Best JavaScript code snippet using playwright-internal
ReactFiberWorkLoop.new.js
Source:ReactFiberWorkLoop.new.js  
...1302}1303function popDispatcher(prevDispatcher) {1304  ReactCurrentDispatcher.current = prevDispatcher;1305}1306function pushInteractions(root) {1307  if (enableSchedulerTracing) {1308    const prevInteractions: Set<Interaction> | null = __interactionsRef.current;1309    __interactionsRef.current = root.memoizedInteractions;1310    return prevInteractions;1311  }1312  return null;1313}1314function popInteractions(prevInteractions) {1315  if (enableSchedulerTracing) {1316    __interactionsRef.current = prevInteractions;1317  }1318}1319export function markCommitTimeOfFallback() {1320  globalMostRecentFallbackTime = now();1321}1322export function markSkippedUpdateLanes(lane: Lane | Lanes): void {1323  workInProgressRootSkippedLanes = mergeLanes(1324    lane,1325    workInProgressRootSkippedLanes,1326  );1327}1328export function renderDidSuspend(): void {1329  if (workInProgressRootExitStatus === RootIncomplete) {1330    workInProgressRootExitStatus = RootSuspended;1331  }1332}1333export function renderDidSuspendDelayIfPossible(): void {1334  if (1335    workInProgressRootExitStatus === RootIncomplete ||1336    workInProgressRootExitStatus === RootSuspended1337  ) {1338    workInProgressRootExitStatus = RootSuspendedWithDelay;1339  }1340  // Check if there are updates that we skipped tree that might have unblocked1341  // this render.1342  if (1343    workInProgressRoot !== null &&1344    (includesNonIdleWork(workInProgressRootSkippedLanes) ||1345      includesNonIdleWork(workInProgressRootUpdatedLanes))1346  ) {1347    // Mark the current render as suspended so that we switch to working on1348    // the updates that were skipped. Usually we only suspend at the end of1349    // the render phase.1350    // TODO: We should probably always mark the root as suspended immediately1351    // (inside this function), since by suspending at the end of the render1352    // phase introduces a potential mistake where we suspend lanes that were1353    // pinged or updated while we were rendering.1354    markRootSuspended(workInProgressRoot, workInProgressRootRenderLanes);1355  }1356}1357export function renderDidError() {1358  if (workInProgressRootExitStatus !== RootCompleted) {1359    workInProgressRootExitStatus = RootErrored;1360  }1361}1362// Called during render to determine if anything has suspended.1363// Returns false if we're not sure.1364export function renderHasNotSuspendedYet(): boolean {1365  // If something errored or completed, we can't really be sure,1366  // so those are false.1367  return workInProgressRootExitStatus === RootIncomplete;1368}1369function renderRootSync(root: FiberRoot, lanes: Lanes) {1370  const prevExecutionContext = executionContext;1371  executionContext |= RenderContext;1372  const prevDispatcher = pushDispatcher();1373  // If the root or lanes have changed, throw out the existing stack1374  // and prepare a fresh one. Otherwise we'll continue where we left off.1375  if (workInProgressRoot !== root || workInProgressRootRenderLanes !== lanes) {1376    prepareFreshStack(root, lanes);1377    startWorkOnPendingInteractions(root, lanes);1378  }1379  const prevInteractions = pushInteractions(root);1380  if (__DEV__) {1381    if (enableDebugTracing) {1382      logRenderStarted(lanes);1383    }1384  }1385  if (enableSchedulingProfiler) {1386    markRenderStarted(lanes);1387  }1388  do {1389    try {1390      workLoopSync();1391      break;1392    } catch (thrownValue) {1393      handleError(root, thrownValue);1394    }1395  } while (true);1396  resetContextDependencies();1397  if (enableSchedulerTracing) {1398    popInteractions(((prevInteractions: any): Set<Interaction>));1399  }1400  executionContext = prevExecutionContext;1401  popDispatcher(prevDispatcher);1402  if (workInProgress !== null) {1403    // This is a sync render, so we should have finished the whole tree.1404    invariant(1405      false,1406      'Cannot commit an incomplete root. This error is likely caused by a ' +1407        'bug in React. Please file an issue.',1408    );1409  }1410  if (__DEV__) {1411    if (enableDebugTracing) {1412      logRenderStopped();1413    }1414  }1415  if (enableSchedulingProfiler) {1416    markRenderStopped();1417  }1418  // Set this to null to indicate there's no in-progress render.1419  workInProgressRoot = null;1420  workInProgressRootRenderLanes = NoLanes;1421  return workInProgressRootExitStatus;1422}1423// The work loop is an extremely hot path. Tell Closure not to inline it.1424/** @noinline */1425function workLoopSync() {1426  // Already timed out, so perform work without checking if we need to yield.1427  while (workInProgress !== null) {1428    performUnitOfWork(workInProgress);1429  }1430}1431function renderRootConcurrent(root: FiberRoot, lanes: Lanes) {1432  const prevExecutionContext = executionContext;1433  executionContext |= RenderContext;1434  const prevDispatcher = pushDispatcher();1435  // If the root or lanes have changed, throw out the existing stack1436  // and prepare a fresh one. Otherwise we'll continue where we left off.1437  if (workInProgressRoot !== root || workInProgressRootRenderLanes !== lanes) {1438    resetRenderTimer();1439    prepareFreshStack(root, lanes);1440    startWorkOnPendingInteractions(root, lanes);1441  }1442  const prevInteractions = pushInteractions(root);1443  if (__DEV__) {1444    if (enableDebugTracing) {1445      logRenderStarted(lanes);1446    }1447  }1448  if (enableSchedulingProfiler) {1449    markRenderStarted(lanes);1450  }1451  do {1452    try {1453      workLoopConcurrent();1454      break;1455    } catch (thrownValue) {1456      handleError(root, thrownValue);1457    }1458  } while (true);1459  resetContextDependencies();1460  if (enableSchedulerTracing) {1461    popInteractions(((prevInteractions: any): Set<Interaction>));1462  }1463  popDispatcher(prevDispatcher);1464  executionContext = prevExecutionContext;1465  if (__DEV__) {1466    if (enableDebugTracing) {1467      logRenderStopped();1468    }1469  }1470  // Check if the tree has completed.1471  if (workInProgress !== null) {1472    // Still work remaining.1473    if (enableSchedulingProfiler) {1474      markRenderYielded();1475    }1476    return RootIncomplete;1477  } else {1478    // Completed the tree.1479    if (enableSchedulingProfiler) {1480      markRenderStopped();1481    }1482    // Set this to null to indicate there's no in-progress render.1483    workInProgressRoot = null;1484    workInProgressRootRenderLanes = NoLanes;1485    // Return the final exit status.1486    return workInProgressRootExitStatus;1487  }1488}1489/** @noinline */1490function workLoopConcurrent() {1491  // Perform work until Scheduler asks us to yield1492  while (workInProgress !== null && !shouldYield()) {1493    performUnitOfWork(workInProgress);1494  }1495}1496function performUnitOfWork(unitOfWork: Fiber): void {1497  // The current, flushed, state of this fiber is the alternate. Ideally1498  // nothing should rely on this, but relying on it here means that we don't1499  // need an additional field on the work in progress.1500  const current = unitOfWork.alternate;1501  setCurrentDebugFiberInDEV(unitOfWork);1502  let next;1503  if (enableProfilerTimer && (unitOfWork.mode & ProfileMode) !== NoMode) {1504    startProfilerTimer(unitOfWork);1505    next = beginWork(current, unitOfWork, subtreeRenderLanes);1506    stopProfilerTimerIfRunningAndRecordDelta(unitOfWork, true);1507  } else {1508    next = beginWork(current, unitOfWork, subtreeRenderLanes);1509  }1510  resetCurrentDebugFiberInDEV();1511  unitOfWork.memoizedProps = unitOfWork.pendingProps;1512  if (next === null) {1513    // If this doesn't spawn new work, complete the current work.1514    completeUnitOfWork(unitOfWork);1515  } else {1516    workInProgress = next;1517  }1518  ReactCurrentOwner.current = null;1519}1520function completeUnitOfWork(unitOfWork: Fiber): void {1521  // Attempt to complete the current unit of work, then move to the next1522  // sibling. If there are no more siblings, return to the parent fiber.1523  let completedWork = unitOfWork;1524  do {1525    // The current, flushed, state of this fiber is the alternate. Ideally1526    // nothing should rely on this, but relying on it here means that we don't1527    // need an additional field on the work in progress.1528    const current = completedWork.alternate;1529    const returnFiber = completedWork.return;1530    // Check if the work completed or if something threw.1531    if ((completedWork.flags & Incomplete) === NoFlags) {1532      setCurrentDebugFiberInDEV(completedWork);1533      let next;1534      if (1535        !enableProfilerTimer ||1536        (completedWork.mode & ProfileMode) === NoMode1537      ) {1538        next = completeWork(current, completedWork, subtreeRenderLanes);1539      } else {1540        startProfilerTimer(completedWork);1541        next = completeWork(current, completedWork, subtreeRenderLanes);1542        // Update render duration assuming we didn't error.1543        stopProfilerTimerIfRunningAndRecordDelta(completedWork, false);1544      }1545      resetCurrentDebugFiberInDEV();1546      if (next !== null) {1547        // Completing this fiber spawned new work. Work on that next.1548        workInProgress = next;1549        return;1550      }1551    } else {1552      // This fiber did not complete because something threw. Pop values off1553      // the stack without entering the complete phase. If this is a boundary,1554      // capture values if possible.1555      const next = unwindWork(completedWork, subtreeRenderLanes);1556      // Because this fiber did not complete, don't reset its expiration time.1557      if (next !== null) {1558        // If completing this work spawned new work, do that next. We'll come1559        // back here again.1560        // Since we're restarting, remove anything that is not a host effect1561        // from the effect tag.1562        next.flags &= HostEffectMask;1563        workInProgress = next;1564        return;1565      }1566      if (1567        enableProfilerTimer &&1568        (completedWork.mode & ProfileMode) !== NoMode1569      ) {1570        // Record the render duration for the fiber that errored.1571        stopProfilerTimerIfRunningAndRecordDelta(completedWork, false);1572        // Include the time spent working on failed children before continuing.1573        let actualDuration = completedWork.actualDuration;1574        let child = completedWork.child;1575        while (child !== null) {1576          actualDuration += child.actualDuration;1577          child = child.sibling;1578        }1579        completedWork.actualDuration = actualDuration;1580      }1581      if (returnFiber !== null) {1582        // Mark the parent fiber as incomplete1583        returnFiber.flags |= Incomplete;1584        returnFiber.subtreeFlags = NoFlags;1585        returnFiber.deletions = null;1586      }1587    }1588    const siblingFiber = completedWork.sibling;1589    if (siblingFiber !== null) {1590      // If there is more work to do in this returnFiber, do that next.1591      workInProgress = siblingFiber;1592      return;1593    }1594    // Otherwise, return to the parent1595    completedWork = returnFiber;1596    // Update the next thing we're working on in case something throws.1597    workInProgress = completedWork;1598  } while (completedWork !== null);1599  // We've reached the root.1600  if (workInProgressRootExitStatus === RootIncomplete) {1601    workInProgressRootExitStatus = RootCompleted;1602  }1603}1604function commitRoot(root) {1605  const renderPriorityLevel = getCurrentPriorityLevel();1606  runWithPriority(1607    ImmediateSchedulerPriority,1608    commitRootImpl.bind(null, root, renderPriorityLevel),1609  );1610  return null;1611}1612function commitRootImpl(root, renderPriorityLevel) {1613  do {1614    // `flushPassiveEffects` will call `flushSyncUpdateQueue` at the end, which1615    // means `flushPassiveEffects` will sometimes result in additional1616    // passive effects. So we need to keep flushing in a loop until there are1617    // no more pending effects.1618    // TODO: Might be better if `flushPassiveEffects` did not automatically1619    // flush synchronous work at the end, to avoid factoring hazards like this.1620    flushPassiveEffects();1621  } while (rootWithPendingPassiveEffects !== null);1622  flushRenderPhaseStrictModeWarningsInDEV();1623  invariant(1624    (executionContext & (RenderContext | CommitContext)) === NoContext,1625    'Should not already be working.',1626  );1627  const finishedWork = root.finishedWork;1628  const lanes = root.finishedLanes;1629  if (__DEV__) {1630    if (enableDebugTracing) {1631      logCommitStarted(lanes);1632    }1633  }1634  if (enableSchedulingProfiler) {1635    markCommitStarted(lanes);1636  }1637  // 没æéè¦æ´æ°çFiberèç¹1638  if (finishedWork === null) {1639    if (__DEV__) {1640      if (enableDebugTracing) {1641        logCommitStopped();1642      }1643    }1644    if (enableSchedulingProfiler) {1645      markCommitStopped();1646    }1647    return null;1648  }1649  root.finishedWork = null;1650  root.finishedLanes = NoLanes;1651  invariant(1652    finishedWork !