In legacy mode, a test can get into a situation where passive effects are
"dangling" — an update finished, and scheduled some passive effects,
but the effects don't flush.
This is why React warns if you don't wrap updates in act. The act API is
responsible for flushing passive effects. But there are some cases where
the act API (in legacy roots) intentionally doesn't warn, like updates
that originate from roots and classes. It's possible those updates will
render children that contain useEffect. Because of this, dangling
effects are still possible, and React doesn't warn about it.
So we implemented a second act warning for dangling effects.
However, in concurrent roots, we now enforce that all APIs that schedule
React work must be wrapped in act. There's no scenario where dangling
passive effects can happen that doesn't already trigger the warning for
updates. So the dangling effects warning is redundant.
The warning was never part of a public release. It was only enabled
in concurrent roots.
So we can delete it.
* Move isActEnvironment check to function that warns
I'm about to fork the behavior in legacy roots versus concurrent roots
even further, so I'm lifting this up so I only have to fork once.
* Lift `mode` check, too
Similar to previous commit. I only want to check this once. Not for
performance reasons, but so the logic is easier to follow.
* Expand act warning to include non-hook APIs
In a test environment, React warns if an update isn't wrapped with act
— but only if the update originates from a hook API, like useState.
We did it this way for backwards compatibility with tests that were
written before the act API was introduced. Those tests didn't require
act, anyway, because in a legacy root, all tasks are synchronous except
for `useEffect`.
However, in a concurrent root, nearly every task is asynchronous. Even
tasks that are synchronous may spawn additional asynchronous work. So
all updates need to be wrapped with act, regardless of whether they
originate from a hook, a class, a root, or any other type of component.
This commit expands the act warning to include any API that triggers
an update.
It does not currently account for renders that are caused by a Suspense
promise resolving; those are modelled slightly differently from updates.
I'll fix that in the next step.
I also removed the check for whether an update is batched. It shouldn't
matter, because even a batched update can spawn asynchronous work, which
needs to be flushed by act.
This change only affects concurrent roots. The behavior in legacy roots
is the same.
* Expand act warning to include Suspense resolutions
For the same reason we warn when an update is not wrapped with act,
we should warn if a Suspense promise resolution is not wrapped with act.
Both "pings" and "retries".
Legacy root behavior is unchanged.
This is an initial, partial implementation of a cleanup mechanism for the experimental Cache API. The idea is that consumers of the Cache API can register to be informed when a given Cache instance is no longer needed so that they can perform associated cleanup tasks to free resources stored in the cache. A canonical example would be cancelling pending network requests.
An overview of the high-level changes:
* Changes the `Cache` type from a Map of cache instances to be an object with the original Map of instances, a reference count (to count roughly "active references" to the cache instances - more below), and an AbortController.
* Adds a new public API, `unstable_getCacheSignal(): AbortSignal`, which is callable during render. It returns an AbortSignal tied to the lifetime of the cache - developers can listen for the 'abort' event on the signal, which React now triggers when a given cache instance is no longer referenced.
* Note that `AbortSignal` is a web standard that is supported by other platform APIs; for example a signal can be passed to `fetch()` to trigger cancellation of an HTTP request.
* Implements the above - triggering the 'abort' event - by handling passive mount/unmount for HostRoot and CacheComponent fiber nodes.
Cases handled:
* Aborted transitions: we clean up a new cache created for an aborted transition
* Suspense: we retain a fresh cache instance until a suspended tree resolves
For follow-ups:
* When a subsequent cache refresh is issued before a previous refresh completes, the refreshes are queued. Fresh cache instances for previous refreshes in the queue should be cleared, retaining only the most recent cache. I plan to address this in a follow-up PR.
* If a refresh is cancelled, the fresh cache should be cleaned up.
DevTools (and its profilers) should not require users to be familiar with React internals. Although the scheduling profiler includes a CPU sample flame graph, it's there for advanced use cases and shouldn't be required to identify common performance issues.
This PR proposes adding new marks around component effects. This will enable users to identify components with slow effect create/destroy functions without requiring them to dig through the call stack. (Once #22529 lands, these new marks will also include component stacks, making them more useful still.)
