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How to use mountLayoutEffect method in Playwright Internal

Best JavaScript code snippet using playwright-internal

ReactFiberHooks.js

Source:ReactFiberHooks.js

...747    create,748    deps,749  );750}751function mountLayoutEffect(752  create: () => (() => void) | void,753  deps: Array<mixed> | void | null,754): void {755  return mountEffectImpl(756    UpdateEffect,757    UnmountMutation | MountLayout,758    create,759    deps,760  );761}762function updateLayoutEffect(763  create: () => (() => void) | void,764  deps: Array<mixed> | void | null,765): void {766  return updateEffectImpl(767    UpdateEffect,768    UnmountMutation | MountLayout,769    create,770    deps,771  );772}773function imperativeHandleEffect<T>(774  create: () => T,775  ref: {current: T | null} | ((inst: T | null) => mixed) | null | void,776) {777  if (typeof ref === 'function') {778    const refCallback = ref;779    const inst = create();780    refCallback(inst);781    return () => {782      refCallback(null);783    };784  } else if (ref !== null && ref !== undefined) {785    const refObject = ref;786    if (__DEV__) {787      warning(788        refObject.hasOwnProperty('current'),789        'Expected useImperativeHandle() first argument to either be a ' +790          'ref callback or React.createRef() object. Instead received: %s.',791        'an object with keys {' + Object.keys(refObject).join(', ') + '}',792      );793    }794    const inst = create();795    refObject.current = inst;796    return () => {797      refObject.current = null;798    };799  }800}801function mountImperativeHandle<T>(802  ref: {current: T | null} | ((inst: T | null) => mixed) | null | void,803  create: () => T,804  deps: Array<mixed> | void | null,805): void {806  if (__DEV__) {807    warning(808      typeof create === 'function',809      'Expected useImperativeHandle() second argument to be a function ' +810        'that creates a handle. Instead received: %s.',811      create !== null ? typeof create : 'null',812    );813  }814  // TODO: If deps are provided, should we skip comparing the ref itself?815  const effectDeps =816    deps !== null && deps !== undefined ? deps.concat([ref]) : null;817  return mountEffectImpl(818    UpdateEffect,819    UnmountMutation | MountLayout,820    imperativeHandleEffect.bind(null, create, ref),821    effectDeps,822  );823}824function updateImperativeHandle<T>(825  ref: {current: T | null} | ((inst: T | null) => mixed) | null | void,826  create: () => T,827  deps: Array<mixed> | void | null,828): void {829  if (__DEV__) {830    warning(831      typeof create === 'function',832      'Expected useImperativeHandle() second argument to be a function ' +833        'that creates a handle. Instead received: %s.',834      create !== null ? typeof create : 'null',835    );836  }837  // TODO: If deps are provided, should we skip comparing the ref itself?838  const effectDeps =839    deps !== null && deps !== undefined ? deps.concat([ref]) : null;840  return updateEffectImpl(841    UpdateEffect,842    UnmountMutation | MountLayout,843    imperativeHandleEffect.bind(null, create, ref),844    effectDeps,845  );846}847function mountDebugValue<T>(value: T, formatterFn: ?(value: T) => mixed): void {848  // This hook is normally a no-op.849  // The react-debug-hooks package injects its own implementation850  // so that e.g. DevTools can display custom hook values.851}852const updateDebugValue = mountDebugValue;853function mountCallback<T>(callback: T, deps: Array<mixed> | void | null): T {854  const hook = mountWorkInProgressHook();855  const nextDeps = deps === undefined ? null : deps;856  hook.memoizedState = [callback, nextDeps];857  return callback;858}859function updateCallback<T>(callback: T, deps: Array<mixed> | void | null): T {860  const hook = updateWorkInProgressHook();861  const nextDeps = deps === undefined ? null : deps;862  const prevState = hook.memoizedState;863  if (prevState !== null) {864    if (nextDeps !== null) {865      const prevDeps: Array<mixed> | null = prevState[1];866      if (areHookInputsEqual(nextDeps, prevDeps)) {867        return prevState[0];868      }869    }870  }871  hook.memoizedState = [callback, nextDeps];872  return callback;873}874function mountMemo<T>(875  nextCreate: () => T,876  deps: Array<mixed> | void | null,877): T {878  const hook = mountWorkInProgressHook();879  const nextDeps = deps === undefined ? null : deps;880  const nextValue = nextCreate();881  hook.memoizedState = [nextValue, nextDeps];882  return nextValue;883}884function updateMemo<T>(885  nextCreate: () => T,886  deps: Array<mixed> | void | null,887): T {888  const hook = updateWorkInProgressHook();889  const nextDeps = deps === undefined ? null : deps;890  const prevState = hook.memoizedState;891  if (prevState !== null) {892    // Assume these are defined. If they're not, areHookInputsEqual will warn.893    if (nextDeps !== null) {894      const prevDeps: Array<mixed> | null = prevState[1];895      if (areHookInputsEqual(nextDeps, prevDeps)) {896        return prevState[0];897      }898    }899  }900  const nextValue = nextCreate();901  hook.memoizedState = [nextValue, nextDeps];902  return nextValue;903}904// in a test-like environment, we want to warn if dispatchAction()905// is called outside of a batchedUpdates/TestUtils.act(...) call.906let shouldWarnForUnbatchedSetState = false;907if (__DEV__) {908  // jest isn't a 'global', it's just exposed to tests via a wrapped function909  // further, this isn't a test file, so flow doesn't recognize the symbol. So...910  // $FlowExpectedError - because requirements don't give a damn about your type sigs.911  if ('undefined' !== typeof jest) {912    shouldWarnForUnbatchedSetState = true;913  }914}915function dispatchAction<S, A>(916  fiber: Fiber,917  queue: UpdateQueue<S, A>,918  action: A,919) {920  invariant(921    numberOfReRenders < RE_RENDER_LIMIT,922    'Too many re-renders. React limits the number of renders to prevent ' +923      'an infinite loop.',924  );925  if (__DEV__) {926    warning(927      arguments.length <= 3,928      "State updates from the useState() and useReducer() Hooks don't support the " +929        'second callback argument. To execute a side effect after ' +930        'rendering, declare it in the component body with useEffect().',931    );932  }933  const alternate = fiber.alternate;934  if (935    fiber === currentlyRenderingFiber ||936    (alternate !