@samitouri / QOS-React / commits / a0733fe13d

pure (#13748)

* pure A higher-order component version of the `React.PureComponent` class. During an update, the previous props are compared to the new props. If they are the same, React will skip rendering the component and its children. Unlike userspace implementations, `pure` will not add an additional fiber to the tree. The first argument must be a functional component; it does not work with classes. `pure` uses shallow comparison by default, like `React.PureComponent`. A custom comparison can be passed as the second argument. Co-authored-by: Andrew Clark <acdlite@fb.com> Co-authored-by: Sophie Alpert <sophiebits@fb.com> * Warn if first argument is not a functional component

Andrew Clark committed Sep 27, 2018 at 15:25 UTC a0733fe13d598303f45b9d27c84ce0ec40d09021

10 files changed +433 -70

packages/react-reconciler/src/ReactFiber.js

+15 -14

@@ -37,6 +37,8 @@ import {

37 FunctionalComponentLazy,

38 ClassComponentLazy,

39 ForwardRefLazy,

40 + PureComponent,

41 + PureComponentLazy,

42 } from 'shared/ReactWorkTags';

43 import getComponentName from 'shared/getComponentName';

@@ -57,6 +59,7 @@ import {

59 REACT_CONTEXT_TYPE,

60 REACT_CONCURRENT_MODE_TYPE,

61 REACT_PLACEHOLDER_TYPE,

62 + REACT_PURE_TYPE,

63 } from 'shared/ReactSymbols';

65 let hasBadMapPolyfill;

@@ -300,12 +303,14 @@ export function resolveLazyComponentTag(

303 return shouldConstruct(Component)

304 ? ClassComponentLazy

305 : FunctionalComponentLazy;

303 - } else if (

304 - Component !== undefined &&

305 - Component !== null &&

306 - Component.$$typeof

307 - ) {

308 - return ForwardRefLazy;

306 + } else if (Component !== undefined && Component !== null) {

307 + const $$typeof = Component.$$typeof;

308 + if ($$typeof === REACT_FORWARD_REF_TYPE) {

309 + return ForwardRefLazy;

310 + }

311 + if ($$typeof === REACT_PURE_TYPE) {

312 + return PureComponentLazy;

313 + }

314 }

315 return IndeterminateComponent;

316 }

@@ -363,15 +368,8 @@ export function createWorkInProgress(

368 }

369 }

370

366 - // Don't touching the subtree's expiration time, which has not changed.

371 workInProgress.childExpirationTime = current.childExpirationTime;

368 - if (pendingProps !== current.pendingProps) {

369 - // This fiber has new props.

370 - workInProgress.expirationTime = expirationTime;

371 - } else {

372 - // This fiber's props have not changed.

373 - workInProgress.expirationTime = current.expirationTime;

374 - }

372 + workInProgress.expirationTime = current.expirationTime;

373

374 workInProgress.child = current.child;

375 workInProgress.memoizedProps = current.memoizedProps;

@@ -460,6 +458,9 @@ export function createFiberFromElement(

458 case REACT_FORWARD_REF_TYPE:

459 fiberTag = ForwardRef;

460 break getTag;

461 + case REACT_PURE_TYPE:

462 + fiberTag = PureComponent;

463 + break getTag;

464 default: {

465 if (typeof type.then === 'function') {

466 fiberTag = IndeterminateComponent;

packages/react-reconciler/src/ReactFiberBeginWork.js

+163 -55

@@ -31,6 +31,8 @@ import {

31 ContextConsumer,

32 Profiler,

33 PlaceholderComponent,

34 + PureComponent,

35 + PureComponentLazy,

36 } from 'shared/ReactWorkTags';

37 import {

38 NoEffect,

@@ -52,6 +54,7 @@ import {

54 enableSchedulerTracing,

55 } from 'shared/ReactFeatureFlags';

56 import invariant from 'shared/invariant';

57 +import shallowEqual from 'shared/shallowEqual';

58 import getComponentName from 'shared/getComponentName';

59 import ReactStrictModeWarnings from './ReactStrictModeWarnings';

60 import warning from 'shared/warning';

@@ -196,6 +199,58 @@ function updateForwardRef(

199 return workInProgress.child;

200 }

201

202 +function updatePureComponent(

203 + current: Fiber | null,

204 + workInProgress: Fiber,

205 + Component: any,

206 + nextProps: any,

207 + updateExpirationTime,

208 + renderExpirationTime: ExpirationTime,

209 +) {

210 + const render = Component.render;