For example, here's a profile with a long-running effect. Without this change, it's not clear why the effects phase takes so long. After this change, it's more clear why that the phase is longer because of a specific component.
We may consider adding similar marks around render phase hooks like useState, useReducer, useMemo. I avoided doing that in this PR because it would be a pretty pervasive change to the ReactFiberHooks file.
Note that this change should have no effect on production bundles since everything is guarded behind a profiling feature flag.
Going to tag more people than I normally would for this pR, since it touches both reconciler and DevTools packages. Feel free to ignore though if you don't have strong feelings.
Note that although this PR adds new marks to the scheduling profiler, it's done in a way that's backwards compatible for older profiles.
This commit adds code to all React bundles to explicitly register the beginning and ending of the module. This is done by creating Error objects (which capture the file name, line number, and column number) and passing them explicitly to a DevTools hook (when present).
Next, as the Scheduling Profiler logs metadata to the User Timing API, it prints these module ranges along with other metadata (like Lane values and profiler version number).
Lastly, the Scheduling Profiler UI compares stack frames to these ranges when drawing the flame graph and dims or de-emphasizes frames that fall within an internal module.
The net effect of this is that user code (and 3rd party code) stands out clearly in the flame graph while React internal modules are dimmed.
Internal module ranges are completely optional. Older profiling samples, or ones recorded without the React DevTools extension installed, will simply not dim the internal frames.
* Add option to inject bootstrap scripts
These are emitted right after the shell as flushed.
* Update ssr fixtures to use bootstrapScripts instead of manual script tag
* Add option to FB renderer too
* Clear extra nodes if there's a mismatch within a suspense boundary
This usually happens when we exit out a DOM node but a suspense boundary
is a virtual DOM node and we didn't do it in that case because we took a
short cut by calling resetHydrationState directly since we know we won't
need to pop.
* Tighten up the types of getFirstHydratableChild
We currently call getFirstHydratableChild to step into the children of
a suspense boundary. This can be a text node or a suspense boundary
which isn't compatible with getFirstHydratableChild, and we cheat the type.
This accidentally works because .firstChild always returns null on those
nodes in the DOM.
This just makes that explicit.
@huozhi tried this out and says it's working as expected. I think we
can go ahead and move this into the stable channel, so that it is
available in the React 18 alpha releases.
* Add a failing test for Suspense hydration
* Include salazarm's changes to the test
* The hydration parent of a suspense boundary should be the boundary itself
This eventually got set when we popped back out of its children but it
doesn't start out that way.
This fixes it so that the boundary parent is always the suspense boundary.
* We now need to log errors with a suspense boundary as a parent
For now, we just log this with commentNode.parentNode as the parent for
purposes of the error message.
* Make a special getFirstHydratableChildWithinSuspenseInstance
We currently call getNextHydratableSibling but conceptually it's the child
of the boundary. It just happens to be that when we use comment nodes, we
need to call nextSibling in the DOM.
This makes this separation a bit clearer.
* Sync old fork
Co-authored-by: Dan Abramov <dan.abramov@me.com>
* Remove `jest` global check in concurrent roots
In concurrent mode, instead of checking `jest`, we check the new
`IS_REACT_ACT_ENVIRONMENT` global. The default behavior is `false`.
Legacy mode behavior is unchanged.
React's own internal test suite use a custom version of `act` that works
by mocking the Scheduler — rather than the "real" act used publicly. So
we don't enable the flag in our repo.
* Warn if `act` is called in wrong environment
Adds a warning if `act` is called but `IS_REACT_ACT_ENVIRONMENT` is not
enabled. The goal is to prompt users to correctly configure their
testing environment, so that if they forget to use `act` in a different
test, we can detect and warn about.
It's expected that the environment flag will be configured by the
testing framework. For example, a Jest plugin. We will link to the
relevant documentation page, once it exists.
The warning only fires in concurrent mode. Legacy roots will keep the
existing behavior.
* Extract `act` environment check into function
`act` checks the environment to determine whether to fire a warning.