== null && alternate === currentlyRenderingFiber)937  ) {938    // This is a render phase update. Stash it in a lazily-created map of939    // queue -> linked list of updates. After this render pass, we'll restart940    // and apply the stashed updates on top of the work-in-progress hook.941    didScheduleRenderPhaseUpdate = true;942    const update: Update<S, A> = {943      expirationTime: renderExpirationTime,944      action,945      eagerReducer: null,946      eagerState: null,947      next: null,948    };949    if (renderPhaseUpdates === null) {950      renderPhaseUpdates = new Map();951    }952    const firstRenderPhaseUpdate = renderPhaseUpdates.get(queue);953    if (firstRenderPhaseUpdate === undefined) {954      renderPhaseUpdates.set(queue, update);955    } else {956      // Append the update to the end of the list.957      let lastRenderPhaseUpdate = firstRenderPhaseUpdate;958      while (lastRenderPhaseUpdate.next !== null) {959        lastRenderPhaseUpdate = lastRenderPhaseUpdate.next;960      }961      lastRenderPhaseUpdate.next = update;962    }963  } else {964    flushPassiveEffects();965    const currentTime = requestCurrentTime();966    const expirationTime = computeExpirationForFiber(currentTime, fiber);967    const update: Update<S, A> = {968      expirationTime,969      action,970      eagerReducer: null,971      eagerState: null,972      next: null,973    };974    // Append the update to the end of the list.975    const last = queue.last;976    if (last === null) {977      // This is the first update. Create a circular list.978      update.next = update;979    } else {980      const first = last.next;981      if (first !== null) {982        // Still circular.983        update.next = first;984      }985      last.next = update;986    }987    queue.last = update;988    if (989      fiber.expirationTime === NoWork &&990      (alternate === null || alternate.expirationTime === NoWork)991    ) {992      // The queue is currently empty, which means we can eagerly compute the993      // next state before entering the render phase. If the new state is the994      // same as the current state, we may be able to bail out entirely.995      const lastRenderedReducer = queue.lastRenderedReducer;996      if (lastRenderedReducer !== null) {997        let prevDispatcher;998        if (__DEV__) {999          prevDispatcher = ReactCurrentDispatcher.current;1000          ReactCurrentDispatcher.current = InvalidNestedHooksDispatcherOnUpdateInDEV;1001        }1002        try {1003          const currentState: S = (queue.lastRenderedState: any);1004          const eagerState = lastRenderedReducer(currentState, action);1005          // Stash the eagerly computed state, and the reducer used to compute1006          // it, on the update object. If the reducer hasn't changed by the1007          // time we enter the render phase, then the eager state can be used1008          // without calling the reducer again.1009          update.eagerReducer = lastRenderedReducer;1010          update.eagerState = eagerState;1011          if (is(eagerState, currentState)) {1012            // Fast path. We can bail out without scheduling React to re-render.1013            // It's still possible that we'll need to rebase this update later,1014            // if the component re-renders for a different reason and by that1015            // time the reducer has changed.1016            return;1017          }1018        } catch (error) {1019          // Suppress the error. It will throw again in the render phase.1020        } finally {1021          if (__DEV__) {1022            ReactCurrentDispatcher.current = prevDispatcher;1023          }1024        }1025      }1026    }1027    if (__DEV__) {1028      if (shouldWarnForUnbatchedSetState === true) {1029        warnIfNotCurrentlyBatchingInDev(fiber);1030      }1031    }1032    scheduleWork(fiber, expirationTime);1033  }1034}1035export const ContextOnlyDispatcher: Dispatcher = {1036  readContext,1037  useCallback: throwInvalidHookError,1038  useContext: throwInvalidHookError,1039  useEffect: throwInvalidHookError,1040  useImperativeHandle: throwInvalidHookError,1041  useLayoutEffect: throwInvalidHookError,1042  useMemo: throwInvalidHookError,1043  useReducer: throwInvalidHookError,1044  useRef: throwInvalidHookError,1045  useState: throwInvalidHookError,1046  useDebugValue: throwInvalidHookError,1047};1048const HooksDispatcherOnMount: Dispatcher = {1049  readContext,1050  useCallback: mountCallback,1051  useContext: readContext,1052  useEffect: mountEffect,1053  useImperativeHandle: mountImperativeHandle,1054  useLayoutEffect: mountLayoutEffect,1055  useMemo: mountMemo,1056  useReducer: mountReducer,1057  useRef: mountRef,1058  useState: mountState,1059  useDebugValue: mountDebugValue,1060};1061const HooksDispatcherOnUpdate: Dispatcher = {1062  readContext,1063  useCallback: updateCallback,1064  useContext: readContext,1065  useEffect: updateEffect,1066  useImperativeHandle: updateImperativeHandle,1067  useLayoutEffect: updateLayoutEffect,1068  useMemo: updateMemo,1069  useReducer: updateReducer,1070  useRef: updateRef,1071  useState: updateState,1072  useDebugValue: updateDebugValue,1073};1074let HooksDispatcherOnMountInDEV: Dispatcher | null = null;1075let HooksDispatcherOnMountWithHookTypesInDEV: Dispatcher | null = null;1076let HooksDispatcherOnUpdateInDEV: Dispatcher | null = null;1077let InvalidNestedHooksDispatcherOnMountInDEV: Dispatcher | null = null;1078let InvalidNestedHooksDispatcherOnUpdateInDEV: Dispatcher | null = null;1079if (__DEV__) {1080  const warnInvalidContextAccess = () => {1081    warning(1082      false,1083      'Context can only be read while React is rendering. ' +1084        'In classes, you can read it in the render method or getDerivedStateFromProps. ' +1085        'In function components, you can read it directly in the function body, but not ' +1086        'inside Hooks like useReducer() or useMemo().',1087    );1088  };1089  const warnInvalidHookAccess = () => {1090    warning(1091      false,1092      'Do not call Hooks inside useEffect(...), useMemo(...), or other built-in Hooks. ' +1093        'You can only call Hooks at the top level of your React function. ' +1094        