211 +

212 + if (

213 + current !== null &&

214 + (updateExpirationTime === NoWork ||

215 + updateExpirationTime > renderExpirationTime)

216 + ) {

217 + const prevProps = current.memoizedProps;

218 + // Default to shallow comparison

219 + let compare = Component.compare;

220 + compare = compare !== null ? compare : shallowEqual;

221 + if (compare(prevProps, nextProps)) {

222 + return bailoutOnAlreadyFinishedWork(

223 + current,

224 + workInProgress,

225 + renderExpirationTime,

226 + );

227 + }

228 + }

229 +

230 + // The rest is a fork of updateFunctionalComponent

231 + let nextChildren;

232 + prepareToReadContext(workInProgress, renderExpirationTime);

233 + if (__DEV__) {

234 + ReactCurrentOwner.current = workInProgress;

235 + ReactCurrentFiber.setCurrentPhase('render');

236 + nextChildren = render(nextProps);

237 + ReactCurrentFiber.setCurrentPhase(null);

238 + } else {

239 + nextChildren = render(nextProps);

240 + }

241 +

242 + // React DevTools reads this flag.

243 + workInProgress.effectTag |= PerformedWork;

244 + reconcileChildren(

245 + current,

246 + workInProgress,

247 + nextChildren,

248 + renderExpirationTime,

249 + );

250 + memoizeProps(workInProgress, nextProps);

251 + return workInProgress.child;

252 +}

253 +

254 function updateFragment(

255 current: Fiber | null,

256 workInProgress: Fiber,

@@ -617,6 +672,7 @@ function mountIndeterminateComponent(

672 current,

673 workInProgress,

674 Component,

675 + updateExpirationTime,

676 renderExpirationTime,

677 ) {

678 invariant(

@@ -637,37 +693,53 @@ function mountIndeterminateComponent(

693 Component,

694 ));

695 const resolvedProps = resolveDefaultProps(Component, props);

696 + let child;

697 switch (resolvedTag) {

698 case FunctionalComponentLazy: {

642 - return updateFunctionalComponent(

699 + child = updateFunctionalComponent(

700 current,

701 workInProgress,

702 Component,

703 resolvedProps,

704 renderExpirationTime,

705 );

706 + break;

707 }

708 case ClassComponentLazy: {

651 - return updateClassComponent(

709 + child = updateClassComponent(

710 current,

711 workInProgress,

712 Component,

713 resolvedProps,

714 renderExpirationTime,

715 );

716 + break;

717 }

718 case ForwardRefLazy: {

660 - return updateForwardRef(

719 + child = updateForwardRef(

720 current,

721 workInProgress,

722 Component,

723 resolvedProps,

724 renderExpirationTime,

725 );

726 + break;

727 + }

728 + case PureComponentLazy: {

729 + child = updatePureComponent(

730 + current,

731 + workInProgress,

732 + Component,

733 + resolvedProps,

734 + updateExpirationTime,

735 + renderExpirationTime,

736 + );

737 + break;

738 }

739 default: {

669 - // This message intentionally doesn't metion ForwardRef because the

670 - // fact that it's a separate type of work is an implementation detail.

740 + // This message intentionally doesn't metion ForwardRef or PureComponent

741 + // because the fact that it's a separate type of work is an

742 + // implementation detail.

743 invariant(

744 false,

745 'Element type is invalid. Received a promise that resolves to: %s. ' +

@@ -676,6 +748,8 @@ function mountIndeterminateComponent(

748 );

749 }

750 }

751 + workInProgress.memoizedProps = props;

752 + return child;

753 }

754

755 const unmaskedContext = getUnmaskedContext(workInProgress, Component, false);

@@ -1106,59 +1180,65 @@ function beginWork(

1180 renderExpirationTime: ExpirationTime,

1181 ): Fiber | null {

1182 const updateExpirationTime = workInProgress.expirationTime;

1109 - if (

1110 - !hasLegacyContextChanged() &&

1111 - (updateExpirationTime === NoWork ||

1112 - updateExpirationTime > renderExpirationTime)

1113 - ) {

1114 - // This fiber does not have any pending work. Bailout without entering

1115 - // the begin phase. There's still some bookkeeping we that needs to be done

1116 - // in this optimized path, mostly pushing stuff onto the stack.