== root.current,1653    'Cannot commit the same tree as before. This error is likely caused by ' +1654      'a bug in React. Please file an issue.',1655  );1656  // commitRoot never returns a continuation; it always finishes synchronously.1657  // So we can clear these now to allow a new callback to be scheduled.1658  root.callbackNode = null;1659  // Update the first and last pending times on this root. The new first1660  // pending time is whatever is left on the root fiber.1661  // åå¹¶ææçéé1662  let remainingLanes = mergeLanes(finishedWork.lanes, finishedWork.childLanes);1663  markRootFinished(root, remainingLanes);1664  // Clear already finished discrete updates in case that a later call of1665  // `flushDiscreteUpdates` starts a useless render pass which may cancels1666  // a scheduled timeout.1667  if (rootsWithPendingDiscreteUpdates !== null) {1668    if (1669      !hasDiscreteLanes(remainingLanes) &&1670      rootsWithPendingDiscreteUpdates.has(root)1671    ) {1672      rootsWithPendingDiscreteUpdates.delete(root);1673    }1674  }1675  // è¯´ææ¬æ¬¡æ´æ°å·²ç»å®æäºï¼å°ä¸äºåééç½®1676  if (root === workInProgressRoot) {1677    // We can reset these now that they are finished.1678    workInProgressRoot = null;1679    workInProgress = null;1680    workInProgressRootRenderLanes = NoLanes;1681  } else {1682    // This indicates that the last root we worked on is not the same one that1683    // we're committing now. This most commonly happens when a suspended root1684    // times out.1685  }1686  // Check if there are any effects in the whole tree.1687  // TODO: This is left over from the effect list implementation, where we had1688  // to check for the existence of `firstEffect` to satsify Flow. I think the1689  // only other reason this optimization exists is because it affects profiling.1690  // Reconsider whether this is necessary.1691  const subtreeHasEffects =1692    (finishedWork.subtreeFlags &1693      (BeforeMutationMask | MutationMask | LayoutMask | PassiveMask)) !==1694    NoFlags;1695  const rootHasEffect =1696    (finishedWork.flags &1697      (BeforeMutationMask | MutationMask | LayoutMask | PassiveMask)) !==1698    NoFlags;1699    // æéè¦å¤ççå¯ä½ç¨1700  if (subtreeHasEffects || rootHasEffect) {1701    let previousLanePriority;1702    if (decoupleUpdatePriorityFromScheduler) {1703      previousLanePriority = getCurrentUpdateLanePriority();1704      setCurrentUpdateLanePriority(SyncLanePriority);1705    }1706    // 设置æ§è¡ä¸ä¸æ1707    const prevExecutionContext = executionContext;1708    executionContext |= CommitContext;1709    const prevInteractions = pushInteractions(root);1710    // Reset this to null before calling lifecycles1711    ReactCurrentOwner.current = null;1712    // The commit phase is broken into several sub-phases. We do a separate pass1713    // of the effect list for each phase: all mutation effects come before all1714    // layout effects, and so on.1715    // The first phase a "before mutation" phase. We use this phase to read the1716    // state of the host tree right before we mutate it. This is where1717    // getSnapshotBeforeUpdate is called.1718    focusedInstanceHandle = prepareForCommit(root.containerInfo);1719    shouldFireAfterActiveInstanceBlur = false;1720    commitBeforeMutationEffects(finishedWork);1721    // We no longer need to track the active instance fiber1722    focusedInstanceHandle = null;1723    if (enableProfilerTimer) {1724      // Mark the current commit time to be shared by all Profilers in this1725      // batch. This enables them to be grouped later.1726      recordCommitTime();1727    }1728    // æDOMå
素渲æå°é¡µé¢ä¸1729    // The next phase is the mutation phase, where we mutate the host tree.1730    commitMutationEffects(finishedWork, root, renderPriorityLevel);1731    if (shouldFireAfterActiveInstanceBlur) {1732      afterActiveInstanceBlur();1733    }1734    resetAfterCommit(root.containerInfo);1735    // The work-in-progress tree is now the current tree. This must come after1736    // the mutation phase, so that the previous tree is still current during1737    // componentWillUnmount, but before the layout phase, so that the finished1738    // work is current during componentDidMount/Update.1739    // 卿¤ä¹åï¼root.current æåäºwork-in-progress tree1740    root.current = finishedWork;1741    // The next phase is the layout phase, where we call effects that read1742    // the host tree after it's been mutated. The idiomatic use case for this is1743    // layout, but class component lifecycles also fire here for legacy reasons.1744    if (__DEV__) {1745      if (enableDebugTracing) {1746        logLayoutEffectsStarted(lanes);1747      }1748    }1749    if (enableSchedulingProfiler) {1750      markLayoutEffectsStarted(lanes);1751    }1752    if (__DEV__) {1753      setCurrentDebugFiberInDEV(finishedWork);1754      invokeGuardedCallback(1755        null,1756        recursivelyCommitLayoutEffects,1757        null,1758        finishedWork,1759        root,1760      );1761      if (hasCaughtError()) {1762        const error = clearCaughtError();1763        captureCommitPhaseErrorOnRoot(finishedWork, finishedWork, error);1764      }1765      resetCurrentDebugFiberInDEV();1766    } else {1767      try {1768        recursivelyCommitLayoutEffects(finishedWork, root);1769      } catch (error) {1770        captureCommitPhaseErrorOnRoot(finishedWork, finishedWork, error);1771      }1772    }1773    if (__DEV__) {1774      if (enableDebugTracing) {1775        logLayoutEffectsStopped();1776      }1777    }1778    if (enableSchedulingProfiler) {1779      markLayoutEffectsStopped();1780    }1781    // If there are pending passive effects, schedule a callback to process them.1782    if (1783      (finishedWork.subtreeFlags & PassiveMask) !== NoFlags ||1784      (finishedWork.flags & PassiveMask) !== NoFlags1785    ) {1786      if (!rootDoesHavePassiveEffects) {1787        rootDoesHavePassiveEffects = true;1788        scheduleCallback(NormalSchedulerPriority, () => {1789          flushPassiveEffects();1790          return null;1791        });1792      }1793    }1794    // Tell Scheduler to yield at the end of the frame, so the browser has an1795    // opportunity to paint.1796    requestPaint();1797    if (enableSchedulerTracing) {1798      popInteractions(((prevInteractions: any): Set<Interaction>));1799    }1800    executionContext = prevExecutionContext;1801    if (decoupleUpdatePriorityFromScheduler && previousLanePriority != null) {1802      // Reset the priority to the previous non-sync value.1803      setCurrentUpdateLanePriority(previousLanePriority);1804    }1805  } else {1806    // No effects.1807    root.current = finishedWork;1808    // Measure these anyway so the flamegraph explicitly shows that there were1809    // no effects.1810    // TODO: Maybe there's a better way to report this.1811    if (enableProfilerTimer) {1812      recordCommitTime();1813    }1814  }1815  const rootDidHavePassiveEffects = rootDoesHavePassiveEffects;1816  if (rootDoesHavePassiveEffects) {1817    // This commit has passive effects. Stash a reference to them. But don't1818    // schedule a callback until after flushing layout work.1819    rootDoesHavePassiveEffects = false;1820    rootWithPendingPassiveEffects = root;1821    pendingPassiveEffectsLanes = lanes;1822    pendingPassiveEffectsRenderPriority = renderPriorityLevel;1823  }1824  // Read this again, since an effect might have updated it1825  remainingLanes = root.pendingLanes;1826  // Check if there's remaining work on this root1827  if (remainingLanes !== NoLanes) {1828    if (enableSchedulerTracing) {1829      if (spawnedWorkDuringRender !== null) {1830        const expirationTimes = spawnedWorkDuringRender;1831        spawnedWorkDuringRender = null;1832        for (let i = 0; i < expirationTimes.length; i++) {1833          scheduleInteractions(1834            root,1835            expirationTimes[i],1836            root.memoizedInteractions,1837          );1838        }1839      }1840      schedulePendingInteractions(root, remainingLanes);1841    }1842  } else {1843    // If there's no remaining work, we can clear the set of already failed1844    // error boundaries.1845    legacyErrorBoundariesThatAlreadyFailed = null;1846  }1847  if (__DEV__ && enableDoubleInvokingEffects) {1848    if (!rootDidHavePassiveEffects) {1849      commitDoubleInvokeEffectsInDEV(root.current, false);1850    }1851  }1852  if (enableSchedulerTracing) {1853    if (!rootDidHavePassiveEffects) {1854      // If there are no passive effects, then we can complete the pending interactions.1855      // Otherwise, we'll wait until after the passive effects are flushed.1856      // Wait to do this until after remaining work has been scheduled,1857      // so that we don't prematurely signal complete for interactions when there's e.g. hidden work.1858      finishPendingInteractions(root, lanes);1859    }1860  }1861  if (remainingLanes === SyncLane) {1862    // Count the number of times the root synchronously re-renders without1863    // finishing. If there are too many, it indicates an infinite update loop.1864    if (root === rootWithNestedUpdates) {1865      nestedUpdateCount++;1866    } else {1867      nestedUpdateCount = 0;1868      rootWithNestedUpdates = root;1869    }1870  } else {1871    nestedUpdateCount = 0;1872  }1873  onCommitRootDevTools(finishedWork.stateNode, renderPriorityLevel);1874  if (__DEV__) {1875    onCommitRootTestSelector();1876  }1877  // Always call this before exiting `commitRoot`, to ensure that any1878  // additional work on this root is scheduled.1879  ensureRootIsScheduled(root, now());1880  if (hasUncaughtError) {1881    hasUncaughtError = false;1882    const error = firstUncaughtError;1883    firstUncaughtError = null;1884    throw error;1885  }1886  if ((executionContext & LegacyUnbatchedContext) !== NoContext) {1887    if (__DEV__) {1888      if (enableDebugTracing) {1889        logCommitStopped();1890      }1891    }1892    if (enableSchedulingProfiler) {1893      markCommitStopped();1894    }1895    // This is a legacy edge case. We just committed the initial mount of1896    // a ReactDOM.render-ed root inside of batchedUpdates. The commit fired1897    // synchronously, but layout updates should be deferred until the end1898    // of the batch.1899    return null;1900  }1901  // If layout work was scheduled, flush it now.1902  flushSyncCallbackQueue();1903  if (__DEV__) {1904    if (enableDebugTracing) {1905      logCommitStopped();1906    }1907  }1908  if (enableSchedulingProfiler) {1909    markCommitStopped();1910  }1911  return null;1912}1913function commitBeforeMutationEffects(firstChild: Fiber) {1914  let fiber = firstChild;1915  while (fiber !== null) {1916    // å¤çéè¦å é¤çfiber autoFocusãblur é»è¾ã1917    if (fiber.deletions !== null) {1918      commitBeforeMutationEffectsDeletions(fiber.deletions);1919    }1920    // éå½è°ç¨å¤çåèç¹1921    if (fiber.child !== null) {1922      const primarySubtreeFlags = fiber.subtreeFlags & BeforeMutationMask;1923      if (primarySubtreeFlags !== NoFlags) {1924        commitBeforeMutationEffects(fiber.child);1925      }1926    }1927    if (__DEV__) {1928      setCurrentDebugFiberInDEV(fiber);1929      invokeGuardedCallback(null, commitBeforeMutationEffectsImpl, null, fiber);1930      if (hasCaughtError()) {1931        const error = clearCaughtError();1932        captureCommitPhaseError(fiber, fiber.return, error);1933      }1934      resetCurrentDebugFiberInDEV();1935    } else {1936      try {1937        // è°ç¨ getSnapshotBeforeUpdate çå½å¨æ1938        // 弿¥è°åº¦useEffect1939        commitBeforeMutationEffectsImpl(fiber);1940      } catch (error) {1941        captureCommitPhaseError(fiber, fiber.return, error);1942      }1943    }1944    // è¿åå
