@samitouri / QOS-React-2 / commits / 5c8dabf886

Detect and warn about native async function components in development (#27031)

Adds a development warning to complement the error introduced by https://github.com/facebook/react/pull/27019. We can detect and warn about async client components by checking the prototype of the function. This won't work for environments where async functions are transpiled, but for native async functions, it allows us to log an earlier warning during development, including in cases that don't trigger the infinite loop guard added in https://github.com/facebook/react/pull/27019. It does not supersede the infinite loop guard, though, because that mechanism also prevents the app from crashing. I also added a warning for calling a hook inside an async function. This one fires even during a transition. We could add a corresponding warning to Flight, since hooks are not allowed in async Server Components, either. (Though in both environments, this is better handled by a lint rule.)

Andrew Clark committed Jul 1, 2023 at 22:44 UTC 5c8dabf8864e1d826c831d6096b2dfa66309961a

5 files changed +188 -34

packages/react-reconciler/src/ReactFiberHooks.js

+77 -8

@@ -163,9 +163,11 @@ export type UpdateQueue<S, A> = {

163 let didWarnAboutMismatchedHooksForComponent;

164 let didWarnUncachedGetSnapshot: void | true;

165 let didWarnAboutUseWrappedInTryCatch;

166 +let didWarnAboutAsyncClientComponent;

167 if (__DEV__) {

168 didWarnAboutMismatchedHooksForComponent = new Set<string | null>();

169 didWarnAboutUseWrappedInTryCatch = new Set<string | null>();

170 + didWarnAboutAsyncClientComponent = new Set<string | null>();

171 }

172

173 export type Hook = {

@@ -370,6 +372,59 @@ function warnOnHookMismatchInDev(currentHookName: HookType): void {

372 }

373 }

374

375 +function warnIfAsyncClientComponent(

376 + Component: Function,

377 + componentDoesIncludeHooks: boolean,

378 +) {

379 + if (__DEV__) {

380 + // This dev-only check only works for detecting native async functions,

381 + // not transpiled ones. There's also a prod check that we use to prevent

382 + // async client components from crashing the app; the prod one works even

383 + // for transpiled async functions. Neither mechanism is completely

384 + // bulletproof but together they cover the most common cases.

385 + const isAsyncFunction =

386 + // $FlowIgnore[method-unbinding]

387 + Object.prototype.toString.call(Component) === '[object AsyncFunction]';

388 + if (isAsyncFunction) {

389 + // Encountered an async Client Component. This is not yet supported,

390 + // except in certain constrained cases, like during a route navigation.

391 + const componentName = getComponentNameFromFiber(currentlyRenderingFiber);

392 + if (!didWarnAboutAsyncClientComponent.has(componentName)) {

393 + didWarnAboutAsyncClientComponent.add(componentName);

394 +

395 + // Check if this is a sync update. We use the "root" render lanes here

396 + // because the "subtree" render lanes may include additional entangled

397 + // lanes related to revealing previously hidden content.

398 + const root = getWorkInProgressRoot();

399 + const rootRenderLanes = getWorkInProgressRootRenderLanes();

400 + if (root !== null && includesBlockingLane(root, rootRenderLanes)) {

401 + console.error(

402 + 'async/await is not yet supported in Client Components, only ' +

403 + 'Server Components. This error is often caused by accidentally ' +

404 + "adding `'use client'` to a module that was originally written " +

405 + 'for the server.',

406 + );

407 + } else {

408 + // This is a concurrent (Transition, Retry, etc) render. We don't

409 + // warn in these cases.

410 + //

411 + // However, Async Components are forbidden to include hooks, even

412 + // during a transition, so let's check for that here.

413 + //

414 + // TODO: Add a corresponding warning to Server Components runtime.

415 + if (componentDoesIncludeHooks) {

416 + console.error(

417 + 'Hooks are not supported inside an async component. This ' +

418 + "error is often caused by accidentally adding `'use client'` " +

419 + 'to a module that was originally written for the server.',

420 + );

421 + }

422 + }

423 + }

424 + }

425 + }

426 +}

427 +

428 function throwInvalidHookError() {

429 throw new Error(

430 'Invalid hook call. Hooks can only be called inside of the body of a function component. This could happen for' +

@@ -554,20 +609,28 @@ export function renderWithHooks<Props, SecondArg>(

609 }

610 }

611

557 - finishRenderingHooks(current, workInProgress);

612 + finishRenderingHooks(current, workInProgress, Component);

613

614 return children;

615 }

616

562 -function finishRenderingHooks(current: Fiber | null, workInProgress: Fiber) {

563 - // We can assume the previous dispatcher is always this one, since we set it

564 - // at the beginning of the render phase and there's no re-entrance.