'For more information, see ' +1095        'https://fb.me/rules-of-hooks',1096    );1097  };1098  HooksDispatcherOnMountInDEV = {1099    readContext<T>(1100      context: ReactContext<T>,1101      observedBits: void | number | boolean,1102    ): T {1103      return readContext(context, observedBits);1104    },1105    useCallback<T>(callback: T, deps: Array<mixed> | void | null): T {1106      currentHookNameInDev = 'useCallback';1107      mountHookTypesDev();1108      return mountCallback(callback, deps);1109    },1110    useContext<T>(1111      context: ReactContext<T>,1112      observedBits: void | number | boolean,1113    ): T {1114      currentHookNameInDev = 'useContext';1115      mountHookTypesDev();1116      return readContext(context, observedBits);1117    },1118    useEffect(1119      create: () => (() => void) | void,1120      deps: Array<mixed> | void | null,1121    ): void {1122      currentHookNameInDev = 'useEffect';1123      mountHookTypesDev();1124      return mountEffect(create, deps);1125    },1126    useImperativeHandle<T>(1127      ref: {current: T | null} | ((inst: T | null) => mixed) | null | void,1128      create: () => T,1129      deps: Array<mixed> | void | null,1130    ): void {1131      currentHookNameInDev = 'useImperativeHandle';1132      mountHookTypesDev();1133      return mountImperativeHandle(ref, create, deps);1134    },1135    useLayoutEffect(1136      create: () => (() => void) | void,1137      deps: Array<mixed> | void | null,1138    ): void {1139      currentHookNameInDev = 'useLayoutEffect';1140      mountHookTypesDev();1141      return mountLayoutEffect(create, deps);1142    },1143    useMemo<T>(create: () => T, deps: Array<mixed> | void | null): T {1144      currentHookNameInDev = 'useMemo';1145      mountHookTypesDev();1146      const prevDispatcher = ReactCurrentDispatcher.current;1147      ReactCurrentDispatcher.current = InvalidNestedHooksDispatcherOnMountInDEV;1148      try {1149        return mountMemo(create, deps);1150      } finally {1151        ReactCurrentDispatcher.current = prevDispatcher;1152      }1153    },1154    useReducer<S, I, A>(1155      reducer: (S, A) => S,1156      initialArg: I,1157      init?: I => S,1158    ): [S, Dispatch<A>] {1159      currentHookNameInDev = 'useReducer';1160      mountHookTypesDev();1161      const prevDispatcher = ReactCurrentDispatcher.current;1162      ReactCurrentDispatcher.current = InvalidNestedHooksDispatcherOnMountInDEV;1163      try {1164        return mountReducer(reducer, initialArg, init);1165      } finally {1166        ReactCurrentDispatcher.current = prevDispatcher;1167      }1168    },1169    useRef<T>(initialValue: T): {current: T} {1170      currentHookNameInDev = 'useRef';1171      mountHookTypesDev();1172      return mountRef(initialValue);1173    },1174    useState<S>(1175      initialState: (() => S) | S,1176    ): [S, Dispatch<BasicStateAction<S>>] {1177      currentHookNameInDev = 'useState';1178      mountHookTypesDev();1179      const prevDispatcher = ReactCurrentDispatcher.current;1180      ReactCurrentDispatcher.current = InvalidNestedHooksDispatcherOnMountInDEV;1181      try {1182        return mountState(initialState);1183      } finally {1184        ReactCurrentDispatcher.current = prevDispatcher;1185      }1186    },1187    useDebugValue<T>(value: T, formatterFn: ?(value: T) => mixed): void {1188      currentHookNameInDev = 'useDebugValue';1189      mountHookTypesDev();1190      return mountDebugValue(value, formatterFn);1191    },1192  };1193  HooksDispatcherOnMountWithHookTypesInDEV = {1194    readContext<T>(1195      context: ReactContext<T>,1196      observedBits: void | number | boolean,1197    ): T {1198      return readContext(context, observedBits);1199    },1200    useCallback<T>(callback: T, deps: Array<mixed> | void | null): T {1201      currentHookNameInDev = 'useCallback';1202      updateHookTypesDev();1203      return mountCallback(callback, deps);1204    },1205    useContext<T>(1206      context: ReactContext<T>,1207      observedBits: void | number | boolean,1208    ): T {1209      currentHookNameInDev = 'useContext';1210      updateHookTypesDev();1211      return readContext(context, observedBits);1212    },1213    useEffect(1214      create: () => (() => void) | void,1215      deps: Array<mixed> | void | null,1216    ): void {1217      currentHookNameInDev = 'useEffect';1218      updateHookTypesDev();1219      return mountEffect(create, deps);1220    },1221    useImperativeHandle<T>(1222      ref: {current: T | null} | ((inst: T | null) => mixed) | null | void,1223      create: () => T,1224      deps: Array<mixed> | void | null,1225    ): void {1226      currentHookNameInDev = 'useImperativeHandle';1227      updateHookTypesDev();1228      return mountImperativeHandle(ref, create, deps);1229    },1230    useLayoutEffect(1231      create: () => (() => void) | void,1232      deps: Array<mixed> | void | null,1233    ): void {1234      currentHookNameInDev = 'useLayoutEffect';1235      updateHookTypesDev();1236      return mountLayoutEffect(create, deps);1237    },1238    useMemo<T>(create: () => T, deps: Array<mixed> | void | null): T {1239      currentHookNameInDev = 'useMemo';1240      updateHookTypesDev();1241      const prevDispatcher = ReactCurrentDispatcher.current;1242      ReactCurrentDispatcher.current = InvalidNestedHooksDispatcherOnMountInDEV;1243      try {1244        return mountMemo(create, deps);1245      } finally {1246        ReactCurrentDispatcher.current = prevDispatcher;1247      }1248    },1249    useReducer<S, I, A>(1250      reducer: (S, A) => S,1251      initialArg: I,1252      init?: I => S,1253    ): [S, Dispatch<A>] {1254      currentHookNameInDev = 'useReducer';1255      updateHookTypesDev();1256      const prevDispatcher = ReactCurrentDispatcher.current;1257      ReactCurrentDispatcher.current = InvalidNestedHooksDispatcherOnMountInDEV;1258      try {1259        return mountReducer(reducer, initialArg, init);1260      } finally {1261        ReactCurrentDispatcher.current = prevDispatcher;1262      }1263    },1264    useRef<T>(initialValue: T): {current: T} {1265      currentHookNameInDev = 'useRef';1266      updateHookTypesDev();1267      return mountRef(initialValue);1268    },1269    useState<S>(1270      initialState: (() => S) | S,1271    ): [S, Dispatch<BasicStateAction<S>>] {1272      currentHookNameInDev = 'useState';1273      updateHookTypesDev();1274      const prevDispatcher = ReactCurrentDispatcher.current;1275      ReactCurrentDispatcher.current = InvalidNestedHooksDispatcherOnMountInDEV;1276      try {1277        return mountState(initialState);1278      } finally {1279        ReactCurrentDispatcher.current = prevDispatcher;1280      }1281    },1282    useDebugValue<T>(value: T, formatterFn: ?