å¼èç¹ï¼æ¥ç循ç¯1945    fiber = fiber.sibling;1946  }1947}1948function commitBeforeMutationEffectsImpl(fiber: Fiber) {1949  const current = fiber.alternate;1950  const flags = fiber.flags;1951  if (!shouldFireAfterActiveInstanceBlur && focusedInstanceHandle !== null) {1952    // Check to see if the focused element was inside of a hidden (Suspense) subtree.1953    // TODO: Move this out of the hot path using a dedicated effect tag.1954    if (1955      fiber.tag === SuspenseComponent &&1956      isSuspenseBoundaryBeingHidden(current, fiber) &&1957      doesFiberContain(fiber, focusedInstanceHandle)1958    ) {1959      shouldFireAfterActiveInstanceBlur = true;1960      beforeActiveInstanceBlur();1961    }1962  }1963  if ((flags & Snapshot) !== NoFlags) {1964    setCurrentDebugFiberInDEV(fiber);1965    // è°ç¨ getSnapshotBeforeUpdate çå½å¨æ1966    commitBeforeMutationEffectOnFiber(current, fiber);1967    resetCurrentDebugFiberInDEV();1968  }1969  // è°åº¦useEffect1970  if ((flags & Passive) !== NoFlags) {1971    // If there are passive effects, schedule a callback to flush at1972    // the earliest opportunity.1973    if (!rootDoesHavePassiveEffects) {1974      rootDoesHavePassiveEffects = true;1975      scheduleCallback(NormalSchedulerPriority, () => {1976        flushPassiveEffects();1977        return null;1978      });1979    }1980  }1981}1982function commitBeforeMutationEffectsDeletions(deletions: Array<Fiber>) {1983  for (let i = 0; i < deletions.length; i++) {1984    const fiber = deletions[i];1985    // TODO (effects) It would be nice to avoid calling doesFiberContain()1986    // Maybe we can repurpose one of the subtreeFlags positions for this instead?1987    // Use it to store which part of the tree the focused instance is in?1988    // This assumes we can safely determine that instance during the "render" phase.1989    if (doesFiberContain(fiber, ((focusedInstanceHandle: any): Fiber))) {1990      shouldFireAfterActiveInstanceBlur = true;1991      beforeActiveInstanceBlur();1992    }1993  }1994}1995function commitMutationEffects(1996  firstChild: Fiber,1997  root: FiberRoot,1998  renderPriorityLevel: ReactPriorityLevel,1999) {2000  let fiber = firstChild;2001  while (fiber !== null) {2002    const deletions = fiber.deletions;2003    if (deletions !== null) {2004      commitMutationEffectsDeletions(2005        deletions,2006        fiber,2007        root,2008        renderPriorityLevel,2009      );2010    }2011    if (fiber.child !== null) {2012      const mutationFlags = fiber.subtreeFlags & MutationMask;2013      if (mutationFlags !== NoFlags) {2014        commitMutationEffects(fiber.child, root, renderPriorityLevel);2015      }2016    }2017    if (__DEV__) {2018      setCurrentDebugFiberInDEV(fiber);2019      invokeGuardedCallback(2020        null,2021        commitMutationEffectsImpl,2022        null,2023        fiber,2024        root,2025        renderPriorityLevel,2026      );2027      if (hasCaughtError()) {2028        const error = clearCaughtError();2029        captureCommitPhaseError(fiber, fiber.return, error);2030      }2031      resetCurrentDebugFiberInDEV();2032    } else {2033      try {2034        commitMutationEffectsImpl(fiber, root, renderPriorityLevel);2035      } catch (error) {2036        captureCommitPhaseError(fiber, fiber.return, error);2037      }2038    }2039    fiber = fiber.sibling;2040  }2041}2042function commitMutationEffectsImpl(2043  fiber: Fiber,2044  root: FiberRoot,2045  renderPriorityLevel,2046) {2047  const flags = fiber.flags;2048  if (flags & ContentReset) {2049    commitResetTextContent(fiber);2050  }2051  if (flags & Ref) {2052    const current = fiber.alternate;2053    if (current !== null) {2054      commitDetachRef(current);2055    }2056    if (enableScopeAPI) {2057      // TODO: This is a temporary solution that allowed us to transition away from React Flare on www.2058      if (fiber.tag === ScopeComponent) {2059        commitAttachRef(fiber);2060      }2061    }2062  }2063  // The following switch statement is only concerned about placement,2064  // updates, and deletions. To avoid needing to add a case for every possible2065  // bitmap value, we remove the secondary effects from the effect tag and2066  // switch on that value.2067  const primaryFlags = flags & (Placement | Update | Hydrating);2068  switch (primaryFlags) {2069    case Placement: {2070      commitPlacement(fiber);2071      // Clear the "placement" from effect tag so that we know that this is2072      // inserted, before any life-cycles like componentDidMount gets called.2073      // TODO: findDOMNode doesn't rely on this any more but isMounted does2074      // and isMounted is deprecated anyway so we should be able to kill this.2075      fiber.flags &= ~Placement;2076      break;2077    }2078    case PlacementAndUpdate: {2079      // Placement2080      commitPlacement(fiber);2081      // Clear the "placement" from effect tag so that we know that this is2082      // inserted, before any life-cycles like componentDidMount gets called.2083      fiber.flags &= ~Placement;2084      // Update2085      const current = fiber.alternate;2086      commitWork(current, fiber);2087      break;2088    }2089    case Hydrating: {2090      fiber.flags &= ~Hydrating;2091      break;2092    }2093    case HydratingAndUpdate: {2094      fiber.flags &= ~Hydrating;2095      // Update2096      const current = fiber.alternate;2097      commitWork(current, fiber);2098      break;2099    }2100    case Update: {2101      const current = fiber.alternate;2102      commitWork(current, fiber);2103      break;2104    }2105  }2106}2107function commitMutationEffectsDeletions(2108  deletions: Array<Fiber>,2109  nearestMountedAncestor: Fiber,2110  root: FiberRoot,2111  renderPriorityLevel,2112) {2113  for (let i = 0; i < deletions.length; i++) {2114    const childToDelete = deletions[i];2115    if (__DEV__) {2116      invokeGuardedCallback(2117        null,2118        commitDeletion,2119        null,2120        root,2121        childToDelete,2122        nearestMountedAncestor,2123        renderPriorityLevel,2124      );2125      if (hasCaughtError()) {2126        const error = clearCaughtError();2127        captureCommitPhaseError(childToDelete, nearestMountedAncestor, error);2128      }2129    } else {2130      try {2131        commitDeletion(2132          root,2133          childToDelete,2134          nearestMountedAncestor,2135          renderPriorityLevel,2136        );2137      } catch (error) {2138        captureCommitPhaseError(childToDelete, nearestMountedAncestor, error);2139      }2140    }2141  }2142}2143export function schedulePassiveEffectCallback() {2144  if (!rootDoesHavePassiveEffects) {2145    rootDoesHavePassiveEffects = true;2146    scheduleCallback(NormalSchedulerPriority, () => {2147      flushPassiveEffects();2148      return null;2149    });2150  }2151}2152export function flushPassiveEffects(): boolean {2153  // Returns whether passive effects were flushed.2154  if (pendingPassiveEffectsRenderPriority !== NoSchedulerPriority) {2155    const priorityLevel =2156      pendingPassiveEffectsRenderPriority > NormalSchedulerPriority2157        ? NormalSchedulerPriority2158        : pendingPassiveEffectsRenderPriority;2159    pendingPassiveEffectsRenderPriority = NoSchedulerPriority;2160    if (decoupleUpdatePriorityFromScheduler) {2161      const previousLanePriority = getCurrentUpdateLanePriority();2162      try {2163        setCurrentUpdateLanePriority(2164          schedulerPriorityToLanePriority(priorityLevel),2165        );2166        return runWithPriority(priorityLevel, flushPassiveEffectsImpl);2167      } finally {2168        setCurrentUpdateLanePriority(previousLanePriority);2169      }2170    } else {2171      return runWithPriority(priorityLevel, flushPassiveEffectsImpl);2172    }2173  }2174  return false;2175}2176function flushPassiveMountEffects(root, firstChild: Fiber): void {2177  let fiber = firstChild;2178  while (fiber !== null) {2179    let prevProfilerOnStack = null;2180    if (enableProfilerTimer && enableProfilerCommitHooks) {2181      if (fiber.tag === Profiler) {2182        prevProfilerOnStack = nearestProfilerOnStack;2183        nearestProfilerOnStack = fiber;2184      }2185    }2186    const primarySubtreeFlags = fiber.subtreeFlags & PassiveMask;2187    if (fiber.child !== null && primarySubtreeFlags !== NoFlags) {2188      flushPassiveMountEffects(root, fiber.child);2189    }2190    if ((fiber.flags & Passive) !== NoFlags) {2191      if (__DEV__) {2192        setCurrentDebugFiberInDEV(fiber);2193        invokeGuardedCallback(2194          null,2195          commitPassiveMountOnFiber,2196          null,2197          root,2198          fiber,2199        );2200        if (hasCaughtError()) {2201          const error = clearCaughtError();2202          captureCommitPhaseError(fiber, fiber.return, error);2203        }2204        resetCurrentDebugFiberInDEV();2205      } else {2206        try {2207          commitPassiveMountOnFiber(root, fiber);2208        } catch (error) {2209          captureCommitPhaseError(fiber, fiber.return, error);2210        }2211      }2212    }2213    if (enableProfilerTimer && enableProfilerCommitHooks) {2214      if (fiber.tag === Profiler) {2215        // Bubble times to the next nearest ancestor Profiler.2216        // After we process that Profiler, we'll bubble further up.2217        if (prevProfilerOnStack !== null) {2218          prevProfilerOnStack.stateNode.passiveEffectDuration +=2219            fiber.stateNode.passiveEffectDuration;2220        }2221        nearestProfilerOnStack = prevProfilerOnStack;2222      }2223    }2224    fiber = fiber.sibling;2225  }2226}2227function flushPassiveUnmountEffects(firstChild: Fiber): void {2228  let fiber = firstChild;2229  while (fiber !== null) {2230    const deletions = fiber.deletions;2231    if (deletions !== null) {2232      for (let i = 0; i < deletions.length; i++) {2233        const fiberToDelete = deletions[i];2234        flushPassiveUnmountEffectsInsideOfDeletedTree(fiberToDelete, fiber);2235        // Now that passive effects have been processed, it's safe to detach lingering pointers.2236        detachFiberAfterEffects(fiberToDelete);2237      }2238    }2239    const child = fiber.child;2240    if (child !== null) {2241      // If any children have passive effects then traverse the subtree.2242      // Note that this requires checking subtreeFlags of the current Fiber,2243      // rather than the subtreeFlags/effectsTag of the first child,2244      // since that would not cover passive effects in siblings.2245      const passiveFlags = fiber.subtreeFlags & PassiveMask;2246      if (passiveFlags !== NoFlags) {2247        flushPassiveUnmountEffects(child);2248      }2249    }2250    const primaryFlags = fiber.flags & Passive;2251    if (primaryFlags !== NoFlags) {2252      setCurrentDebugFiberInDEV(fiber);2253      commitPassiveUnmountOnFiber(fiber);2254      resetCurrentDebugFiberInDEV();2255    }2256    fiber = fiber.sibling;2257  }2258}2259function flushPassiveUnmountEffectsInsideOfDeletedTree(2260  fiberToDelete: Fiber,2261  nearestMountedAncestor: Fiber,2262): void {2263  if ((fiberToDelete.subtreeFlags & PassiveStatic) !== NoFlags) {2264    // If any children have passive effects then traverse the subtree.2265    // Note that this requires checking subtreeFlags of the current Fiber,2266    // rather than the subtreeFlags/effectsTag of the first child,2267    // since that would not cover passive effects in siblings.2268    let child = fiberToDelete.child;2269    while (child !== null) {2270      flushPassiveUnmountEffectsInsideOfDeletedTree(2271        child,2272        nearestMountedAncestor,2273      );2274      child = child.sibling;2275    }2276  }2277  if ((fiberToDelete.flags & PassiveStatic) !== NoFlags) {2278    setCurrentDebugFiberInDEV(fiberToDelete);2279    commitPassiveUnmountInsideDeletedTreeOnFiber(2280      fiberToDelete,2281      nearestMountedAncestor,2282    );2283    resetCurrentDebugFiberInDEV();2284  }2285}2286function flushPassiveEffectsImpl() {2287  if (rootWithPendingPassiveEffects === null) {2288    return false;2289  }2290  const root = rootWithPendingPassiveEffects;2291  const lanes = pendingPassiveEffectsLanes;2292  rootWithPendingPassiveEffects = null;2293  pendingPassiveEffectsLanes = NoLanes;2294  invariant(2295    (executionContext & (RenderContext | CommitContext)) === NoContext,2296    'Cannot flush passive effects while already rendering.',2297  );2298  if (__DEV__) {2299    if (enableDebugTracing) {2300      logPassiveEffectsStarted(lanes);2301    }2302  }2303  if (enableSchedulingProfiler) {2304    markPassiveEffectsStarted(lanes);2305  }2306  if (__DEV__) {2307    isFlushingPassiveEffects = true;2308  }2309  const prevExecutionContext = executionContext;2310  executionContext |= CommitContext;2311  const prevInteractions = pushInteractions(root);2312  // It's important that ALL pending passive effect destroy functions are called2313  // before ANY passive effect create functions are called.2314  // Otherwise effects in sibling components might interfere with each other.2315  // e.g. a destroy function in one component may unintentionally override a ref2316  // value set by a create function in another component.2317  // Layout effects have the same constraint.2318  flushPassiveUnmountEffects(root.current);2319  flushPassiveMountEffects(root, root.current);2320  if (__DEV__) {2321    if (enableDebugTracing) {2322      logPassiveEffectsStopped();2323    }2324  }2325  if (enableSchedulingProfiler) {...ReactFiberWorkLoop.old.js
Source:ReactFiberWorkLoop.old.js  
