'd have a more systemic solution to this since it will pop
up for other packages later too.
This implements 'usePress' in user-space as a combination of 'useKeyboard' and 'useTap'. The existing 'usePress' API is preserved for now. The previous 'usePress' implementation is moved to 'PressLegacy'.
* Add trusted types to react on client side
* Implement changes according to review
* Remove support for trusted URLs, change TrustedTypes to trustedTypes
* Add support for deprecated trusted URLs
* Apply PR suggesstions
* Warn only once, remove forgotten check, put it behind a flag
* Move comment
* Fix PR comments
* Fix html toString concatenation
* Fix forgotten else branch
* Fix PR comments
If a Scheduler profile runs without stopping, the event log will grow
unbounded. Eventually it will run out of memory and the VM will throw
an error.
To prevent this from happening, let's automatically stop the profiler
once the log exceeds a certain limit. We'll also print a warning with
advice to call `stopLoggingProfilingEvents` explicitly.
* Don't invoke listeners on parent of dehydrated event target
* Move Suspense boundary check to getClosestInstanceFromNode
Now getClosestInstanceFromNode can return either a host component,
host text component or suspense component when the suspense
component is dehydrated.
We then use that to ignore events on a suspense component.
* Attach the HostRoot fiber to the DOM container
This lets us detect if an event happens on this root's subtree before it
has rendered something.
* Add todo
The approach of checking isFiberMounted answers if we might be in an
in-progress hydration but it doesn't answer which root or boundary
might be in-progress so we don't know what to wait for.
This needs some refactoring.
* Refactor isFiberMountedImpl to getNearestMountedFiber
We'll need the nearest boundary for event replaying so this prepares for
that.
This surfaced an issue that we attach Hydrating tag on the root but normally
this (and Placement) is attached on the child. This surfaced an issue
that this can lead to both Placement and Hydrating effects which is not
supported so we need to ensure that we only ever use one or the other.
* Add todo for bug I spotted
* Cache tags
* Check the ContainerInstanceKey before the InstanceKey
The container is inside the instance, so we must find it before the
instance, since otherwise we'll miss it.
This is a partial replacement for the 'Press' responder:
1. `useTap` is scoped to pointers (no keyboard support). Our current thinking is
that "responders" should be limited to working with pointers, and that they can
be combined with 'useKeyboard' in user-space. For example, we might create a
'usePress' hook in user-space that combines 'useTap' with 'useKeyboard' to react
to both pointers and keyboard interactions.
2. `useTap` cancels the gesture once the pointer moves over an element that is
not within the responder target's subtree. This differs from `usePress` (and
React Native), where the gesture remains active after the pointer exits the
target's subtree and is restarted once the pointer reenters. One of the
drawbacks with the `usePress` behavior is that it requires repeatedly measuring
DOM elements (which can cause jank) to perform hit region tests. `useTap` avoids
doing this and relies on `document.elementFromPoint` only to support the
TouchEvent fallbacks.
3. `useTap` calls `onTapUpdate` when the active gesture's state changes,
`onTapEnd` when the gesture successfully completes. and `onTapCancel` when it
fails. There is no `onTap` callback. `usePress` did not explicitly report back
when the gesture failed, and product developers were confused about the
difference between `onPress` and `onPressEnd`.
4. `useTap` explicitly separates the PointerEvent implementation from the
MouseEvent/TouchEvent fallback.
5. `useTap` has better unit test coverage . All pointer types and the fallback
environment are tested. The shape of the gesture state object is also defined
and tested.