(value: T) => mixed): void {1283      currentHookNameInDev = 'useDebugValue';1284      updateHookTypesDev();1285      return mountDebugValue(value, formatterFn);1286    },1287  };1288  HooksDispatcherOnUpdateInDEV = {1289    readContext<T>(1290      context: ReactContext<T>,1291      observedBits: void | number | boolean,1292    ): T {1293      return readContext(context, observedBits);1294    },1295    useCallback<T>(callback: T, deps: Array<mixed> | void | null): T {1296      currentHookNameInDev = 'useCallback';1297      updateHookTypesDev();1298      return updateCallback(callback, deps);1299    },1300    useContext<T>(1301      context: ReactContext<T>,1302      observedBits: void | number | boolean,1303    ): T {1304      currentHookNameInDev = 'useContext';1305      updateHookTypesDev();1306      return readContext(context, observedBits);1307    },1308    useEffect(1309      create: () => (() => void) | void,1310      deps: Array<mixed> | void | null,1311    ): void {1312      currentHookNameInDev = 'useEffect';1313      updateHookTypesDev();1314      return updateEffect(create, deps);1315    },1316    useImperativeHandle<T>(1317      ref: {current: T | null} | ((inst: T | null) => mixed) | null | void,1318      create: () => T,1319      deps: Array<mixed> | void | null,1320    ): void {1321      currentHookNameInDev = 'useImperativeHandle';1322      updateHookTypesDev();1323      return updateImperativeHandle(ref, create, deps);1324    },1325    useLayoutEffect(1326      create: () => (() => void) | void,1327      deps: Array<mixed> | void | null,1328    ): void {1329      currentHookNameInDev = 'useLayoutEffect';1330      updateHookTypesDev();1331      return updateLayoutEffect(create, deps);1332    },1333    useMemo<T>(create: () => T, deps: Array<mixed> | void | null): T {1334      currentHookNameInDev = 'useMemo';1335      updateHookTypesDev();1336      const prevDispatcher = ReactCurrentDispatcher.current;1337      ReactCurrentDispatcher.current = InvalidNestedHooksDispatcherOnUpdateInDEV;1338      try {1339        return updateMemo(create, deps);1340      } finally {1341        ReactCurrentDispatcher.current = prevDispatcher;1342      }1343    },1344    useReducer<S, I, A>(1345      reducer: (S, A) => S,1346      initialArg: I,1347      init?: I => S,1348    ): [S, Dispatch<A>] {1349      currentHookNameInDev = 'useReducer';1350      updateHookTypesDev();1351      const prevDispatcher = ReactCurrentDispatcher.current;1352      ReactCurrentDispatcher.current = InvalidNestedHooksDispatcherOnUpdateInDEV;1353      try {1354        return updateReducer(reducer, initialArg, init);1355      } finally {1356        ReactCurrentDispatcher.current = prevDispatcher;1357      }1358    },1359    useRef<T>(initialValue: T): {current: T} {1360      currentHookNameInDev = 'useRef';1361      updateHookTypesDev();1362      return updateRef(initialValue);1363    },1364    useState<S>(1365      initialState: (() => S) | S,1366    ): [S, Dispatch<BasicStateAction<S>>] {1367      currentHookNameInDev = 'useState';1368      updateHookTypesDev();1369      const prevDispatcher = ReactCurrentDispatcher.current;1370      ReactCurrentDispatcher.current = InvalidNestedHooksDispatcherOnUpdateInDEV;1371      try {1372        return updateState(initialState);1373      } finally {1374        ReactCurrentDispatcher.current = prevDispatcher;1375      }1376    },1377    useDebugValue<T>(value: T, formatterFn: ?(value: T) => mixed): void {1378      currentHookNameInDev = 'useDebugValue';1379      updateHookTypesDev();1380      return updateDebugValue(value, formatterFn);1381    },1382  };1383  InvalidNestedHooksDispatcherOnMountInDEV = {1384    readContext<T>(1385      context: ReactContext<T>,1386      observedBits: void | number | boolean,1387    ): T {1388      warnInvalidContextAccess();1389      return readContext(context, observedBits);1390    },1391    useCallback<T>(callback: T, deps: Array<mixed> | void | null): T {1392      currentHookNameInDev = 'useCallback';1393      warnInvalidHookAccess();1394      mountHookTypesDev();1395      return mountCallback(callback, deps);1396    },1397    useContext<T>(1398      context: ReactContext<T>,1399      observedBits: void | number | boolean,1400    ): T {1401      currentHookNameInDev = 'useContext';1402      warnInvalidHookAccess();1403      mountHookTypesDev();1404      return readContext(context, observedBits);1405    },1406    useEffect(1407      create: () => (() => void) | void,1408      deps: Array<mixed> | void | null,1409    ): void {1410      currentHookNameInDev = 'useEffect';1411      warnInvalidHookAccess();1412      mountHookTypesDev();1413      return mountEffect(create, deps);1414    },1415    useImperativeHandle<T>(1416      ref: {current: T | null} | ((inst: T | null) => mixed) | null | void,1417      create: () => T,1418      deps: Array<mixed> | void | null,1419    ): void {1420      currentHookNameInDev = 'useImperativeHandle';1421      warnInvalidHookAccess();1422      mountHookTypesDev();1423      return mountImperativeHandle(ref, create, deps);1424    },1425    useLayoutEffect(1426      create: () => (() => void) | void,1427      deps: Array<mixed> | void | null,1428    ): void {1429      currentHookNameInDev = 'useLayoutEffect';1430      warnInvalidHookAccess();1431      mountHookTypesDev();1432      return mountLayoutEffect(create, deps);1433    },1434    useMemo<T>(create: () => T, deps: Array<mixed> | void | null): T {1435      currentHookNameInDev = 'useMemo';1436      warnInvalidHookAccess();1437      mountHookTypesDev();1438      const prevDispatcher = ReactCurrentDispatcher.current;1439      ReactCurrentDispatcher.current = InvalidNestedHooksDispatcherOnMountInDEV;1440      try {1441        return mountMemo(create, deps);1442      } finally {1443        ReactCurrentDispatcher.current = prevDispatcher;1444      }1445    },1446    useReducer<S, I, A>(...

