Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Always warn if client component suspends with an uncached promise #28159

Merged
merged 2 commits into from
Jan 30, 2024
Merged

Always warn if client component suspends with an uncached promise #28159

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
fd66aa6
Always warn if client component is an async function
acdlite Jan 30, 2024
54b1617
Warn if uncached promise suspends during render
acdlite Jan 30, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
49 changes: 10 additions & 39 deletions packages/react-reconciler/src/ReactFiberHooks.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -388,10 +388,7 @@ function warnOnHookMismatchInDev(currentHookName: HookType): void {
}
}

function warnIfAsyncClientComponent(
Component: Function,
componentDoesIncludeHooks: boolean,
) {
function warnIfAsyncClientComponent(Component: Function) {
if (__DEV__) {
// This dev-only check only works for detecting native async functions,
// not transpiled ones. There's also a prod check that we use to prevent
Expand All @@ -402,40 +399,16 @@ function warnIfAsyncClientComponent(
// $FlowIgnore[method-unbinding]
Object.prototype.toString.call(Component) === '[object AsyncFunction]';
if (isAsyncFunction) {
// Encountered an async Client Component. This is not yet supported,
// except in certain constrained cases, like during a route navigation.
// Encountered an async Client Component. This is not yet supported.
const componentName = getComponentNameFromFiber(currentlyRenderingFiber);
if (!didWarnAboutAsyncClientComponent.has(componentName)) {
didWarnAboutAsyncClientComponent.add(componentName);

// Check if this is a sync update. We use the "root" render lanes here
// because the "subtree" render lanes may include additional entangled
// lanes related to revealing previously hidden content.
const root = getWorkInProgressRoot();
const rootRenderLanes = getWorkInProgressRootRenderLanes();
if (root !== null && includesBlockingLane(root, rootRenderLanes)) {
console.error(
'async/await is not yet supported in Client Components, only ' +
'Server Components. This error is often caused by accidentally ' +
"adding `'use client'` to a module that was originally written " +
'for the server.',
);
} else {
// This is a concurrent (Transition, Retry, etc) render. We don't
// warn in these cases.
//
// However, Async Components are forbidden to include hooks, even
// during a transition, so let's check for that here.
//
// TODO: Add a corresponding warning to Server Components runtime.
if (componentDoesIncludeHooks) {
console.error(
'Hooks are not supported inside an async component. This ' +
"error is often caused by accidentally adding `'use client'` " +
'to a module that was originally written for the server.',
);
}
}
console.error(
'async/await is not yet supported in Client Components, only ' +
'Server Components. This error is often caused by accidentally ' +
"adding `'use client'` to a module that was originally written " +
'for the server.',
);
}
}
}
Expand Down Expand Up @@ -521,6 +494,8 @@ export function renderWithHooks<Props, SecondArg>(
// Used for hot reloading:
ignorePreviousDependencies =
current !== null && current.type !== workInProgress.type;

warnIfAsyncClientComponent(Component);
}

workInProgress.memoizedState = null;
Expand Down Expand Up @@ -637,10 +612,6 @@ function finishRenderingHooks<Props, SecondArg>(
): void {
if (__DEV__) {
workInProgress._debugHookTypes = hookTypesDev;

const componentDoesIncludeHooks =
workInProgressHook !== null || thenableIndexCounter !== 0;
warnIfAsyncClientComponent(Component, componentDoesIncludeHooks);
}

// We can assume the previous dispatcher is always this one, since we set it
Expand Down
63 changes: 58 additions & 5 deletions packages/react-reconciler/src/ReactFiberThenable.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,24 @@ import {getWorkInProgressRoot} from './ReactFiberWorkLoop';
import ReactSharedInternals from 'shared/ReactSharedInternals';
const {ReactCurrentActQueue} = ReactSharedInternals;

export opaque type ThenableState = Array<Thenable<any>>;
opaque type ThenableStateDev = {
didWarnAboutUncachedPromise: boolean,
thenables: Array<Thenable<any>>,
};

opaque type ThenableStateProd = Array<Thenable<any>>;

export opaque type ThenableState = ThenableStateDev | ThenableStateProd;

function getThenablesFromState(state: ThenableState): Array<Thenable<any>> {
if (__DEV__) {
const devState: ThenableStateDev = (state: any);
return devState.thenables;
} else {
const prodState = (state: any);
return prodState;
}
}

// An error that is thrown (e.g. by `use`) to trigger Suspense. If we
// detect this is caught by userspace, we'll log a warning in development.
Expand Down Expand Up @@ -56,7 +73,14 @@ export const noopSuspenseyCommitThenable = {
export function createThenableState(): ThenableState {
// The ThenableState is created the first time a component suspends. If it
// suspends again, we'll reuse the same state.
return [];
if (__DEV__) {
return {
didWarnAboutUncachedPromise: false,
thenables: [],
};
} else {
return [];
}
}

export function isThenableResolved(thenable: Thenable<mixed>): boolean {
Expand All @@ -74,15 +98,44 @@ export function trackUsedThenable<T>(
if (__DEV__ && ReactCurrentActQueue.current !== null) {
ReactCurrentActQueue.didUsePromise = true;
}

const previous = thenableState[index];
const trackedThenables = getThenablesFromState(thenableState);
const previous = trackedThenables[index];
if (previous === undefined) {
thenableState.push(thenable);
trackedThenables.push(thenable);
} else {
if (previous !== thenable) {
// Reuse the previous thenable, and drop the new one. We can assume
// they represent the same value, because components are idempotent.