565 - ReactCurrentDispatcher.current = ContextOnlyDispatcher;

566 -

617 +function finishRenderingHooks<Props, SecondArg>(

618 + current: Fiber | null,

619 + workInProgress: Fiber,

620 + Component: (p: Props, arg: SecondArg) => any,

621 +): void {

622 if (__DEV__) {

623 workInProgress._debugHookTypes = hookTypesDev;

624 +

625 + const componentDoesIncludeHooks =

626 + workInProgressHook !== null || thenableIndexCounter !== 0;

627 + warnIfAsyncClientComponent(Component, componentDoesIncludeHooks);

628 }

629

630 + // We can assume the previous dispatcher is always this one, since we set it

631 + // at the beginning of the render phase and there's no re-entrance.

632 + ReactCurrentDispatcher.current = ContextOnlyDispatcher;

633 +

634 // This check uses currentHook so that it works the same in DEV and prod bundles.

635 // hookTypesDev could catch more cases (e.g. context) but only in DEV bundles.

636 const didRenderTooFewHooks =

@@ -645,7 +708,13 @@ function finishRenderingHooks(current: Fiber | null, workInProgress: Fiber) {

708 if (checkIfUseWrappedInTryCatch()) {

709 const componentName =

710 getComponentNameFromFiber(workInProgress) || 'Unknown';

648 - if (!didWarnAboutUseWrappedInTryCatch.has(componentName)) {

711 + if (

712 + !didWarnAboutUseWrappedInTryCatch.has(componentName) &&

713 + // This warning also fires if you suspend with `use` inside an

714 + // async component. Since we warn for that above, we'll silence this

715 + // second warning by checking here.

716 + !didWarnAboutAsyncClientComponent.has(componentName)

717 + ) {

718 didWarnAboutUseWrappedInTryCatch.add(componentName);

719 console.error(

720 '`use` was called from inside a try/catch block. This is not allowed ' +

@@ -683,7 +752,7 @@ export function replaySuspendedComponentWithHooks<Props, SecondArg>(

752 props,

753 secondArg,

754 );

686 - finishRenderingHooks(current, workInProgress);

755 + finishRenderingHooks(current, workInProgress, Component);

756 return children;

757 }

758

packages/react-reconciler/src/ReactFiberThenable.js

+30 -10

@@ -94,6 +94,7 @@ export function trackUsedThenable<T>(

94 }

95 case 'rejected': {

96 const rejectedError = thenable.reason;

97 + checkIfUseWrappedInAsyncCatch(rejectedError);

98 throw rejectedError;

99 }

100 default: {

@@ -149,17 +150,19 @@ export function trackUsedThenable<T>(

150 }

151 },

152 );

152 - }

153

154 - // Check one more time in case the thenable resolved synchronously.

155 - switch (thenable.status) {

156 - case 'fulfilled': {

157 - const fulfilledThenable: FulfilledThenable<T> = (thenable: any);

158 - return fulfilledThenable.value;

159 - }

160 - case 'rejected': {

161 - const rejectedThenable: RejectedThenable<T> = (thenable: any);

162 - throw rejectedThenable.reason;

154 + // Check one more time in case the thenable resolved synchronously.

155 + switch (thenable.status) {

156 + case 'fulfilled': {

157 + const fulfilledThenable: FulfilledThenable<T> = (thenable: any);

158 + return fulfilledThenable.value;

159 + }

160 + case 'rejected': {

161 + const rejectedThenable: RejectedThenable<T> = (thenable: any);

162 + const rejectedError = rejectedThenable.reason;

163 + checkIfUseWrappedInAsyncCatch(rejectedError);

164 + throw rejectedError;

165 + }

166 }

167 }

168

@@ -223,3 +226,20 @@ export function checkIfUseWrappedInTryCatch(): boolean {

226 }

227 return false;

228 }

229 +

230 +export function checkIfUseWrappedInAsyncCatch(rejectedReason: any) {

231 + // This check runs in prod, too, because it prevents a more confusing

232 + // downstream error, where SuspenseException is caught by a promise and

233 + // thrown asynchronously.

234 + // TODO: Another way to prevent SuspenseException from leaking into an async

235 + // execution context is to check the dispatcher every time `use` is called,

236 + // or some equivalent. That might be preferable for other reasons, too, since

237 + // it matches how we prevent similar mistakes for other hooks.