...830  }831  function popDispatcher(prevDispatcher) {832    ReactCurrentDispatcher$2.current = prevDispatcher;833  }834  function pushInteractions(root) {835    {836      var prevInteractions = __interactionsRef.current;837      __interactionsRef.current = root.memoizedInteractions;838      return prevInteractions;839    }840  }841  function popInteractions(prevInteractions) {842    {843      __interactionsRef.current = prevInteractions;844    }845  }846  function markCommitTimeOfFallback() {847    globalMostRecentFallbackTime = now();848  }849  function markSkippedUpdateLanes(lane) {850    workInProgressRootSkippedLanes = mergeLanes(lane, workInProgressRootSkippedLanes);851  }852  function renderDidSuspend() {853    if (workInProgressRootExitStatus === RootIncomplete) {854      workInProgressRootExitStatus = RootSuspended;855    }856  }857  function renderDidSuspendDelayIfPossible() {858    if (workInProgressRootExitStatus === RootIncomplete || workInProgressRootExitStatus === RootSuspended) {859      workInProgressRootExitStatus = RootSuspendedWithDelay;860    } // Check if there are updates that we skipped tree that might have unblocked861    // this render.862    if (workInProgressRoot !== null && (includesNonIdleWork(workInProgressRootSkippedLanes) || includesNonIdleWork(workInProgressRootUpdatedLanes))) {863      // Mark the current render as suspended so that we switch to working on864      // the updates that were skipped. Usually we only suspend at the end of865      // the render phase.866      // TODO: We should probably always mark the root as suspended immediately867      // (inside this function), since by suspending at the end of the render868      // phase introduces a potential mistake where we suspend lanes that were869      // pinged or updated while we were rendering.870      markRootSuspended$1(workInProgressRoot, workInProgressRootRenderLanes);871    }872  }873  function renderDidError() {874    if (workInProgressRootExitStatus !== RootCompleted) {875      workInProgressRootExitStatus = RootErrored;876    }877  } // Called during render to determine if anything has suspended.878  // Returns false if we're not sure.879  function renderHasNotSuspendedYet() {880    // If something errored or completed, we can't really be sure,881    // so those are false.882    return workInProgressRootExitStatus === RootIncomplete;883  }884  function renderRootSync(root, lanes) {885    var prevExecutionContext = executionContext;886    executionContext |= RenderContext;887    var prevDispatcher = pushDispatcher(); // If the root or lanes have changed, throw out the existing stack888    // and prepare a fresh one. Otherwise we'll continue where we left off.889    if (workInProgressRoot !== root || workInProgressRootRenderLanes !== lanes) {890      prepareFreshStack(root, lanes);891      startWorkOnPendingInteractions(root, lanes);892    }893    var prevInteractions = pushInteractions(root);894    {895      markRenderStarted(lanes);896    }897    do {898      try {899        workLoopSync();900        break;901      } catch (thrownValue) {902        handleError(root, thrownValue);903      }904    } while (true);905    resetContextDependencies();906    {907      popInteractions(prevInteractions);908    }909    executionContext = prevExecutionContext;910    popDispatcher(prevDispatcher);911    if (workInProgress !== null) {912      // This is a sync render, so we should have finished the whole tree.913      {914        {915          throw Error( "Cannot commit an incomplete root. This error is likely caused by a bug in React. Please file an issue." );916        }917      }918    }919    {920      markRenderStopped();921    } // Set this to null to indicate there's no in-progress render.922    workInProgressRoot = null;923    workInProgressRootRenderLanes = NoLanes;924    return workInProgressRootExitStatus;925  } // The work loop is an extremely hot path. Tell Closure not to inline it.926  /** @noinline */927  function workLoopSync() {928    // Already timed out, so perform work without checking if we need to yield.929    while (workInProgress !== null) {930      performUnitOfWork(workInProgress);931    }932  }933  function renderRootConcurrent(root, lanes) {934    var prevExecutionContext = executionContext;935    executionContext |= RenderContext;936    var prevDispatcher = pushDispatcher(); // If the root or lanes have changed, throw out the existing stack937    // and prepare a fresh one. Otherwise we'll continue where we left off.938    if (workInProgressRoot !== root || workInProgressRootRenderLanes !== lanes) {939      resetRenderTimer();940      prepareFreshStack(root, lanes);941      startWorkOnPendingInteractions(root, lanes);942    }943    var prevInteractions = pushInteractions(root);944    {945      markRenderStarted(lanes);946    }947    do {948      try {949        workLoopConcurrent();950        break;951      } catch (thrownValue) {952        handleError(root, thrownValue);953      }954    } while (true);955    resetContextDependencies();956    {957      popInteractions(prevInteractions);958    }959    popDispatcher(prevDispatcher);960    executionContext = prevExecutionContext;961    if (workInProgress !== null) {962      // Still work remaining.963      {964        markRenderYielded();965      }966      return RootIncomplete;967    } else {968      // Completed the tree.969      {970        markRenderStopped();971      } // Set this to null to indicate there's no in-progress render.972      workInProgressRoot = null;973      workInProgressRootRenderLanes = NoLanes; // Return the final exit status.974      return workInProgressRootExitStatus;975    }976  }977  /** @noinline */978  function workLoopConcurrent() {979    // Perform work until Scheduler asks us to yield980    while (workInProgress !== null && !shouldYield()) {981      performUnitOfWork(workInProgress);982    }983  }984  function performUnitOfWork(unitOfWork) {985    // The current, flushed, state of this fiber is the alternate. Ideally986    // nothing should rely on this, but relying on it here means that we don't987    // need an additional field on the work in progress.988    var current = unitOfWork.alternate;989    setCurrentFiber(unitOfWork);990    var next;991    if ( (unitOfWork.mode & ProfileMode) !== NoMode) {992      startProfilerTimer(unitOfWork);993      next = beginWork$1(current, unitOfWork, subtreeRenderLanes);994      stopProfilerTimerIfRunningAndRecordDelta(unitOfWork, true);995    } else {996      next = beginWork$1(current, unitOfWork, subtreeRenderLanes);997    }998    resetCurrentFiber();999    unitOfWork.memoizedProps = unitOfWork.pendingProps;1000    if (next === null) {1001      // If this doesn't spawn new work, complete the current work.1002      completeUnitOfWork(unitOfWork);1003    } else {1004      workInProgress = next;1005    }1006    ReactCurrentOwner$2.current = null;1007  }1008  function completeUnitOfWork(unitOfWork) {1009    // Attempt to complete the current unit of work, then move to the next1010    // sibling. If there are no more siblings, return to the parent fiber.1011    var completedWork = unitOfWork;1012    do {1013      // The current, flushed, state of this fiber is the alternate. Ideally1014      // nothing should rely on this, but relying on it here means that we don't1015      // need an additional field on the work in progress.1016      var current = completedWork.alternate;1017      var returnFiber = completedWork.return; // Check if the work completed or if something threw.1018      if ((completedWork.flags & Incomplete) === NoFlags) {1019        setCurrentFiber(completedWork);1020        var next = void 0;1021        if ( (completedWork.mode & ProfileMode) === NoMode) {1022          next = completeWork(current, completedWork, subtreeRenderLanes);1023        } else {1024          startProfilerTimer(completedWork);1025          next = completeWork(current, completedWork, subtreeRenderLanes); // Update render duration assuming we didn't error.1026          stopProfilerTimerIfRunningAndRecordDelta(completedWork, false);1027        }1028        resetCurrentFiber();1029        if (next !== null) {1030          // Completing this fiber spawned new work. Work on that next.1031          workInProgress = next;1032          return;1033        }1034        resetChildLanes(completedWork);1035        if (returnFiber !== null && // Do not append effects to parents if a sibling failed to complete1036        (returnFiber.flags & Incomplete) === NoFlags) {1037          // Append all the effects of the subtree and this fiber onto the effect1038          // list of the parent. The completion order of the children affects the1039          // side-effect order.1040          if (returnFiber.firstEffect === null) {1041            returnFiber.firstEffect = completedWork.firstEffect;1042          }1043          if (completedWork.lastEffect !== null) {1044            if (returnFiber.lastEffect !== null) {1045              returnFiber.lastEffect.nextEffect = completedWork.firstEffect;1046            }1047            returnFiber.lastEffect = completedWork.lastEffect;1048          } // If this fiber had side-effects, we append it AFTER the children's1049          // side-effects. We can perform certain side-effects earlier if needed,1050          // by doing multiple passes over the effect list. We don't want to1051          // schedule our own side-effect on our own list because if end up1052          // reusing children we'll schedule this effect onto itself since we're1053          // at the end.1054          var flags = completedWork.flags; // Skip both NoWork and PerformedWork tags when creating the effect1055          // list. PerformedWork effect is read by React DevTools but shouldn't be1056          // committed.1057          if (flags > PerformedWork) {1058            if (returnFiber.lastEffect !== null) {1059              returnFiber.lastEffect.nextEffect = completedWork;1060            } else {1061              returnFiber.firstEffect = completedWork;1062            }1063            returnFiber.lastEffect = completedWork;1064          }1065        }1066      } else {1067        // This fiber did not complete because something threw. Pop values off1068        // the stack without entering the complete phase. If this is a boundary,1069        // capture values if possible.1070        var _next = unwindWork(completedWork); // Because this fiber did not complete, don't reset its expiration time.1071        if (_next !== null) {1072          // If completing this work spawned new work, do that next. We'll come1073          // back here again.1074          // Since we're restarting, remove anything that is not a host effect1075          // from the effect tag.1076          _next.flags &= HostEffectMask;1077          workInProgress = _next;1078          return;1079        }1080        if ( (completedWork.mode & ProfileMode) !== NoMode) {1081          // Record the render duration for the fiber that errored.1082          stopProfilerTimerIfRunningAndRecordDelta(completedWork, false); // Include the time spent working on failed children before continuing.1083          var actualDuration = completedWork.actualDuration;1084          var child = completedWork.child;1085          while (child !== null) {1086            actualDuration += child.actualDuration;1087            child = child.sibling;1088          }1089          completedWork.actualDuration = actualDuration;1090        }1091        if (returnFiber !== null) {1092          // Mark the parent fiber as incomplete and clear its effect list.1093          returnFiber.firstEffect = returnFiber.lastEffect = null;1094          returnFiber.flags |= Incomplete;1095        }1096      }1097      var siblingFiber = completedWork.sibling;1098      if (siblingFiber !== null) {1099        // If there is more work to do in this returnFiber, do that next.1100        workInProgress = siblingFiber;1101        return;1102      } // Otherwise, return to the parent1103      completedWork = returnFiber; // Update the next thing we're working on in case something throws.1104      workInProgress = completedWork;1105    } while (completedWork !== null); // We've reached the root.1106    if (workInProgressRootExitStatus === RootIncomplete) {1107      workInProgressRootExitStatus = RootCompleted;1108    }1109  }1110  function resetChildLanes(completedWork) {1111    if ( // TODO: Move this check out of the hot path by moving `resetChildLanes`1112    // to switch statement in `completeWork`.1113    (completedWork.tag === LegacyHiddenComponent || completedWork.tag === OffscreenComponent) && completedWork.memoizedState !== null && !includesSomeLane(subtreeRenderLanes, OffscreenLane) && (completedWork.mode & ConcurrentMode) !== NoLanes) {1114      // The children of this component are hidden. Don't bubble their1115      // expiration times.1116      return;1117    }1118    var newChildLanes = NoLanes; // Bubble up the earliest expiration time.1119    if ( (completedWork.mode & ProfileMode) !