bugfix: fix eager state miss https://github.com/facebook/react/issues…

[HHsomeHand]

…/34061

Summary

I open a issue to explain this: #34061

==== the issue content ======

import React, { useState } from 'react';

export function App(props) {
  console.log('App');
  return <Child0 />;
}

function Child0(props) {
  let [state, setState] = useState(0);
  console.log('child0', state);
  return (
    <div onClick={() => setState(1)}>
      child0
      <Child1 />
    </div>
  );
}

function Child1(props) {
  console.log('child1');
  console.log('=======');
  return <div>child1</div>;
}

console:

App 
child0 0
child1 
=======  (first click)
child0 1
child1 
======= (second click) 
child0 1

(rest click: noop, eager state)

Strange, why is child0 1 printed one more time here?

Isn't there eager state? If the state hasn't changed, it shouldn't re-render, right?

I didn't use StrictMode

I debug react:

 function dispatchSetStateInternal(fiber, queue, action, lane) {
      var update = {
        lane: lane,
        revertLane: 0,
        action: action,
        hasEagerState: !1,
        eagerState: null,
        next: null
      };
      if (isRenderPhaseUpdate(fiber)) enqueueRenderPhaseUpdate(queue, update);
      else {
        var alternate = fiber.alternate;
        if (
          0 === fiber.lanes &&
          (null === alternate || 0 === alternate.lanes) &&
          ((alternate = queue.lastRenderedReducer), null !== alternate)
        ) {
          var prevDispatcher = ReactSharedInternals.H;
          ReactSharedInternals.H = InvalidNestedHooksDispatcherOnUpdateInDEV;
          try {
            var currentState = queue.lastRenderedState,
              eagerState = alternate(currentState, action);
            update.hasEagerState = !0;
            update.eagerState = eagerState;
            if (objectIs(eagerState, currentState))
              return (
                enqueueUpdate$1(fiber, queue, update, 0),
                null === workInProgressRoot &&
                  finishQueueingConcurrentUpdates(),
                !1
              );
          } catch (error) {
          } finally {
            ReactSharedInternals.H = prevDispatcher;
          }
        }
        action = enqueueConcurrentHookUpdate(fiber, queue, update, lane);
        if (null !== action)
          return (
            scheduleUpdateOnFiber(action, fiber, lane),
            entangleTransitionUpdate(action, queue, lane),
            !0
          );
      }
      return !1;
    }

I'm not using concurrent rendering either—so why does the 0 === fiber.lanes check fail?

Isn't fiber.lanes supposed to be cleared after the update is finished?

======

How did you test this change?

very small change, I use yarn test to run tests on my code.

Then I build it with the following command:

node ./scripts/rollup/build.js react/index,react/jsx,react.react-server,react-dom/index,react-dom/client,react-dom/server,react-dom.react-server,react-dom-server.node,react-dom-server-legacy.node,scheduler,react-server-dom-webpack/ --type=NODE_DEV,ESM_PROD,NODE_ES2015

After building, I link the react and react-dom packages to a project created with create-react-app. I initially tried linking them to a Vite project, but Vite threw some errors that vite can't use commonJS package.

However, the create-react-app project also throws an error:

Uncaught TypeError: Cannot read properties of null (reading 'useState')
    at exports.useState (react.development.js:1222:1)
    at Child0 (App.js:10:1)
    at Object.react_stack_bottom_frame (react-dom-client.development.js:28836:1)
    at renderWithHooks (react-dom-client.development.js:7742:1)
    at updateFunctionComponent (react-dom-client.development.js:10173:1)
    at beginWork (react-dom-client.development.js:11838:1)
    at runWithFiberInDEV (react-dom-client.development.js:990:1)
    at performUnitOfWork (react-dom-client.development.js:19212:1)
    at workLoopSync (react-dom-client.development.js:19042:1)
    at renderRootSync (react-dom-client.development.js:19023:1)

I didn’t modify useState, so this is really strange. Maybe I built it incorrectly?

but I run yarn test, only a few test didn't pass(17), like original project that i didn't modify anything.

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