238 + if (rejectedReason === SuspenseException) {

239 + throw new Error(

240 + 'Hooks are not supported inside an async component. This ' +

241 + "error is often caused by accidentally adding `'use client'` " +

242 + 'to a module that was originally written for the server.',

243 + );

244 + }

245 +}

packages/react-reconciler/src/__tests__/ReactUse-test.js

+70 -14

@@ -1639,13 +1639,20 @@ describe('ReactUse', () => {

1639 }

1640

1641 const root = ReactNoop.createRoot();

1642 - await act(() => {

1643 - root.render(

1644 - <ErrorBoundary>

1645 - <AsyncClientComponent />

1646 - </ErrorBoundary>,

1647 - );

1648 - });

1642 + await expect(async () => {

1643 + await act(() => {

1644 + root.render(

1645 + <ErrorBoundary>

1646 + <AsyncClientComponent />

1647 + </ErrorBoundary>,

1648 + );

1649 + });

1650 + }).toErrorDev([

1651 + 'async/await is not yet supported in Client Components, only ' +

1652 + 'Server Components. This error is often caused by accidentally ' +

1653 + "adding `'use client'` to a module that was originally written " +

1654 + 'for the server.',

1655 + ]);

1656 assertLog([

1657 'async/await is not yet supported in Client Components, only Server ' +

1658 'Components. This error is often caused by accidentally adding ' +

@@ -1685,13 +1692,20 @@ describe('ReactUse', () => {

1692 }

1693

1694 const root = ReactNoop.createRoot();

1688 - await act(() => {

1689 - root.render(

1690 - <ErrorBoundary>

1691 - <AsyncClientComponent />

1692 - </ErrorBoundary>,

1693 - );

1694 - });

1695 + await expect(async () => {

1696 + await act(() => {

1697 + root.render(

1698 + <ErrorBoundary>

1699 + <AsyncClientComponent />

1700 + </ErrorBoundary>,

1701 + );

1702 + });

1703 + }).toErrorDev([

1704 + 'async/await is not yet supported in Client Components, only ' +

1705 + 'Server Components. This error is often caused by accidentally ' +

1706 + "adding `'use client'` to a module that was originally written " +

1707 + 'for the server.',

1708 + ]);

1709 assertLog([

1710 'async/await is not yet supported in Client Components, only Server ' +

1711 'Components. This error is often caused by accidentally adding ' +

@@ -1709,4 +1723,46 @@ describe('ReactUse', () => {

1723 'the server.',

1724 );

1725 });

1726 +

1727 + test('warn if async client component calls a hook (e.g. useState)', async () => {

1728 + async function AsyncClientComponent() {

1729 + useState();

1730 + return <Text text="Hi" />;

1731 + }

1732 +

1733 + const root = ReactNoop.createRoot();

1734 + await expect(async () => {

1735 + await act(() => {

1736 + startTransition(() => {

1737 + root.render(<AsyncClientComponent />);

1738 + });

1739 + });

1740 + }).toErrorDev([

1741 + 'Hooks are not supported inside an async component. This ' +

1742 + "error is often caused by accidentally adding `'use client'` " +

1743 + 'to a module that was originally written for the server.',

1744 + ]);

1745 + });

1746 +

1747 + test('warn if async client component calls a hook (e.g. use)', async () => {

1748 + const promise = Promise.resolve();

1749 +

1750 + async function AsyncClientComponent() {

1751 + use(promise);

1752 + return <Text text="Hi" />;

1753 + }

1754 +

1755 + const root = ReactNoop.createRoot();

1756 + await expect(async () => {

1757 + await act(() => {

1758 + startTransition(() => {

1759 + root.render(<AsyncClientComponent />);

1760 + });

1761 + });

1762 + }).toErrorDev([

1763 + 'Hooks are not supported inside an async component. This ' +

1764 + "error is often caused by accidentally adding `'use client'` " +

1765 + 'to a module that was originally written for the server.',

1766 + ]);

1767 + });

1768 });

packages/shared/ReactComponentStackFrame.js

+9 -1

@@ -132,7 +132,15 @@ export function describeNativeComponentFrame(

132 // TODO(luna): This will currently only throw if the function component

133 // tries to access React/ReactDOM/props. We should probably make this throw

134 // in simple components too

135 - fn();

135 + const maybePromise = fn();

136 +

137 + // If the function component returns a promise, it's likely an async

138 + // component, which we don't yet support. Attach a noop catch handler to

139 + // silence the error.

140 + // TODO: Implement component stacks for async client components?

141 + if (maybePromise && typeof maybePromise.catch === 'function') {

142 + maybePromise.catch(() => {});

143 + }

144 }

145 } catch (sample) {

146 // This is inlined manually because closure doesn't do it for us.

scripts/error-codes/codes.json

+2 -1

@@ -467,5 +467,6 @@

467 "479": "Cannot update optimistic state while rendering.",

468 "480": "File/Blob fields are not yet supported in progressive forms. It probably means you are closing over binary data or FormData in a Server Action.",

469 "481": "Tried to encode a Server Action from a different instance than the encoder is from. This is a bug in React.",

470 - "482": "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."

470 + "482": "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.",

471 + "483": "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."

472 }