if (__DEV__) {
const thenableStateDev: ThenableStateDev = (thenableState: any);
if (!thenableStateDev.didWarnAboutUncachedPromise) {
// We should only warn the first time an uncached thenable is
// discovered per component, because if there are multiple, the
// subsequent ones are likely derived from the first.
//
// We track this on the thenableState instead of deduping using the
// component name like we usually do, because in the case of a
// promise-as-React-node, the owner component is likely different from
// the parent that's currently being reconciled. We'd have to track
// the owner using state, which we're trying to move away from. Though
// since this is dev-only, maybe that'd be OK.
//
// However, another benefit of doing it this way is we might
// eventually have a thenableState per memo/Forget boundary instead
// of per component, so this would allow us to have more
// granular warnings.
thenableStateDev.didWarnAboutUncachedPromise = true;

// TODO: This warning should link to a corresponding docs page.
console.error(
'A component was suspended by an uncached promise. Creating ' +
'promises inside a Client Component or hook is not yet ' +
'supported, except via a Suspense-compatible library or framework.',
);
}
}

// Avoid an unhandled rejection errors for the Promises that we'll
// intentionally ignore.
thenable.then(noop, noop);
Expand Down
96 changes: 68 additions & 28 deletions packages/react-reconciler/src/__tests__/ReactUse-test.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -230,11 +230,17 @@ describe('ReactUse', () => {
}

const root = ReactNoop.createRoot();
await act(() => {
startTransition(() => {
root.render(<App />);
await expect(async () => {
await act(() => {
startTransition(() => {
root.render(<App />);
});
});
});
}).toErrorDev([
'A component was suspended by an uncached promise. Creating ' +
'promises inside a Client Component or hook is not yet ' +
'supported, except via a Suspense-compatible library or framework.',
]);
assertLog(['ABC']);
expect(root).toMatchRenderedOutput('ABC');
});
Expand Down Expand Up @@ -394,11 +400,20 @@ describe('ReactUse', () => {
}

const root = ReactNoop.createRoot();
await act(() => {
startTransition(() => {
root.render(<App />);
await expect(async () => {
await act(() => {
startTransition(() => {
root.render(<App />);
});
});
});
}).toErrorDev([
'A component was suspended by an uncached promise. Creating ' +
'promises inside a Client Component or hook is not yet ' +
'supported, except via a Suspense-compatible library or framework.',
'A component was suspended by an uncached promise. Creating ' +
'promises inside a Client Component or hook is not yet ' +
'supported, except via a Suspense-compatible library or framework.',
]);
assertLog([
// First attempt. The uncached promise suspends.
'Suspend! [Async]',
Expand Down Expand Up @@ -1733,25 +1748,38 @@ describe('ReactUse', () => {
);
});

test('warn if async client component calls a hook (e.g. useState)', async () => {
async function AsyncClientComponent() {
useState();
return <Text text="Hi" />;
}
test(
'warn if async client component calls a hook (e.g. useState) ' +
'during a non-sync update',
async () => {
async function AsyncClientComponent() {
useState();
return <Text text="Hi" />;
}

const root = ReactNoop.createRoot();
await expect(async () => {
await act(() => {
startTransition(() => {
root.render(<AsyncClientComponent />);
const root = ReactNoop.createRoot();
await expect(async () => {
await act(() => {
startTransition(() => {
root.render(<AsyncClientComponent />);
});
});
});
}).toErrorDev([
'Hooks are not supported inside an async component. This ' +
"error is often caused by accidentally adding `'use client'` " +
'to a module that was originally written for the server.',
]);
});
}).toErrorDev([
// Note: This used to log a different warning about not using hooks
// inside async components, like we do on the server. Since then, we
// decided to warn for _any_ async client component regardless of
// whether the update is sync. But if we ever add back support for async
// client components, we should add back the hook warning.
'async/await is not yet supported in Client Components, only Server ' +
'Components. This error is often caused by accidentally adding ' +
"`'use client'` to a module that was originally written for " +
'the server.',
'A component was suspended by an uncached promise. Creating ' +
'promises inside a Client Component or hook is not yet ' +
'supported, except via a Suspense-compatible library or framework.',
]);
},
);

test('warn if async client component calls a hook (e.g. use)', async () => {
const promise = Promise.resolve();
Expand All @@ -1769,9 +1797,21 @@ describe('ReactUse', () => {
});
});
}).toErrorDev([
'Hooks are not supported inside an async component. This ' +
"error is often caused by accidentally adding `'use client'` " +
'to a module that was originally written for the server.',
// Note: This used to log a different warning about not using hooks
// inside async components, like we do on the server. Since then, we
// decided to warn for _any_ async client component regardless of
// whether the update is sync. But if we ever add back support for async
// client components, we should add back the hook warning.
'async/await is not yet supported in Client Components, only Server ' +
'Components. This error is often caused by accidentally adding ' +
"`'use client'` to a module that was originally written for " +
'the server.',
'A component was suspended by an uncached promise. Creating ' +
'promises inside a Client Component or hook is not yet ' +
'supported, except via a Suspense-compatible library or framework.',
'A component was suspended by an uncached promise. Creating ' +
'promises inside a Client Component or hook is not yet ' +
'supported, except via a Suspense-compatible library or framework.',
]);
});
});