We're changing how this check works in React 18. As a first step, this
refactors the logic into a single function. No behavior changes yet.
* Use IS_REACT_ACT_ENVIRONMENT to disable warnings
If `IS_REACT_ACT_ENVIRONMENT` is set to `false`, we will suppress
any `act` warnings. Otherwise, the behavior of `act` is the same as in
React 17: if `jest` is defined, it warns.
In concurrent mode, the plan is to remove the `jest` check and only warn
if `IS_REACT_ACT_ENVIRONMENT` is true. I have not implemented that
part yet.
## Summary
This commit is a proposal for handling duplicate installation of DevTools, in particular scoped to duplicates such as a dev build or the internal versions of DevTools installed alongside the Chrome Web Store extension.
Specifically, this commit makes it so when another instance of the DevTools extension is installed alongside the extension installed from the Chrome Web Store, we don't produce a stream of errors or crash Chrome, which is what would usually happen in this case.
### Detecting Duplicate Installations
- First, we check what type of installation the extension is: from the Chrome Web Store, the internal build of the extension, or a local development build.
- If the extension is from the **Chrome Web Store**:
- During initialization, we first check if the internal or local builds of the extension have already been installed and are enabled. To do this, we send a [cross-extension message](https://developer.chrome.com/docs/extensions/mv3/messaging/#external) to the internal and local builds of the extension using their extension IDs.
- We can do this because the extension ID for the internal build (and for the Chrome Web Store) is a stable ID.
- For the local build, at build time we hardcode a [`key` in the `manifest.json`](https://developer.chrome.com/docs/extensions/mv2/manifest/key/) which allows us to have a stable ID even for local builds.
- If we detect that the internal or local extensions are already installed, then we skip initializing the current extension altogether so as to not conflict with the other versions. This means we don't initialize the frontend or the backend at all.
- If the extension is the **Internal Build**:
- During initialization, we first check if the local builds of the extension has already been installed and is enabled. To do this, we send a [cross-extension message](https://developer.chrome.com/docs/extensions/mv3/messaging/#external) to the local build of the extension using its extension ID.
- We can do this for the local build because at build time we hardcode a [`key` in the `manifest.json`](https://developer.chrome.com/docs/extensions/mv2/manifest/key/) which allows us to have a stable ID even for local builds.
- If we detect that the local extension is already installed, then we skip initializing the current extension altogether so as to not conflict with the that version. This means we don't initialize the frontend or the backend at all.
- If the extension is a **Local Dev Build**:
- Since other extensions check for the existence of this extension and disable themselves if they detect it, we don't need any special handling during initialization and assume that there are no duplicate extensions. This means that we will generally prefer keeping this extension enabled.
This behavior means that the order of priority for keeping an extension enabled is the following:
1. Local build
2. Internal build
3. Public build
### Preventing duplicate backend initialization
Note that the backend is injected and initialized by the content script listening to a message posted to the inspected window (via `postMessage`). Since the content script will be injected twice, once each by each instance of the extension, even if we initialize the extension once, both content scripts would still receive the single message posted from the single frontend, and it would then still inject and initialize the backend twice.
In order to prevent this, we also add the extension ID to the message for injecting the backend. That way each content script can check if the message comes from its own extension, and if not it can ignore the message and avoid double injecting the backend.
### Other approaches
- I considered using the [`chrome.management`](https://developer.chrome.com/docs/extensions/reference/management/) API generally to detect other installations, but that requires adding additional permissions to our production extension, which didn't seem ideal.
- I also considered a few options of writing a special flag to the inspected window and checking for it before initializing the extension. However, it's hard to avoid race conditions in that case, and it seemed more reliable to check specifically for the WebStore extension, which is realistically where we would encounter the overlap.
### Rollout
- This commit needs to be published and rolled out to the Chrome Web Store first.
- After this commit is published to the Chrome Web Store, any duplicate instances of the extension that are built and installed after this commit will no longer conflict with the Chrome Web Store version.
### Next Steps
- In a subsequent PR, I will extend this code to show a warning when duplicate extensions have been detected.