== NoMode) {1120      // In profiling mode, resetChildExpirationTime is also used to reset1121      // profiler durations.1122      var actualDuration = completedWork.actualDuration;1123      var treeBaseDuration = completedWork.selfBaseDuration; // When a fiber is cloned, its actualDuration is reset to 0. This value will1124      // only be updated if work is done on the fiber (i.e. it doesn't bailout).1125      // When work is done, it should bubble to the parent's actualDuration. If1126      // the fiber has not been cloned though, (meaning no work was done), then1127      // this value will reflect the amount of time spent working on a previous1128      // render. In that case it should not bubble. We determine whether it was1129      // cloned by comparing the child pointer.1130      var shouldBubbleActualDurations = completedWork.alternate === null || completedWork.child !== completedWork.alternate.child;1131      var child = completedWork.child;1132      while (child !== null) {1133        newChildLanes = mergeLanes(newChildLanes, mergeLanes(child.lanes, child.childLanes));1134        if (shouldBubbleActualDurations) {1135          actualDuration += child.actualDuration;1136        }1137        treeBaseDuration += child.treeBaseDuration;1138        child = child.sibling;1139      }1140      var isTimedOutSuspense = completedWork.tag === SuspenseComponent && completedWork.memoizedState !== null;1141      if (isTimedOutSuspense) {1142        // Don't count time spent in a timed out Suspense subtree as part of the base duration.1143        var primaryChildFragment = completedWork.child;1144        if (primaryChildFragment !== null) {1145          treeBaseDuration -= primaryChildFragment.treeBaseDuration;1146        }1147      }1148      completedWork.actualDuration = actualDuration;1149      completedWork.treeBaseDuration = treeBaseDuration;1150    } else {1151      var _child = completedWork.child;1152      while (_child !== null) {1153        newChildLanes = mergeLanes(newChildLanes, mergeLanes(_child.lanes, _child.childLanes));1154        _child = _child.sibling;1155      }1156    }1157    completedWork.childLanes = newChildLanes;1158  }1159  function commitRoot(root) {1160    var renderPriorityLevel = getCurrentPriorityLevel();1161    runWithPriority$1(ImmediatePriority$1, commitRootImpl.bind(null, root, renderPriorityLevel));1162    return null;1163  }1164  function commitRootImpl(root, renderPriorityLevel) {1165    do {1166      // `flushPassiveEffects` will call `flushSyncUpdateQueue` at the end, which1167      // means `flushPassiveEffects` will sometimes result in additional1168      // passive effects. So we need to keep flushing in a loop until there are1169      // no more pending effects.1170      // TODO: Might be better if `flushPassiveEffects` did not automatically1171      // flush synchronous work at the end, to avoid factoring hazards like this.1172      flushPassiveEffects();1173    } while (rootWithPendingPassiveEffects !== null);1174    flushRenderPhaseStrictModeWarningsInDEV();1175    if (!((executionContext & (RenderContext | CommitContext)) === NoContext)) {1176      {1177        throw Error( "Should not already be working." );1178      }1179    }1180    var finishedWork = root.finishedWork;1181    var lanes = root.finishedLanes;1182    {1183      markCommitStarted(lanes);1184    }1185    if (finishedWork === null) {1186      {1187        markCommitStopped();1188      }1189      return null;1190    }1191    root.finishedWork = null;1192    root.finishedLanes = NoLanes;1193    if (!(finishedWork !== root.current)) {1194      {1195        throw Error( "Cannot commit the same tree as before. This error is likely caused by a bug in React. Please file an issue." );1196      }1197    } // commitRoot never returns a continuation; it always finishes synchronously.1198    // So we can clear these now to allow a new callback to be scheduled.1199    root.callbackNode = null; // Update the first and last pending times on this root. The new first1200    // pending time is whatever is left on the root fiber.1201    var remainingLanes = mergeLanes(finishedWork.lanes, finishedWork.childLanes);1202    markRootFinished(root, remainingLanes); // Clear already finished discrete updates in case that a later call of1203    // `flushDiscreteUpdates` starts a useless render pass which may cancels1204    // a scheduled timeout.1205    if (rootsWithPendingDiscreteUpdates !== null) {1206      if (!hasDiscreteLanes(remainingLanes) && rootsWithPendingDiscreteUpdates.has(root)) {1207        rootsWithPendingDiscreteUpdates.delete(root);1208      }1209    }1210    if (root === workInProgressRoot) {1211      // We can reset these now that they are finished.1212      workInProgressRoot = null;1213      workInProgress = null;1214      workInProgressRootRenderLanes = NoLanes;1215    } // Get the list of effects.1216    var firstEffect;1217    if (finishedWork.flags > PerformedWork) {1218      // A fiber's effect list consists only of its children, not itself. So if1219      // the root has an effect, we need to add it to the end of the list. The1220      // resulting list is the set that would belong to the root's parent, if it1221      // had one; that is, all the effects in the tree including the root.1222      if (finishedWork.lastEffect !== null) {1223        finishedWork.lastEffect.nextEffect = finishedWork;1224        firstEffect = finishedWork.firstEffect;1225      } else {1226        firstEffect = finishedWork;1227      }1228    } else {1229      // There is no effect on the root.1230      firstEffect = finishedWork.firstEffect;1231    }1232    if (firstEffect !== null) {1233      var prevExecutionContext = executionContext;1234      executionContext |= CommitContext;1235      var prevInteractions = pushInteractions(root); // Reset this to null before calling lifecycles1236      ReactCurrentOwner$2.current = null; // The commit phase is broken into several sub-phases. We do a separate pass1237      // of the effect list for each phase: all mutation effects come before all1238      // layout effects, and so on.1239      // The first phase a "before mutation" phase. We use this phase to read the1240      // state of the host tree right before we mutate it. This is where1241      // getSnapshotBeforeUpdate is called.1242      focusedInstanceHandle = prepareForCommit(root.containerInfo);1243      shouldFireAfterActiveInstanceBlur = false;1244      nextEffect = firstEffect;1245      do {1246        {1247          invokeGuardedCallback(null, commitBeforeMutationEffects, null);1248          if (hasCaughtError()) {1249            if (!(nextEffect !== null)) {1250              {1251                throw Error( "Should be working on an effect." );1252              }1253            }1254            var error = clearCaughtError();1255            captureCommitPhaseError(nextEffect, error);1256            nextEffect = nextEffect.nextEffect;1257          }1258        }1259      } while (nextEffect !== null); // We no longer need to track the active instance fiber1260      focusedInstanceHandle = null;1261      {1262        // Mark the current commit time to be shared by all Profilers in this1263        // batch. This enables them to be grouped later.1264        recordCommitTime();1265      } // The next phase is the mutation phase, where we mutate the host tree.1266      nextEffect = firstEffect;1267      do {1268        {1269          invokeGuardedCallback(null, commitMutationEffects, null, root, renderPriorityLevel);1270          if (hasCaughtError()) {1271            if (!(nextEffect !== null)) {1272              {1273                throw Error( "Should be working on an effect." );1274              }1275            }1276            var _error = clearCaughtError();1277            captureCommitPhaseError(nextEffect, _error);1278            nextEffect = nextEffect.nextEffect;1279          }1280        }1281      } while (nextEffect !== null);1282      resetAfterCommit(root.containerInfo); // The work-in-progress tree is now the current tree. This must come after1283      // the mutation phase, so that the previous tree is still current during1284      // componentWillUnmount, but before the layout phase, so that the finished1285      // work is current during componentDidMount/Update.1286      root.current = finishedWork; // The next phase is the layout phase, where we call effects that read1287      // the host tree after it's been mutated. The idiomatic use case for this is1288      // layout, but class component lifecycles also fire here for legacy reasons.1289      nextEffect = firstEffect;1290      do {1291        {1292          invokeGuardedCallback(null, commitLayoutEffects, null, root, lanes);1293          if (hasCaughtError()) {1294            if (!(nextEffect !== null)) {1295              {1296                throw Error( "Should be working on an effect." );1297              }1298            }1299            var _error2 = clearCaughtError();1300            captureCommitPhaseError(nextEffect, _error2);1301            nextEffect = nextEffect.nextEffect;1302          }1303        }1304      } while (nextEffect !== null);1305      nextEffect = null; // Tell Scheduler to yield at the end of the frame, so the browser has an1306      // opportunity to paint.1307      requestPaint();1308      {1309        popInteractions(prevInteractions);1310      }1311      executionContext = prevExecutionContext;1312    } else {1313      // No effects.1314      root.current = finishedWork; // Measure these anyway so the flamegraph explicitly shows that there were1315      // no effects.1316      // TODO: Maybe there's a better way to report this.1317      {1318        recordCommitTime();1319      }1320    }1321    var rootDidHavePassiveEffects = rootDoesHavePassiveEffects;1322    if (rootDoesHavePassiveEffects) {1323      // This commit has passive effects. Stash a reference to them. But don't1324      // schedule a callback until after flushing layout work.1325      rootDoesHavePassiveEffects = false;1326      rootWithPendingPassiveEffects = root;1327      pendingPassiveEffectsLanes = lanes;1328      pendingPassiveEffectsRenderPriority = renderPriorityLevel;1329    } else {1330      // We are done with the effect chain at this point so let's clear the1331      // nextEffect pointers to assist with GC. If we have passive effects, we'll1332      // clear this in flushPassiveEffects.1333      nextEffect = firstEffect;1334      while (nextEffect !== null) {1335        var nextNextEffect = nextEffect.nextEffect;1336        nextEffect.nextEffect = null;1337        if (nextEffect.flags & Deletion) {1338          detachFiberAfterEffects(nextEffect);1339        }1340        nextEffect = nextNextEffect;1341      }1342    } // Read this again, since an effect might have updated it1343    remainingLanes = root.pendingLanes; // Check if there's remaining work on this root1344    if (remainingLanes !== NoLanes) {1345      {1346        if (spawnedWorkDuringRender !== null) {1347          var expirationTimes = spawnedWorkDuringRender;1348          spawnedWorkDuringRender = null;1349          for (var i = 0; i < expirationTimes.length; i++) {1350            scheduleInteractions(root, expirationTimes[i], root.memoizedInteractions);1351          }1352        }1353        schedulePendingInteractions(root, remainingLanes);1354      }1355    } else {1356      // If there's no remaining work, we can clear the set of already failed1357      // error boundaries.1358      legacyErrorBoundariesThatAlreadyFailed = null;1359    }1360    {1361      if (!rootDidHavePassiveEffects) {1362        // If there are no passive effects, then we can complete the pending interactions.1363        // Otherwise, we'll wait until after the passive effects are flushed.1364        // Wait to do this until after remaining work has been scheduled,1365        // so that we don't prematurely signal complete for interactions when there's e.g. hidden work.1366        finishPendingInteractions(root, lanes);1367      }1368    }1369    if (remainingLanes === SyncLane) {1370      // Count the number of times the root synchronously re-renders without1371      // finishing. If there are too many, it indicates an infinite update loop.1372      if (root === rootWithNestedUpdates) {1373        nestedUpdateCount++;1374      } else {1375        nestedUpdateCount = 0;1376        rootWithNestedUpdates = root;1377      }1378    } else {1379      nestedUpdateCount = 0;1380    }1381    onCommitRoot(finishedWork.stateNode, renderPriorityLevel);1382    {1383      onCommitRoot$1();1384    } // Always call this before exiting `commitRoot`, to ensure that any1385    // additional work on this root is scheduled.1386    ensureRootIsScheduled(root, now());1387    if (hasUncaughtError) {1388      hasUncaughtError = false;1389      var _error3 = firstUncaughtError;1390      firstUncaughtError = null;1391      throw _error3;1392    }1393    if ((executionContext & LegacyUnbatchedContext) !