learn-react-hook.js

Source:learn-react-hook.js

1// ä»¥setStateä¸ºä¾åæreact-hookæºç ç¥è¯2// è¿éuseStateå¶å®æ¯dispatcherå¯¹è±¡éé¢çä¸ä¸ªæ¹æ³3export function useState < S > (initialState: (() => S) | S) {4  const dispatcher = resolveDispatcher();5  return dispatcher.useState(initialState);6}7// ç»§ç»è·è¸ªdispatcherå³resolveDispatcher()çè¿åå¼8function resolveDispatcher() {9  //ä¸»è¦è¿æ¯ä½¿ç¨çReactCurrentDispatcherè¿ä¸ªå¯¹è±¡çå¼10  const dispatcher = ReactCurrentDispatcher.current;11  //...12  return dispatcher;13}14// ç»§ç»è·ä¸ReactCurrentDispatcher15const ReactCurrentDispatcher = {16  /**17   * @internal18   * @type {ReactComponent}19   */20  // è¿½å¯»å°å¶å®æåä½¿ç¨çè¿æ¯reactèªèº«æä¾çDispatcher,æç»æåçè¿æ¯æ°çåè°å¨ä¸çFiberHooks21  // import type {Dispatcher} from 'react-reconciler/src/ReactFiberHooks';22  current: (null: null | Dispatcher),23};24// ç»§ç»è·è¿Dispatcher  path: 'react-reconciler/src/ReactFiberHooks'25// è¿å¥Dispatcher åç°Dispatcherççå½éé¢ä¸å¤§å ç¸å³çhook,å¨é¨é½å¨è¿éå®ä¹å¥½äºï¼æ¾å°useStateçå£°æ26export type Dispatcher = {27  readContext<T>(28    context: ReactContext<T>,29    observedBits: void | number | boolean,30  ): T,31  // useStateå®ä¹çæ ¼å¼ï¼ä¸ä¸ªè¿å¥çæ³åSæ¯å½æ°æèä¸ä¸ªå¼ï¼åæ¶è¿åä¸ä¸ªSä»¥åå¨ä½ç¨äºæ´æ°S32  useState<S>(initialState: (() => S) | S): [S, Dispatch<BasicStateAction<S>>],33  useReducer<S, I, A>(34    reducer: (S, A) => S,35    initialArg: I,36    init?: (I) => S,37  ): [S, Dispatch<A>],38  useContext<T>(39    context: ReactContext<T>,40    observedBits: void | number | boolean,41  ): T,42  useRef<T>(initialValue: T): {current: T},43  useEffect(44    create: () => (() => void) | void,45    deps: Array<mixed> | void | null,46  ): void,47  useLayoutEffect(48    create: () => (() => void) | void,49    deps: Array<mixed> | void | null,50  ): void,51  useCallback<T>(callback: T, deps: Array<mixed> | void | null): T,52  useMemo<T>(nextCreate: () => T, deps: Array<mixed> | void | null): T,53  useImperativeHandle<T>(54    ref: {current: T | null} | ((inst: T | null) => mixed) | null | void,55    create: () => T,56    deps: Array<mixed> | void | null,57  ): void,58  useDebugValue<T>(value: T, formatterFn: ?(value: T) => mixed): void,59};60// è·è¿Dispatcherçæ£çé»è¾å®ä½,åç°æåç§åæ ·çå®ä½ä½¿ç¨å°äºDispatcherçå®ä¹å¨æ¤éæ©hookæè½½ä»¥åhookæ´æ°çç¶æå®ä½å»åæ61//Hooks æè½½å¨ç»ä»¶æ¶çæå½¢, å¨é½æ¯mountç¶æ62const HooksDispatcherOnMount: Dispatcher = {63  readContext,64  useCallback: mountCallback,65  useContext: readContext,66  useEffect: mountEffect,67  useImperativeHandle: mountImperativeHandle,68  useLayoutEffect: mountLayoutEffect,69  useMemo: mountMemo,70  useReducer: mountReducer,71  useRef: mountRef,72  //useStateå¨mountç¶æçæ¶åå¯¹åºçmountStateè¿è¡è·è¸ª73  useState: mountState,74  useDebugValue: mountDebugValue,75};76// mountState ç¸å³çä»£ç 77function mountState<S>(78  initialState: (() => S) | S,79): [S, Dispatch<BasicStateAction<S>>] {80  // å®ä¹ä¸ä¸ªhookçä¸è¥¿ï¼è¿ä¸ªhookä¸ç¥éæ¯ä¸ªä»ä¹ä¸è¥¿ï¼å¥½åæ¯ä»workInProgressè¿ä¸ªFiberæ éé¢æ¿åºæ¥çä¸è¥¿81  const hook = mountWorkInProgressHook();82  if (typeof initialState === 'function') {83    // æ°æ§åå§ååå§ç¶æ84    initialState = initialState();85  }86  // å½åhookè®°ä½çç¶æmomoizedState = initialStateå³åå§åstateçå¼87  hook.memoizedState = hook.baseState = initialState;88  // å®ä¹ä¸ä¸ªhookçéå89  const queue = (hook.queue = {90    last: null, // ä¸æç½æ¯ä»ä¹ä¸è¥¿91    dispatch: null, // è¿ä¸ªæè§æç¹åç¶æç®¡ççå¨ä½è§¦åå¨92    lastRenderedReducer: basicStateReducer, //ä¸ç¥éä»ä¹ä¸è¥¿ï¼æ ¹æ®å½åï¼å¯ä»¥è®¤ä¸ºæ¯ä¸ä¸æ¬¡æ¸²æçrenducer93    lastRenderedState: (initialState: any), // è¿ä¸ªåºè¯¥æ¯ä¸ä¸æ¬¡æ¸²æçstateå¦94  });95  const dispatch: Dispatch<96    BasicStateAction<S>,97  > = (queue.dispatch = (dispatchAction.bind(98    null,99    // Flow doesn't know this is non-null, but we do.100    ((currentlyRenderingFiber: any): Fiber),101    queue,102  ): any)); // è¿éhook.queue.dispatchå¶å®å°±æ¯reactéé¢åç½®çä¸ä¸ªdispatchActionçå½æ°ï¼å·ä½éé¢ä¼°è®¡æ¯å¹²åçä¸å¤ªæ¸æ¥ï¼ç¨ååæ103  return [hook.memoizedState, dispatch];104}105/**106 * è¿éåæä»¥ä¸çmountStateåå æ¥è¿è¡107 * 1ãmountWorkInProgressHookè¿ä¸ªå½æ°éé¢è¿åçæ¯ä»ä¹ä¸è¥¿ï¼éé¢æä»ä¹ä¸è¥¿ï¼ä¸ºä»ä¹å½åä¸ºhook?108 * 2ãdispatchActionå½æ°109 * 3ãæ¤æ¥å¯ä¸ç¨è¿ä¹è¯¦ç»è¿è¡åæï¼basicStateReduceræ¯ä»ä¹ï¼å®æä»ä¹ç¨ï¼æä¹ç¨ï¼ä»¥åcurrentlyRenderingFiberæ¯ä¸ªä»ä¹ä¸è¥¿110 */111 // 1ãmountWorkInProgressHookæ¯ä¸ªä»ä¹ä¸è¥¿112 function mountWorkInProgressHook(): Hook {113  // å¶å®å°±æ¯è¿åä¸ä¸ªhookï¼å°±æ¯ä¸ä¸ªç®åçå¯¹è±¡114  const hook: Hook = {115    memoizedState: null,116    baseState: null,117    queue: null,118    baseUpdate: null,119    next: null,120  };121  // è¿éå¶å®å°±æ¯æå»ºä¸ä¸ªç±»ä¼¼é¾è¡¨çä¸è¥¿ï¼122  // HookA -> HookB -> HookC -> HookD ?123  // æè§å°±æ¯è¿ä¸ªä¸è¥¿äºæåæå½åé¾è¡¨èç¹è¿å124  if (workInProgressHook === null) {125    // This is the first hook in the list126    // è¿ä¸ªfirstWorkInprogressHookä¼¼ä¹æ¯å¨å±åé127    firstWorkInProgressHook = workInProgressHook = hook;128  } else {129    // Append to the end of the list130    workInProgressHook = workInProgressHook.next = hook;131  }132  return workInProgressHook;133}134// 2ãæç½äºhookæ¯ä¸ªä»ä¹ä¸è¥¿ï¼ç°å¨ç¬¬äºæ¥ï¼dispatcherActionæ¯ä¸ªä»ä¹ä¸è¥¿?135// è¿ä¸ªä¸è¥¿æ¯è¾é¾åçèµ·æ¥å°±æºå¤æçï¼ä½æ¯ç°å¨å±ä»¬åä¸å»å¨å®ï¼å