Part of #22486
## How did you test this change?
### Basic Testing
- yarn flow
- yarn test
- yarn test-build-devtools
### Double installation testing
Testing double-installed extensions for this commit is tricky because we are relying on the extension ID of the internal and Chrome Web Store extensions, but we obviously can't actually test the Web Store version (since we can't modify the already published version).
In order to simulate duplicate extensions installed, I did the following process:
- Built separate extensions where I hardcoded a constant for whether the extension is internal or public (e.g. `EXTENSION_INSTALLATION_TYPE = 'internal'`). Then I installed these built extensions corresponding to the "internal" and "Web Store" builds.
- Build and run the regular development extension (with `yarn build:chrome:dev && yarn test:chrome`), using the extension IDs of the previously built extensions as the "internal" and "public" extension IDs.
With this set up in place, I tested the following on pages both with and without React:
- When only the local extension enabled, DevTools works normally.
- When only the "internal" extension enabled, DevTools works normally.
- When only the "public" extension enabled, DevTools works normally.
- When "internal" and "public" extensions are installed, "public" extension is disabled and "internal" extension works normally.
- When the local extension runs alongside the other extensions, other extensions disable themselves and local build works normally.
- When we can't recognize what type of build the extension corresponds to, we show an error.
- When all 3 extensions are installed and enabled in all different combinations, DevTools no longer produces errors or crashes Chrome, and works normally.
* Handle render phase updates explicitly
We fire a warning in development if a component is updated during
the render phase (with the exception of local hook updates, which have
their own defined behavior).
Because it's not a supported React pattern, we don't have that many
tests that trigger this path. But it is meant to have reasonable
semantics when it does happen, so that if it accidentally ships to
production, the app doesn't crash unnecessarily. The behavior is not
super well-defined, though.
There are also some _internal_ React implementation details that
intentionally to rely on this behavior. Most prominently, selective
hydration and useOpaqueIdentifier.
I need to tweak the behavior of render phase updates slightly as part
of a fix for useOpaqueIdentifier. This shouldn't cause a user-facing
change in behavior outside of useOpaqueIdentifier, but it does require
that we explicitly model render phase updates.
* Bugfix: Nested useOpaqueIdentifier calls
Fixes an issue where multiple useOpaqueIdentifier hooks are upgraded
to client ids within the same render.
The way the upgrade works is that useOpaqueIdentifier schedules a
render phase update then throws an error to trigger React's error
recovery mechanism.
The normal error recovery mechanism is designed for errors that occur
as a result of interleaved mutations, so we usually only retry a single
time, synchronously, before giving up.
useOpaqueIdentifier is different because the error its throws when
upgrading is not caused by an interleaved mutation. Rather, it happens
when an ID is referenced for the first time inside a client-rendered
tree (i.e. sommething that wasn't part of the initial server render).
The fact that it relies on the error recovery mechanism is an
implementation detail. And a single recovery attempt may be
insufficient. For example, if a parent and a child component may
reference different ids, and both are mounted as a result of the same
client update, that will trigger two separate error recovery attempts.
Because render phase updates are not allowed when triggered from
userspace — we log a warning in developement to prevent them —
we can assume that if something does update during the render phase, it
is one of our "legit" implementation details like useOpaqueIdentifier.
So we can keep retrying until we succeed — up to a limit, to protect
against inifite loops. I chose 50 since that's the limit we use for
commit phase updates.
* Rename pipeToNodeWritable to renderToNodePipe
* Add startWriting API to Flight
We don't really need it in this case because there's way less reason to
delay the stream in Flight.
* Pass the destination to startWriting instead of renderToNode
* Rename startWriting to pipe
This mirrors the ReadableStream API in Node
* Error codes
* Rename to renderToPipeableStream
This mimics the renderToReadableStream API for the browser.
Erik Andersson
Shu Ding
btea
Andrew Clark
Joseph Savona
Brian Vaughn
Konstantin Popov
Juan
Sebastian Markbåge
Gabriel Trompiz
Abhay Gupta
BIKI DAS
salazarm
Daishi Kato