== NoContext) {1394      {1395        markCommitStopped();1396      } // This is a legacy edge case. We just committed the initial mount of1397      // a ReactDOM.render-ed root inside of batchedUpdates. The commit fired1398      // synchronously, but layout updates should be deferred until the end1399      // of the batch.1400      return null;1401    } // If layout work was scheduled, flush it now.1402    flushSyncCallbackQueue();1403    {1404      markCommitStopped();1405    }1406    return null;1407  }1408  function commitBeforeMutationEffects() {1409    while (nextEffect !== null) {1410      var current = nextEffect.alternate;1411      if (!shouldFireAfterActiveInstanceBlur && focusedInstanceHandle !== null) {1412        if ((nextEffect.flags & Deletion) !== NoFlags) {1413          if (doesFiberContain(nextEffect, focusedInstanceHandle)) {1414            shouldFireAfterActiveInstanceBlur = true;1415          }1416        } else {1417          // TODO: Move this out of the hot path using a dedicated effect tag.1418          if (nextEffect.tag === SuspenseComponent && isSuspenseBoundaryBeingHidden(current, nextEffect) && doesFiberContain(nextEffect, focusedInstanceHandle)) {1419            shouldFireAfterActiveInstanceBlur = true;1420          }1421        }1422      }1423      var flags = nextEffect.flags;1424      if ((flags & Snapshot) !== NoFlags) {1425        setCurrentFiber(nextEffect);1426        commitBeforeMutationLifeCycles(current, nextEffect);1427        resetCurrentFiber();1428      }1429      if ((flags & Passive) !== NoFlags) {1430        // If there are passive effects, schedule a callback to flush at1431        // the earliest opportunity.1432        if (!rootDoesHavePassiveEffects) {1433          rootDoesHavePassiveEffects = true;1434          scheduleCallback(NormalPriority$1, function () {1435            flushPassiveEffects();1436            return null;1437          });1438        }1439      }1440      nextEffect = nextEffect.nextEffect;1441    }1442  }1443  function commitMutationEffects(root, renderPriorityLevel) {1444    // TODO: Should probably move the bulk of this function to commitWork.1445    while (nextEffect !== null) {1446      setCurrentFiber(nextEffect);1447      var flags = nextEffect.flags;1448      if (flags & ContentReset) {1449        commitResetTextContent(nextEffect);1450      }1451      if (flags & Ref) {1452        var current = nextEffect.alternate;1453        if (current !== null) {1454          commitDetachRef(current);1455        }1456      } // The following switch statement is only concerned about placement,1457      // updates, and deletions. To avoid needing to add a case for every possible1458      // bitmap value, we remove the secondary effects from the effect tag and1459      // switch on that value.1460      var primaryFlags = flags & (Placement | Update | Deletion | Hydrating);1461      switch (primaryFlags) {1462        case Placement:1463          {1464            commitPlacement(nextEffect); // Clear the "placement" from effect tag so that we know that this is1465            // inserted, before any life-cycles like componentDidMount gets called.1466            // TODO: findDOMNode doesn't rely on this any more but isMounted does1467            // and isMounted is deprecated anyway so we should be able to kill this.1468            nextEffect.flags &= ~Placement;1469            break;1470          }1471        case PlacementAndUpdate:1472          {1473            // Placement1474            commitPlacement(nextEffect); // Clear the "placement" from effect tag so that we know that this is1475            // inserted, before any life-cycles like componentDidMount gets called.1476            nextEffect.flags &= ~Placement; // Update1477            var _current = nextEffect.alternate;1478            commitWork(_current, nextEffect);1479            break;1480          }1481        case Hydrating:1482          {1483            nextEffect.flags &= ~Hydrating;1484            break;1485          }1486        case HydratingAndUpdate:1487          {1488            nextEffect.flags &= ~Hydrating; // Update1489            var _current2 = nextEffect.alternate;1490            commitWork(_current2, nextEffect);1491            break;1492          }1493        case Update:1494          {1495            var _current3 = nextEffect.alternate;1496            commitWork(_current3, nextEffect);1497            break;1498          }1499        case Deletion:1500          {1501            commitDeletion(root, nextEffect);1502            break;1503          }1504      }1505      resetCurrentFiber();1506      nextEffect = nextEffect.nextEffect;1507    }1508  }1509  function commitLayoutEffects(root, committedLanes) {1510    {1511      markLayoutEffectsStarted(committedLanes);1512    } // TODO: Should probably move the bulk of this function to commitWork.1513    while (nextEffect !== null) {1514      setCurrentFiber(nextEffect);1515      var flags = nextEffect.flags;1516      if (flags & (Update | Callback)) {1517        var current = nextEffect.alternate;1518        commitLifeCycles(root, current, nextEffect);1519      }1520      {1521        if (flags & Ref) {1522          commitAttachRef(nextEffect);1523        }1524      }1525      resetCurrentFiber();1526      nextEffect = nextEffect.nextEffect;1527    }1528    {1529      markLayoutEffectsStopped();1530    }1531  }1532  function flushPassiveEffects() {1533    // Returns whether passive effects were flushed.1534    if (pendingPassiveEffectsRenderPriority !== NoPriority$1) {1535      var priorityLevel = pendingPassiveEffectsRenderPriority > NormalPriority$1 ? NormalPriority$1 : pendingPassiveEffectsRenderPriority;1536      pendingPassiveEffectsRenderPriority = NoPriority$1;1537      {1538        return runWithPriority$1(priorityLevel, flushPassiveEffectsImpl);1539      }1540    }1541    return false;1542  }1543  function enqueuePendingPassiveHookEffectMount(fiber, effect) {1544    pendingPassiveHookEffectsMount.push(effect, fiber);1545    if (!rootDoesHavePassiveEffects) {1546      rootDoesHavePassiveEffects = true;1547      scheduleCallback(NormalPriority$1, function () {1548        flushPassiveEffects();1549        return null;1550      });1551    }1552  }1553  function enqueuePendingPassiveHookEffectUnmount(fiber, effect) {1554    pendingPassiveHookEffectsUnmount.push(effect, fiber);1555    {1556      fiber.flags |= PassiveUnmountPendingDev;1557      var alternate = fiber.alternate;1558      if (alternate !== null) {1559        alternate.flags |= PassiveUnmountPendingDev;1560      }1561    }1562    if (!rootDoesHavePassiveEffects) {1563      rootDoesHavePassiveEffects = true;1564      scheduleCallback(NormalPriority$1, function () {1565        flushPassiveEffects();1566        return null;1567      });1568    }1569  }1570  function invokePassiveEffectCreate(effect) {1571    var create = effect.create;1572    effect.destroy = create();1573  }1574  function flushPassiveEffectsImpl() {1575    if (rootWithPendingPassiveEffects === null) {1576      return false;1577    }1578    var root = rootWithPendingPassiveEffects;1579    var lanes = pendingPassiveEffectsLanes;1580    rootWithPendingPassiveEffects = null;1581    pendingPassiveEffectsLanes = NoLanes;1582    if (!((executionContext & (RenderContext | CommitContext)) === NoContext)) {1583      {1584        throw Error( "Cannot flush passive effects while already rendering." );1585      }1586    }1587    {1588      markPassiveEffectsStarted(lanes);1589    }1590    {1591      isFlushingPassiveEffects = true;1592    }1593    var prevExecutionContext = executionContext;1594    executionContext |= CommitContext;1595    var prevInteractions = pushInteractions(root); // It's important that ALL pending passive effect destroy functions are called1596    // before ANY passive effect create functions are called.1597    // Otherwise effects in sibling components might interfere with each other.1598    // e.g. a destroy function in one component may unintentionally override a ref1599    // value set by a create function in another component.1600    // Layout effects have the same constraint.1601    // First pass: Destroy stale passive effects.1602    var unmountEffects = pendingPassiveHookEffectsUnmount;1603    pendingPassiveHookEffectsUnmount = [];1604    for (var i = 0; i < unmountEffects.length; i += 2) {1605      var _effect = unmountEffects[i];1606      var fiber = unmountEffects[i + 1];1607      var destroy = _effect.destroy;1608      _effect.destroy = undefined;1609      {...ReactFiberWorkLoop.js
Source:ReactFiberWorkLoop.js  
...425  rootWithPendingPassiveEffects = null;426  pendingPassiveEffectsLanes = NoLanes;427  const prevExecutionContext = executionContext;428  executionContext |= CommitContext;429  const prevInteractions = pushInteractions(root);430  commitPassiveUnmountEffects(root.current);431  commitPassiveMountEffects(root, root.current);432  executionContext = prevExecutionContext;433  flushSyncCallbackQueue();434  // If additional passive effects were scheduled, increment a counter. If this435  // exceeds the limit, we'll fire a warning.436  nestedPassiveUpdateCount =437    rootWithPendingPassiveEffects === null ? 0 : nestedPassiveUpdateCount + 1;438  return true;439}440function pushInteractions(root) {441  // if (enableSchedulerTracing) {442  //     const prevInteractions = __interactionsRef.current;443  //     __interactionsRef.current = root.memoizedInteractions;444  //     return prevInteractions;445  // }446  return null;447}448// This is split into a separate function so we can mark a fiber with pending449// work without treating it as a typical update that originates from an event;450// e.g. retrying a Suspense boundary isn't an update, but it does schedule work451// on a fiber.452function markUpdateLaneFromFiberToRoot(sourceFiber, lane) {453  // Update the source fiber's lanes454  sourceFiber.lanes = mergeLanes(sourceFiber.lanes, lane);455  let alternate = sourceFiber.alternate;456  if (alternate !== null) {457    alternate.lanes = mergeLanes(alternate.lanes, lane);458  }459  // Walk the parent path to the root and update the child expiration time.460  let node = sourceFiber;461  let parent = sourceFiber.return;462  while (parent !== null) {463    parent.childLanes = mergeLanes(parent.childLanes, lane);464    alternate = parent.alternate;465    if (alternate !== null) {466      alternate.childLanes = mergeLanes(alternate.childLanes, lane);467    }468    node = parent;469    parent = parent.return;470  }471  if (node.tag === HostRoot) {472    const root = node.stateNode;473    return root;474  } else {475    return null;476  }477}478function pushDispatcher() {479  // const prevDispatcher = ReactCurrentDispatcher.current;480}481function popDispatcher(prevDispatcher) {}482function renderRootSync(root, lanes) {483  const prevExecutionContext = executionContext;484  executionContext |= RenderContext;485  // const prevDispatcher = pushDispatcher();486  // If the root or lanes have changed, throw out the existing stack487  // and prepare a fresh one. Otherwise we'll continue where we left off.488  if (workInProgressRoot !== root || workInProgressRootRenderLanes !== lanes) {489    prepareFreshStack(root, lanes);490    // startWorkOnPendingInteractions(root, lanes);491  }492  // const prevInteractions = pushInteractions(root);493  do {494    try {495      workLoopSync();496      break;497    } catch (thrownValue) {498      handleError(root, thrownValue);499    }500  } while (true);501  // resetContextDependencies();502  executionContext = prevExecutionContext;503  // popDispatcher(prevDispatcher);504  if (workInProgress !== null) {505    // This is a sync render, so we should have finished the whole tree.506    console.error(...4 - commitWork.js
Source:4 - commitWork.js  