1117 - switch (workInProgress.tag) {

1118 - case HostRoot:

1119 - pushHostRootContext(workInProgress);

1120 - resetHydrationState();

1121 - break;

1122 - case HostComponent:

1123 - pushHostContext(workInProgress);

1124 - break;

1125 - case ClassComponent: {

1126 - const Component = workInProgress.type;

1127 - if (isLegacyContextProvider(Component)) {

1128 - pushLegacyContextProvider(workInProgress);

1183 +

1184 + if (current !== null) {

1185 + const oldProps = current.memoizedProps;

1186 + const newProps = workInProgress.pendingProps;

1187 + if (

1188 + oldProps === newProps &&

1189 + !hasLegacyContextChanged() &&

1190 + (updateExpirationTime === NoWork ||

1191 + updateExpirationTime > renderExpirationTime)

1192 + ) {

1193 + // This fiber does not have any pending work. Bailout without entering

1194 + // the begin phase. There's still some bookkeeping we that needs to be done

1195 + // in this optimized path, mostly pushing stuff onto the stack.

1196 + switch (workInProgress.tag) {

1197 + case HostRoot:

1198 + pushHostRootContext(workInProgress);

1199 + resetHydrationState();

1200 + break;

1201 + case HostComponent:

1202 + pushHostContext(workInProgress);

1203 + break;

1204 + case ClassComponent: {

1205 + const Component = workInProgress.type;

1206 + if (isLegacyContextProvider(Component)) {

1207 + pushLegacyContextProvider(workInProgress);

1208 + }

1209 + break;

1210 }

1130 - break;

1131 - }

1132 - case ClassComponentLazy: {

1133 - const thenable = workInProgress.type;

1134 - const Component = getResultFromResolvedThenable(thenable);

1135 - if (isLegacyContextProvider(Component)) {

1136 - pushLegacyContextProvider(workInProgress);

1211 + case ClassComponentLazy: {

1212 + const thenable = workInProgress.type;

1213 + const Component = getResultFromResolvedThenable(thenable);

1214 + if (isLegacyContextProvider(Component)) {

1215 + pushLegacyContextProvider(workInProgress);

1216 + }

1217 + break;

1218 }

1138 - break;

1139 - }

1140 - case HostPortal:

1141 - pushHostContainer(

1142 - workInProgress,

1143 - workInProgress.stateNode.containerInfo,

1144 - );

1145 - break;

1146 - case ContextProvider: {

1147 - const newValue = workInProgress.memoizedProps.value;

1148 - pushProvider(workInProgress, newValue);

1149 - break;

1150 - }

1151 - case Profiler:

1152 - if (enableProfilerTimer) {

1153 - workInProgress.effectTag |= Update;

1219 + case HostPortal:

1220 + pushHostContainer(

1221 + workInProgress,

1222 + workInProgress.stateNode.containerInfo,

1223 + );

1224 + break;

1225 + case ContextProvider: {

1226 + const newValue = workInProgress.memoizedProps.value;

1227 + pushProvider(workInProgress, newValue);

1228 + break;

1229 }

1155 - break;

1230 + case Profiler:

1231 + if (enableProfilerTimer) {

1232 + workInProgress.effectTag |= Update;

1233 + }

1234 + break;

1235 + }

1236 + return bailoutOnAlreadyFinishedWork(

1237 + current,

1238 + workInProgress,

1239 + renderExpirationTime,

1240 + );

1241 }

1157 - return bailoutOnAlreadyFinishedWork(

1158 - current,

1159 - workInProgress,

1160 - renderExpirationTime,

1161 - );

1242 }

1243

1244 // Before entering the begin phase, clear the expiration time.

@@ -1171,6 +1251,7 @@ function beginWork(

1251 current,

1252 workInProgress,

1253 Component,

1254 + updateExpirationTime,

1255 renderExpirationTime,

1256 );

1257 }

@@ -1252,7 +1333,7 @@ function beginWork(

1333 renderExpirationTime,

1334 );

1335 }

1255 - case ForwardRefLazy:

1336 + case ForwardRefLazy: {

1337 const thenable = workInProgress.type;

1338 const Component = getResultFromResolvedThenable(thenable);

1339 const unresolvedProps = workInProgress.pendingProps;

@@ -1265,6 +1346,7 @@ function beginWork(

1346 );