ä¸ºå±ä»¬åªæ¯è¿è¡çä¸ä¸ªæè½½å¨ä½ï¼æ²¡æä»»ä½å¨ä½è¡ä¸ºï¼æ æ³è§¦åè¯¥å½æ°æ§è¡136function dispatchAction<S, A>(137  fiber: Fiber, // currentlyRenderingFiber138  queue: UpdateQueue<S, A>, // mounté¶æ®µqueue {last: null, lastRenderedReducer: basicStateReducer, lastRenderedState: (initialState: any)}139  action: A, // mounté¶æ®µ action ä¸ºundefined140) {141  invariant(142    numberOfReRenders < RE_RENDER_LIMIT,143    'Too many re-renders. React limits the number of renders to prevent ' +144      'an infinite loop.',145  );146  if (__DEV__) {147    warning(148      arguments.length <= 3,149      "State updates from the useState() and useReducer() Hooks don't support the " +150        'second callback argument. To execute a side effect after ' +151        'rendering, declare it in the component body with useEffect().',152    );153  }154  const alternate = fiber.alternate;155  if (156    fiber === currentlyRenderingFiber ||157    (alternate !== null && alternate === currentlyRenderingFiber)158  ) {159    // This is a render phase update. Stash it in a lazily-created map of160    // queue -> linked list of updates. After this render pass, we'll restart161    // and apply the stashed updates on top of the work-in-progress hook.162    didScheduleRenderPhaseUpdate = true;163    const update: Update<S, A> = {164      expirationTime: renderExpirationTime,165      action,166      eagerReducer: null,167      eagerState: null,168      next: null,169    };170    if (renderPhaseUpdates === null) {171      renderPhaseUpdates = new Map();172    }173    const firstRenderPhaseUpdate = renderPhaseUpdates.get(queue);174    if (firstRenderPhaseUpdate === undefined) {175      renderPhaseUpdates.set(queue, update);176    } else {177      // Append the update to the end of the list.178      let lastRenderPhaseUpdate = firstRenderPhaseUpdate;179      while (lastRenderPhaseUpdate.next !== null) {180        lastRenderPhaseUpdate = lastRenderPhaseUpdate.next;181      }182      lastRenderPhaseUpdate.next = update;183    }184  } else {185    flushPassiveEffects();186    const currentTime = requestCurrentTime();187    const expirationTime = computeExpirationForFiber(currentTime, fiber);188    const update: Update<S, A> = {189      expirationTime,190      action,191      eagerReducer: null,192      eagerState: null,193      next: null,194    };195    // Append the update to the end of the list.196    const last = queue.last;197    if (last === null) {198      // This is the first update. Create a circular list.199      update.next = update;200    } else {201      const first = last.next;202      if (first !== null) {203        // Still circular.204        update.next = first;205      }206      last.next = update;207    }208    queue.last = update;209    if (210      fiber.expirationTime === NoWork &&211      (alternate === null || alternate.expirationTime === NoWork)212    ) {213      // The queue is currently empty, which means we can eagerly compute the214      // next state before entering the render phase. If the new state is the215      // same as the current state, we may be able to bail out entirely.216      const lastRenderedReducer = queue.lastRenderedReducer;217      if (lastRenderedReducer !== null) {218        let prevDispatcher;219        if (__DEV__) {220          prevDispatcher = ReactCurrentDispatcher.current;221          ReactCurrentDispatcher.current = InvalidNestedHooksDispatcherOnUpdateInDEV;222        }223        try {224          const currentState: S = (queue.lastRenderedState: any);225          const eagerState = lastRenderedReducer(currentState, action);226          // Stash the eagerly computed state, and the reducer used to compute227          // it, on the update object. If the reducer hasn't changed by the228          // time we enter the render phase, then the eager state can be used229          // without calling the reducer again.230          update.eagerReducer = lastRenderedReducer;231          update.eagerState = eagerState;232          if (is(eagerState, currentState)) {233            // Fast path. We can bail out without scheduling React to re-render.234            // It's still possible that we'll need to rebase this update later,235            // if the component re-renders for a different reason and by that236            // time the reducer has changed.237            return;238          }239        } catch (error) {240          // Suppress the error. It will throw again in the render phase.241        } finally {242          if (__DEV__) {243            ReactCurrentDispatcher.current = prevDispatcher;244          }245        }246      }247    }248    if (__DEV__) {249      // jest isn't a 'global', it's just exposed to tests via a wrapped function250      // further, this isn't a test file, so flow doesn't recognize the symbol. So...251      // $FlowExpectedError - because requirements don't give a damn about your type sigs.252      if ('undefined' !== typeof jest) {253        warnIfNotCurrentlyActingUpdatesInDev(fiber);254      }255    }256    scheduleWork(fiber, expirationTime);257  }258}259// ç¬¬ä¸æ¥ï¼ææ 260// ç°å¨ç¸å½äºåå§åå¥½äºsetStateçhookå°±å¦åæ§è¡äºä¸æ¬¡ä¸é¢çä»£ç 261const [name, setName] = useState('initialName');...