...100    const previousPriority = getCurrentUpdatePriority();101    setCurrentUpdatePriority(DiscreteEventPriority);102    const prevExecutionContext = executionContext;103    executionContext |= CommitContext;104    const prevInteractions = pushInteractions(root);105    // Reset this to null before calling lifecycles106    ReactCurrentOwner.current = null;107    // The commit phase is broken into several sub-phases. We do a separate pass108    // of the effect list for each phase: all mutation effects come before all109    // layout effects, and so on.110    // The first phase a "before mutation" phase. We use this phase to read the111    // state of the host tree right before we mutate it. This is where112    // getSnapshotBeforeUpdate is called.113    const shouldFireAfterActiveInstanceBlur = commitBeforeMutationEffects(114      root,115      finishedWork,116    );117    if (enableProfilerTimer) {118      // Mark the current commit time to be shared by all Profilers in this119      // batch. This enables them to be grouped later.120      recordCommitTime();121    }122    if (enableProfilerTimer && enableProfilerNestedUpdateScheduledHook) {123      // Track the root here, rather than in commitLayoutEffects(), because of ref setters.124      // Updates scheduled during ref detachment should also be flagged.125      rootCommittingMutationOrLayoutEffects = root;126    }127    // The next phase is the mutation phase, where we mutate the host tree.128    commitMutationEffects(root, finishedWork);129    if (shouldFireAfterActiveInstanceBlur) {130      afterActiveInstanceBlur();131    }132    resetAfterCommit(root.containerInfo);133    // The work-in-progress tree is now the current tree. This must come after134    // the mutation phase, so that the previous tree is still current during135    // componentWillUnmount, but before the layout phase, so that the finished136    // work is current during componentDidMount/Update.137    root.current = finishedWork;138    // The next phase is the layout phase, where we call effects that read139    // the host tree after it's been mutated. The idiomatic use case for this is140    // layout, but class component lifecycles also fire here for legacy reasons.141    if (enableSchedulingProfiler) {142      markLayoutEffectsStarted(lanes);143    }144    commitLayoutEffects(finishedWork, root, lanes);145    if (enableSchedulingProfiler) {146      markLayoutEffectsStopped();147    }148    if (enableProfilerTimer && enableProfilerNestedUpdateScheduledHook) {149      rootCommittingMutationOrLayoutEffects = null;150    }151    // Tell Scheduler to yield at the end of the frame, so the browser has an152    // opportunity to paint.153    requestPaint();154    if (enableSchedulerTracing) {155      popInteractions(((prevInteractions: any): Set<Interaction>));156    }157    executionContext = prevExecutionContext;158    // Reset the priority to the previous non-sync value.159    setCurrentUpdatePriority(previousPriority);160    ReactCurrentBatchConfig.transition = prevTransition;161  } else {162    // No effects.163    root.current = finishedWork;164    // Measure these anyway so the flamegraph explicitly shows that there were165    // no effects.166    // TODO: Maybe there's a better way to report this.167    if (enableProfilerTimer) {168      recordCommitTime();169    }170  }171  const rootDidHavePassiveEffects = rootDoesHavePassiveEffects;172  if (rootDoesHavePassiveEffects) {173    // This commit has passive effects. Stash a reference to them. But don't174    // schedule a callback until after flushing layout work.175    rootDoesHavePassiveEffects = false;176    rootWithPendingPassiveEffects = root;177    pendingPassiveEffectsLanes = lanes;178  }179  // Read this again, since an effect might have updated it180  remainingLanes = root.pendingLanes;181  // Check if there's remaining work on this root182  if (remainingLanes !== NoLanes) {183    if (enableSchedulerTracing) {184      if (spawnedWorkDuringRender !== null) {185        const expirationTimes = spawnedWorkDuringRender;186        spawnedWorkDuringRender = null;187        for (let i = 0; i < expirationTimes.length; i++) {188          scheduleInteractions(189            root,190            expirationTimes[i],191            root.memoizedInteractions,192          );193        }194      }195      schedulePendingInteractions(root, remainingLanes);196    }197  } else {198    // If there's no remaining work, we can clear the set of already failed199    // error boundaries.200    legacyErrorBoundariesThatAlreadyFailed = null;201  }202  if (enableSchedulerTracing) {203    if (!rootDidHavePassiveEffects) {204      // If there are no passive effects, then we can complete the pending interactions.205      // Otherwise, we'll wait until after the passive effects are flushed.206      // Wait to do this until after remaining work has been scheduled,207      // so that we don't prematurely signal complete for interactions when there's e.g. hidden work.208      finishPendingInteractions(root, lanes);209    }210  }211  if (includesSomeLane(remainingLanes, (SyncLane: Lane))) {212    if (enableProfilerTimer && enableProfilerNestedUpdatePhase) {213      markNestedUpdateScheduled();214    }215    // Count the number of times the root synchronously re-renders without216    // finishing. If there are too many, it indicates an infinite update loop.217    if (root === rootWithNestedUpdates) {218      nestedUpdateCount++;219    } else {220      nestedUpdateCount = 0;221      rootWithNestedUpdates = root;222    }223  } else {224    nestedUpdateCount = 0;225  }226  onCommitRootDevTools(finishedWork.stateNode, renderPriorityLevel);227  // Always call this before exiting `commitRoot`, to ensure that any228  // additional work on this root is scheduled.229  ensureRootIsScheduled(root, now());230  if (hasUncaughtError) {231    hasUncaughtError = false;232    const error = firstUncaughtError;233    firstUncaughtError = null;234    throw error;235  }236  if ((executionContext & LegacyUnbatchedContext) !== NoContext) {237    if (enableSchedulingProfiler) {238      markCommitStopped();239    }240    // This is a legacy edge case. We just committed the initial mount of241    // a ReactDOM.render-ed root inside of batchedUpdates. The commit fired242    // synchronously, but layout updates should be deferred until the end243    // of the batch.244    return null;245  }246  // If the passive effects are the result of a discrete render, flush them247  // synchronously at the end of the current task so that the result is248  // immediately observable. Otherwise, we assume that they are not249  // order-dependent and do not need to be observed by external systems, so we250  // can wait until after paint.251  // TODO: We can optimize this by not scheduling the callback earlier. Since we252  // currently schedule the callback in multiple places, will wait until those253  // are consolidated.254  if (255    includesSomeLane(pendingPassiveEffectsLanes, SyncLane) &&256    root.tag !== LegacyRoot257  ) {258    flushPassiveEffects();259  }260  // If layout work was scheduled, flush it now.261  flushSyncCallbackQueue();262  if (enableSchedulingProfiler) {263    markCommitStopped();264  }265  return null;266}267export function flushPassiveEffects(): boolean {268  // Returns whether passive effects were flushed.269  if (pendingPassiveEffectsLanes !== NoLanes) {270    const priority = higherEventPriority(271      DefaultEventPriority,272      lanesToEventPriority(pendingPassiveEffectsLanes),273    );274    const prevTransition = ReactCurrentBatchConfig.transition;275    const previousPriority = getCurrentUpdatePriority();276    try {277      ReactCurrentBatchConfig.transition = 0;278      setCurrentUpdatePriority(priority);279      return flushPassiveEffectsImpl();280    } finally {281      setCurrentUpdatePriority(previousPriority);282      ReactCurrentBatchConfig.transition = prevTransition;283    }284  }285  return false;286}287function flushPassiveEffectsImpl() {288  if (rootWithPendingPassiveEffects === null) {289    return false;290  }291  const root = rootWithPendingPassiveEffects;292  const lanes = pendingPassiveEffectsLanes;293  rootWithPendingPassiveEffects = null;294  pendingPassiveEffectsLanes = NoLanes;295  invariant(296    (executionContext & (RenderContext | CommitContext)) === NoContext,297    'Cannot flush passive effects while already rendering.',298  );299  if (enableSchedulingProfiler) {300    markPassiveEffectsStarted(lanes);301  }302  const prevExecutionContext = executionContext;303  executionContext |= CommitContext;304  const prevInteractions = pushInteractions(root);305  commitPassiveUnmountEffects(root.current);306  commitPassiveMountEffects(root, root.current);307  // TODO: Move to commitPassiveMountEffects308  if (enableProfilerTimer && enableProfilerCommitHooks) {309    const profilerEffects = pendingPassiveProfilerEffects;310    pendingPassiveProfilerEffects = [];311    for (let i = 0; i < profilerEffects.length; i++) {312      const fiber = ((profilerEffects[i]: any): Fiber);313      commitPassiveEffectDurations(root, fiber);314    }315  }316  if (enableSchedulerTracing) {317    popInteractions(((prevInteractions: any): Set<Interaction>));318    finishPendingInteractions(root, lanes);...commitRootImpl.js
Source:commitRootImpl.js  
...58    }59    if (firstEffect !== null) {60        var prevExecutionContext = executionContext;61        executionContext |= CommitContext;62        var prevInteractions = pushInteractions(root); // Reset this to null before calling lifecycles63        ReactCurrentOwner$2.current = null; // The commit phase is broken into several sub-phases. We do a separate pass64        // of the effect list for each phase: all mutation effects come before all65        // layout effects, and so on.66        // The first phase a "before mutation" phase. We use this phase to read the67        // state of the host tree right before we mutate it. This is where68        // getSnapshotBeforeUpdate is called.69        startCommitSnapshotEffectsTimer();70        prepareForCommit(root.containerInfo);71        nextEffect = firstEffect;72        do {73            {74                invokeGuardedCallback(null, commitBeforeMutationEffects, null);75                if (hasCaughtError()) {76                    (function () {...finishSyncRender.js
Source:finishSyncRender.js  
...41    }42    if (firstEffect !== null) {43        const prevExecutionContext = executionContext;44        executionContext |= CommitContext;45        const prevInteractions = pushInteractions(root);46        ReactCurrentOwner.current = null;47        startCommitSnapshotEffectsTimer();48        prepareForCommit(root.containerInfo);49        nextEffect = firstEffect;50        do {51            try {52                commitBeforeMutationEffects();53            } catch (error) {54                invariant(nextEffect !== null, 'Should be working on an effect.');55                captureCommitPhaseError(nextEffect, error);56                nextEffect = nextEffect.nextEffect;57            }58        } while (nextEffect !== null);59        stopCommitSnapshotEffectsTimer();...flushPassiveEffectsImpl.js
Source:flushPassiveEffectsImpl.js  
...14        }15    })();16    var prevExecutionContext = executionContext;17    executionContext |= CommitContext;18    var prevInteractions = pushInteractions(root); // Note: This currently assumes there are no passive effects on the root19    // fiber, because the root is not part of its own effect list. This could20    // change in the future.21    var effect = root.current.firstEffect;22    while (effect !== null) {23        {24            setCurrentFiber(effect);25            invokeGuardedCallback(null, commitPassiveHookEffects, null, effect);26            if (hasCaughtError()) {27                (function () {28                    if (!(effect !== null)) {29                        {30                            throw ReactError(Error("Should be working on an effect."));31                        }32                    }...StoryReal.js
Source:StoryReal.js  
1import React from 'react';2import Story from "./story";3import './StoryReal.css';4function StoryReal() {5    return (6        <div className="storyReal">7            <Story profileSrc="https://avatars1.githubusercontent.com/u/25810173?s=460&u=75f18d14145fc8bb2c24cf15cb64d211793e42a5&v=4" image="https://www.pentasia.com/rails/active_storage/blobs/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBBaXhwIiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--9b531a296e23edbb0ae0d85e4160a44a71b44f8e/1662_original.jpg" title="Mohib Arsala" />8            <Story profileSrc="https://pbs.twimg.com/profile_images/1053717990171176962/rIDEHTl3_400x400.jpg" image="https://pushinteractions-collegemobileinc.netdna-ssl.com/wp-content/themes/PushInteractions/blogimages/12.jpg" title="Mohib Arsala" />9            <Story profileSrc="https://avatars1.githubusercontent.com/u/25810173?s=460&u=75f18d14145fc8bb2c24cf15cb64d211793e42a5&v=4" image="https://pushinteractions-collegemobileinc.netdna-ssl.com/wp-content/themes/PushInteractions/blogimages/12.jpg" title="Mohib Arsala" />10            <Story profileSrc="https://avatars1.githubusercontent.com/u/25810173?s=460&u=75f18d14145fc8bb2c24cf15cb64d211793e42a5&v=4" image="https://specials-images.forbesimg.com/imageserve/5f302109ffad89f9130e07db/960x0.jpg?cropX1=0&cropX2=4800&cropY1=243&cropY2=2943" title="Mohib Arsala" />11            <Story profileSrc="https://avatars1.githubusercontent.com/u/25810173?s=460&u=75f18d14145fc8bb2c24cf15cb64d211793e42a5&v=4" image="https://images.spot.im/v1/production/fl1o2a0z8voo6xoya1pb" title="Mohib Arsala" />12        </div>13    )14}...Using AI Code Generation
1const { chromium } = require('playwright');2(async () => {3  const browser = await chromium.launch();4  const context = await browser.newContext();5  const page = await context.newPage();6  await page.click('input[name="q"]');7  await page.keyboard.type('Hello World');8  await page.keyboard.press('Enter');9  await page.waitForNavigation();10  await page.screenshot({ path: 'google.png' });11  await browser.close();12})();13const { chromium } = require('playwright');14(async () => {15  const browser = await chromium.launch();16  const context = await browser.newContext();17  const page = await context.newPage();18  await page.click('input[name="q"]');19  await page.keyboard.type('Hello World');20  await page.keyboard.press('Enter');21  await page.waitForNavigation();22  await page.screenshot({ path: 'google.png' });23  await browser.close();24})();25const { chromium } = require('playwright');26(async () => {27  const browser = await chromium.launch();28  const context = await browser.newContext();29  const page = await context.newPage();30  await page.click('input[name="q"]');31  await page.keyboard.type('Hello World');32  await page.keyboard.press('Enter');33  await page.waitForNavigation();34  await page.screenshot({ path: 'google.png' });35  await browser.close();36})();37const { chromium } = require('playwright');38(async () => {39  const browser = await chromium.launch();40  const context = await browser.newContext();41  const page = await context.newPage();42  await page.click('input[name="q"]');43  await page.keyboard.type('Hello World');44  await page.keyboard.press('Enter');45  await page.waitForNavigation();46  await page.screenshot({ path: 'google.png' });47  await browser.close();48})();49const { chromium } =Using AI Code Generation
1const { chromium } = require('playwright');2(async () => {3  const browser = await chromium.launch({ headless: false });4  const context = await browser.newContext();5  const page = await context.newPage();6  await page.pushInteractions([7    {8    },9  ]);10  await page.screenshot({ path: 'example.png' });11  await browser.close();12})();13const { chromium } = require('playwright');14(async () => {15  const browser = await chromium.launch({ headless: false });16  const context = await browser.newContext();17  const page = await context.newPage();18  await page.pushInteractions([19    {20    },21  ]);22  await page.screenshot({ path: 'example.png' });23  await browser.close();24})();25const { chromium } = require('playwright');26(async () => {27  const browser = await chromium.launch({ headless: false });28  const context = await browser.newContext();29  const page = await context.newPage();30  await page.pushInteractions([31    {32    },33  ]);34  await page.screenshot({ path: 'example.png' });35  await browser.close();36})();37const { chromium } = require('playwright');38(async () => {39  const browser = await chromium.launch({ headless: false });40  const context = await browser.newContext();41  const page = await context.newPage();42  await page.pushInteractions([43    {44    },45  ]);46  await page.screenshot({ path: 'example.png' });47  await browser.close();48})();49const { chromium } =Using AI Code Generation
1const { chromium } = require('playwright');2const fs = require('fs');3(async () => {4  const browser = await chromium.launch();5  const context = await browser.newContext();6  const page = await context.newPage();7  const interactions = JSON.parse(fs.readFileSync('interactions.json', 'utf8'));8  await page.pushInteractions(interactions);9  await page.screenshot({ path: 'screenshot.png' });10  await browser.close();11})();12const { chromium } = require('playwright');13const fs = require('fs');14(async () => {15  const browser = await chromium.launch();16  const context = await browser.newContext();17  const page = await context.newPage();18  await page.startTracing();19  await page.click('text=Get Started');20  const interactions = await page.stopTracing();21  fs.writeFileSync('interactions.json', JSON.stringify(interactions), 'utf8');22  await browser.close();23})();Using AI Code Generation
1const { chromium } = require('playwright');2(async () => {3  const browser = await chromium.launch();4  const page = await browser.newPage();5  await page.pushInteractions([6    {7      selector: '#navbar > nav > div:nth-child(1) > a:nth-child(1)',8    },9    {10      selector: '#navbar > nav > div:nth-child(1) > a:nth-child(2)',11    },12    {13      selector: '#navbar > nav > div:nth-child(1) > a:nth-child(3)',14    },15  ]);16  await browser.close();17})();18const { chromium } = require('playwright');19(async () => {20  const browser = await chromium.launch();21  const page = await browser.newPage();22  await page.pushInteractions([23    {24      selector: '#navbar > nav > div:nth-child(1) > a:nth-child(1)',25    },26    {27      selector: '#navbar > nav > div:nth-child(1) > a:nth-child(2)',28    },29    {30      selector: '#navbar > nav > div:nth-child(1) > a:nth-child(3)',31    },32  ]);33  await browser.close();34})();35const { chromium } = require('playwright');36(async () => {37  const browser = await chromium.launch();38  const page = await browser.newPage();39  await page.pushInteractions([40    {41      selector: '#navbar > nav > div:nth-child(1) > a:nth-child(1)',42    },43    {44      selector: '#navbar > nav > div:nth-child(1) > a:nth-child(2)',45    },46    {47      selector: '#navbar > nav > div:nth-child(1) > a:nth-child(3)',48    },49  ]);50  await browser.close();51})();Using AI Code Generation
1const { chromium } = require('playwright-core');2(async () => {3    const browser = await chromium.launch();4    const context = await browser.newContext();5    const page = await context.newPage();6    await page.waitForSelector('input[name="q"]');7    await page.type('input[name="q"]', 'hello world');8    await page.keyboard.press('Enter');9    await page.waitForSelector('text="Hello World"');10    await page.click('text="Hello World"');11    await page.waitForSelector('text="Hello, World!"');12    await page.close();13    await context.close();14    await browser.close();15})();16const { chromium } = require('playwright-core');17(async () => {18    const browser = await chromium.launch();19    const context = await browser.newContext();20    const page = await context.newPage();21    await page.waitForSelector('input[name="q"]');22    await page.type('input[name="q"]', 'hello world');23    await page.keyboard.press('Enter');24    await page.waitForSelector('text="Hello World"');25    await page.click('text="Hello World"');26    await page.waitForSelector('text="Hello, World!"');27    await page.close();28    await context.close();29    await browser.close();30})();31const { chromium } = require('playwright-core');32(async () => {33    const browser = await chromium.launch();34    const context = await browser.newContext();35    const page = await context.newPage();36    await page.waitForSelector('input[name="q"]');37    await page.type('input[name="q"]', 'hello world');38    await page.keyboard.press('Enter');39    await page.waitForSelector('text="Hello World"');40    await page.click('text="Hello World"');41    await page.waitForSelector('text="Hello, World!"');42    await page.close();43    await context.close();44    await browser.close();45})();46const { chromium } = require('playwright-core');47(async () => {Using AI Code Generation
1const { chromium } = require('playwright');2const { pushInteractions } = require('playwright/lib/internal/recorder/recorderActions');3(async () => {4  const browser = await chromium.launch();5  const context = await browser.newContext();6  const page = await context.newPage();7  await pushInteractions(page, [8    {9      position: { x: 0, y: 0 },10    },11  ]);12  await page.screenshot({ path: `example.png` });13  await browser.close();14})();15const { chromium } = require('playwright');16const { pushInteractions } = require('playwright/lib/internal/recorder/recorderActions');17(async () => {18  const browser = await chromium.launch();19  const context = await browser.newContext();20  const page = await context.newPage();21  await pushInteractions(page, [22    {23      position: { x: 0, y: 0 },24    },25  ]);26  await page.screenshot({ path: `example.png` });27  await browser.close();28})();29const { chromium } = require('playwright');30const { pushInteractions } = require('playwright/lib/internal/recorder/recorderActions');31(async () => {32  const browser = await chromium.launch();33  const context = await browser.newContext();34  const page = await context.newPage();35  await pushInteractions(page, [36    {37      position: { x: 0, y: 0 },38    },39  ]);40  await page.screenshot({ path: `example.png` });41  await browser.close();42})();43const {Using AI Code Generation
1const { chromium } = require('playwright');2const { pushInteractions } = require('playwright/lib/internal/recorder/recorderActions');3const fs = require('fs');4(async () => {5  const browser = await chromium.launch();6  const context = await browser.newContext();7  const page = await context.newPage();8  await page.click('input[name="q"]');9  await page.fill('input[name="q"]', 'Hello World');10  await page.press('input[name="q"]', 'Enter');11  const interactions = await pushInteractions();12  fs.writeFileSync('test.json', JSON.stringify(interactions));13  await browser.close();14})();15{16    {17    },18    {19    },20    {21    },22    {23    }24}25const { chromium } = require('playwright');26const { parseInteractions } = require('playwright/lib/internal/recorder/recorderActions');27const fs = require('fs');28(async () => {29  const browser = await chromium.launch();30  const context = await browser.newContext();31  const page = await context.newPage();32  const interactions = fs.readFileSync('test.json', 'utf8');33  await parseInteractions(page, JSON.parse(interactions));34  await browser.close();35})();36{37    {38    },39    {Using AI Code Generation
1const { Playwright } = require('@playwright/test');2const { test, expect, it } = require('@playwright/test');3const { pushInteractions, popInteractions, clearInteractions, interactions } = require('@playwright/test');4const { chromium } = require('playwright');5test.describe('Playwright Internal API', () => {6  test.beforeAll(async ({browserName}) => {7    const browser = await chromium.launch();8    const context = await browser.newContext();9    const page = await context.newPage();10    await page.fill('input[name="q"]', 'Playwright');11    await page.click('input[value="Google Search"]');12    await page.waitForSelector('text=Playwright - Google Search');13    await page.click('text=Playwright - Google Search');14    console.log(interactions().length);15    console.log(interactions());16    clearInteractions();17    console.log(interactions().length);18    console.log(interactions());19    pushInteractions();20    console.log(interactions().length);21    console.log(interactions());22    popInteractions();23    console.log(interactions().length);24    console.log(interactions());25  });26  test('test', async ({page}) => {27    await page.fill('input[name="q"]', 'Playwright');28    await page.click('input[value="Google Search"]');29    await page.waitForSelector('text=Playwright - Google Search');30    await page.click('text=Playwright - Google Search');31  });32});33Your name to display (optional):34Your name to display (optional):35const { Playwright } = require('@playwright/test');36const { test, expect, it } = require('@playwright/test');Using AI Code Generation
1await page.type('#my-input', 'Hello World');2await page.click('#my-button');3const { chromium } = require('playwright');4(async () => {5  const browser = await chromium.launch();6  const context = await browser.newContext();7  const page = await context.newPage();8  await page.screenshot({ path: 'example.png' });9  await browser.close();10})();11const { chromium } = require('playwright');12(async () => {13  const browser = await chromium.launch();14  const context = await browser.newContext();15  const page = await context.newPage();16  await page.screenshot({ path: 'example.png' });17  await browser.close();18})();19const { chromium } = require('playwright');20(async () => {21  const browser = await chromium.launch();22  const context = await browser.newContext();23  const page = await context.newPage();24  await page.screenshot({ path: 'example.png' });25  await browser.close();26})();27const { chromium } = require('playwright');28(async () => {29  const browser = await chromium.launch();30  const context = await browser.newContext();31  const page = await context.newPage();32  await page.screenshot({ path: 'example.png' });33  await browser.close();34})();35const { chromium } = require('playwright');36(async () => {37  const browser = await chromium.launch();38  const context = await browser.newContext();39  const page = await context.newPage();40  await page.screenshot({ path: 'example.png' });41  await browser.close();42})();43const { chromium } = require('playwright');44(async () => {45  const browser = await chromium.launch();LambdaTest’s Playwright tutorial will give you a broader idea about the Playwright automation framework, its unique features, and use cases with examples to exceed your understanding of Playwright testing. This tutorial will give A to Z guidance, from installing the Playwright framework to some best practices and advanced concepts.
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