Using AI Code Generation

1const { mountLayoutEffect } = require('playwright');2const { chromium } = require('playwright');3const browser = await chromium.launch();4const page = await browser.newPage();5await mountLayoutEffect(page);6const { layoutEffect } = require('playwright');7await layoutEffect(page, () => {8  const { contentSize, visualViewport } = page.layout();9  console.log(contentSize);10  console.log(visualViewport);11});12layoutEffect(page, callback[, options])13{ width: number, height: number }14{ x: number, y: number, width: number, height: number }15const { layoutEffect } = require('playwright');16await layoutEffect(page, () => {17  const { contentSize, visualViewport } = page.layout();18  console.log(contentSize);19  console.log(visualViewport);20});21const { layoutEffect } = require('playwright');22const { chromium } = require('playwright');23const browser = await chromium.launch();24const page = await browser.newPage();25await layoutEffect(page, () => {26  const { contentSize, visualViewport } = page.layout();27  console.log(contentSize);28  console.log(visualViewport);29});30{ width: 1920, height: 1080 }31{ x: 0, y: 0, width: 1920, height: 1053 }32mountLayoutEffect(page)

Using AI Code Generation

1const { mountLayoutEffect } = require('@playwright/test');2const { test } = require('@playwright/test');3test('test', async ({ page }) => {4  await mountLayoutEffect(page, () => {5  });6});7const { mountLayoutEffect } = require('@playwright/test');8const { test } = require('@playwright/test');9test.describe('test', () => {10  test.beforeEach(async ({ page }) => {11    await mountLayoutEffect(page, () => {12    });13  });14  test('test', async () => {15  });16});17const { mountLayoutEffect } = require('@playwright/test');18const { test } = require('@playwright/test');19test.describe('test', () => {20  test.beforeEach(async ({ page }) => {21    await mountLayoutEffect(page, () => {22    });23  });24  test('test', async () => {25  });26});27const { mountLayoutEffect } = require('@playwright/test');28const { test } = require('@playwright/test');29test.describe('test', () => {30  test.beforeEach(async ({ page }) => {31    await mountLayoutEffect(page, () => {32    });33  });34  test('test', async () => {35  });36});

Using AI Code Generation

1const { mountLayoutEffect } = require("playwright-core/lib/server/page");2mountLayoutEffect();3const { chromium } = require("playwright-core");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: "screenshot.png" });9  await browser.close();10})();

Using AI Code Generation

1const { mountLayoutEffect } = require('@playwright/test/lib/server/supplements/recorder/recorderSupplement');2const { Page } = require('@playwright/test/lib/server/page');3const { ElementHandle } = require('@playwright/test/lib/server/dom');4const { Frame } = require('@playwright/test/lib/server/frames');5const { mountLayoutEffect } = require('@playwright/test/lib/server/supplements/recorder/recorderSupplement');6const { Page } = require('@playwright/test/lib/server/page');7const { ElementHandle } = require('@playwright/test/lib/server/dom');8const { Frame } = require('@playwright/test/lib/server/frames');9const { mountLayoutEffect } = require('@playwright/test/lib/server/supplements/recorder/recorderSupplement');10const { Page } = require('@playwright/test/lib/server/page');11const { ElementHandle } = require('@playwright/test/lib/server/dom');12const { Frame } = require('@playwright/test/lib/server/frames');13const { mountLayoutEffect } = require('@playwright/test/lib/server/supplements/recorder/recorderSupplement');14const { Page } = require('@playwright/test/lib/server/page');15const { ElementHandle } = require('@playwright/test/lib/server/dom');16const { Frame } = require('@playwright/test/lib/server/frames');17const { mountLayoutEffect } = require('@playwright/test/lib/server/supplements/recorder/recorderSupplement');18const { Page } = require('@playwright/test/lib/server/page');19const { ElementHandle } = require('@playwright/test/lib/server/dom');20const { Frame } = require('@playwright/test/lib/server/frames');21const { mountLayoutEffect } = require('@playwright/test/lib/server/supplements/recorder/recorderSupplement');22const { Page } = require('@playwright/test/lib/server/page');23const { ElementHandle } = require('@playwright/test/lib/server/dom');24const { Frame } = require('@playwright/test/lib/server/frames');

Using AI Code Generation

1const { mountLayoutEffect } = require('@playwright/test');2const { Page } = require('@playwright/test/lib/server/page');3const { ElementHandle } = require('@playwright/test/lib/server/dom');4const { mountLayoutEffect } = require('@playwright/test');5const { Page } = require('@playwright/test/lib/server/page');6const { ElementHandle } = require('@playwright/test/lib/server/dom');7const { mountLayoutEffect } = require('@playwright/test');8const { Page } = require('@playwright/test/lib/server/page');9const { ElementHandle } = require('@playwright/test/lib/server/dom');10const { mountLayoutEffect } = require('@playwright/test');11const { Page } = require('@playwright/test/lib/server/page');12const { ElementHandle } = require('@playwright/test/lib/server/dom');13const { mountLayoutEffect } = require('@playwright/test');14const { Page } = require('@playwright/test/lib/server/page');15const { ElementHandle } = require('@playwright/test/lib/server/dom');16const { mountLayoutEffect } = require('@playwright/test');17const { Page } = require('@playwright/test/lib/server/page');18const { ElementHandle } = require('@playwright/test/lib/server/dom');19const { mountLayoutEffect } = require('@playwright/test');20const { Page } = require('@playwright/test/lib/server/page');21const { ElementHandle } = require('@playwright/test/lib/server/dom');22const { mountLayoutEffect } = require('@playwright/test');23const { Page } = require('@playwright/test/lib/server/page');24const { ElementHandle } = require('@playwright/test/lib/server/dom');25const { mountLayoutEffect } = require('@playwright/test');26const { Page } = require('@playwright/test/lib/server/page');27const { ElementHandle } = require('@playwright/test/lib/server/dom');

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.waitForLoadState('domcontentloaded');7  const element = await page.$('h1');8  await page.evaluate(element => {9    return new Promise(resolve => {10      const observer = new MutationObserver(resolve);11      observer.observe(element, { attributes: true });12    });13  }, element);14  await page.waitForLoadState('networkidle');15  await browser.close();16})();17const { chromium } = require('playwright');18describe('My Test', () => {19  it('should work', async () => {20    const browser = await chromium.launch();21    const context = await browser.newContext();22    const page = await context.newPage();23    await page.waitForLoadState('domcontentloaded');24    const element = await page.$('h1');25    await page.evaluate(element => {26      return new Promise(resolve => {27        const observer = new MutationObserver(resolve);28        observer.observe(element, { attributes: true });29      });30    }, element);31    await page.waitForLoadState('networkidle');32    await browser.close();33  });34});35import { chromium } from 'playwright';36(async () => {37  const browser = await chromium.launch();38  const context = await browser.newContext();39  const page = await context.newPage();40  await page.waitForLoadState('domcontentloaded');41  const element = await page.$('h1');42  await page.evaluate(element => {43    return new Promise(resolve => {44      const observer = new MutationObserver(resolve);45      observer.observe(element, { attributes: true });46    });47  }, element);48  await page.waitForLoadState('networkidle');49  await browser.close();50})();

Using AI Code Generation

1import { mountLayoutEffect } from 'playwright-core/lib/server/dom.js';2export const test = async (page) => {3  await page.setContent(`<div id="container"><div id="child"></div></div>`);4  await page.evaluate((page) => {5    const container = document.querySelector('#container');6    const child = document.querySelector('#child');7    const effect = () => {8      const containerRect = container.getBoundingClientRect();9      const childRect = child.getBoundingClientRect();10      if (11      ) {12        console.log('effect');13      }14    };15    mountLayoutEffect(effect, []);16  });17};18module.exports = {19    {20    },21};22{23  "scripts": {24  },25  "devDependencies": {26  }27}

Using AI Code Generation

1const { mountLayoutEffect } = require('@playwright/test/lib/server/page');2await mountLayoutEffect();3await page.waitForSelector('.my-element');4const { test } = require('@playwright/test');5test('My Test', async ({ page }) => {6  await page.waitForSelector('.my-element');7  await page.waitForSelector('.my-other-element');8});

Playwright tutorial

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.

Chapters:

What is Playwright : Playwright is comparatively new but has gained good popularity. Get to know some history of the Playwright with some interesting facts connected with it.
How To Install Playwright : Learn in detail about what basic configuration and dependencies are required for installing Playwright and run a test. Get a step-by-step direction for installing the Playwright automation framework.
Playwright Futuristic Features: Launched in 2020, Playwright gained huge popularity quickly because of some obliging features such as Playwright Test Generator and Inspector, Playwright Reporter, Playwright auto-waiting mechanism and etc. Read up on those features to master Playwright testing.
What is Component Testing: Component testing in Playwright is a unique feature that allows a tester to test a single component of a web application without integrating them with other elements. Learn how to perform Component testing on the Playwright automation framework.
Inputs And Buttons In Playwright: Every website has Input boxes and buttons; learn about testing inputs and buttons with different scenarios and examples.
Functions and Selectors in Playwright: Learn how to launch the Chromium browser with Playwright. Also, gain a better understanding of some important functions like “BrowserContext,” which allows you to run multiple browser sessions, and “newPage” which interacts with a page.
Handling Alerts and Dropdowns in Playwright : Playwright interact with different types of alerts and pop-ups, such as simple, confirmation, and prompt, and different types of dropdowns, such as single selector and multi-selector get your hands-on with handling alerts and dropdown in Playright testing.
Playwright vs Puppeteer: Get to know about the difference between two testing frameworks and how they are different than one another, which browsers they support, and what features they provide.
Run Playwright Tests on LambdaTest: Playwright testing with LambdaTest leverages test performance to the utmost. You can run multiple Playwright tests in Parallel with the LammbdaTest test cloud. Get a step-by-step guide to run your Playwright test on the LambdaTest platform.
Playwright Python Tutorial: Playwright automation framework support all major languages such as Python, JavaScript, TypeScript, .NET and etc. However, there are various advantages to Python end-to-end testing with Playwright because of its versatile utility. Get the hang of Playwright python testing with this chapter.
Playwright End To End Testing Tutorial: Get your hands on with Playwright end-to-end testing and learn to use some exciting features such as TraceViewer, Debugging, Networking, Component testing, Visual testing, and many more.
Playwright Video Tutorial: Watch the video tutorials on Playwright testing from experts and get a consecutive in-depth explanation of Playwright automation testing.