1347 workInProgress.memoizedProps = unresolvedProps;

1348 return child;

1349 + }

1350 case Fragment:

1351 return updateFragment(current, workInProgress, renderExpirationTime);

1352 case Mode:

@@ -1283,6 +1365,32 @@ function beginWork(

1365 workInProgress,

1366 renderExpirationTime,

1367 );

1368 + case PureComponent: {

1369 + const type = workInProgress.type;

1370 + return updatePureComponent(

1371 + current,

1372 + workInProgress,

1373 + type,

1374 + workInProgress.pendingProps,

1375 + updateExpirationTime,

1376 + renderExpirationTime,

1377 + );

1378 + }

1379 + case PureComponentLazy: {

1380 + const thenable = workInProgress.type;

1381 + const Component = getResultFromResolvedThenable(thenable);

1382 + const unresolvedProps = workInProgress.pendingProps;

1383 + const child = updatePureComponent(

1384 + current,

1385 + workInProgress,

1386 + Component,

1387 + resolveDefaultProps(Component, unresolvedProps),

1388 + updateExpirationTime,

1389 + renderExpirationTime,

1390 + );

1391 + workInProgress.memoizedProps = unresolvedProps;

1392 + return child;

1393 + }

1394 default:

1395 invariant(

1396 false,

packages/react-reconciler/src/ReactFiberCompleteWork.js

@@ -36,6 +36,8 @@ import {

36 Profiler,

37 PlaceholderComponent,

38 ForwardRefLazy,

39 + PureComponent,

40 + PureComponentLazy,

41 } from 'shared/ReactWorkTags';

42 import {Placement, Ref, Update} from 'shared/ReactSideEffectTags';

43 import invariant from 'shared/invariant';

@@ -524,6 +526,9 @@ function completeWork(

526 break;

527 case ContextConsumer:

528 break;

529 + case PureComponent:

530 + case PureComponentLazy:

531 + break;

532 // Error cases

533 case IndeterminateComponent:

534 invariant(

packages/react-reconciler/src/__tests__/ReactPure-test.internal.js new

+194

@@ -0,0 +1,194 @@

1 +/**

3 + *

4 + * This source code is licensed under the MIT license found in the

5 + * LICENSE file in the root directory of this source tree.

6 + *

7 + * @emails react-core

8 + * @jest-environment node

9 + */

10 +

11 +/* eslint-disable no-func-assign */

12 +

13 +'use strict';

14 +

15 +let React;

16 +let ReactFeatureFlags;

17 +let ReactNoop;

18 +

19 +describe('pure', () => {

20 + beforeEach(() => {

21 + jest.resetModules();

22 + ReactFeatureFlags = require('shared/ReactFeatureFlags');

23 + ReactFeatureFlags.debugRenderPhaseSideEffectsForStrictMode = false;

24 + ReactFeatureFlags.enableSuspense = true;

25 + React = require('react');

26 + ReactNoop = require('react-noop-renderer');

27 + });

28 +

29 + function span(prop) {

30 + return {type: 'span', children: [], prop};

31 + }

32 +

33 + function Text(props) {

34 + ReactNoop.yield(props.text);

35 + return <span prop={props.text} />;

36 + }

37 +

38 + // Tests should run against both the lazy and non-lazy versions of `pure`.

39 + // To make the tests work for both versions, we wrap the non-lazy verion in

40 + // a lazy function component.

41 + sharedTests('normal', (...args) => {

42 + const Pure = React.pure(...args);

43 + function Indirection(props) {

44 + return <Pure {...props} />;

45 + }

46 + return Promise.resolve(Indirection);

47 + });

48 + sharedTests('lazy', (...args) => Promise.resolve(React.pure(...args)));

49 +

50 + function sharedTests(label, pure) {

51 + describe(`${label}`, () => {

52 + it('bails out on props equality', async () => {

53 + const {Placeholder} = React;

54 +

55 + function Counter({count}) {

56 + return <Text text={count} />;

57 + }

58 + Counter = pure(Counter);

59 +

60 + ReactNoop.render(

61 + <Placeholder>

62 + <Counter count={0} />

63 + </Placeholder>,

64 + );

65 + expect(ReactNoop.flush()).toEqual([]);

66 + await Promise.resolve();

67 + expect(ReactNoop.flush()).toEqual([0]);

68 + expect(ReactNoop.getChildren()).toEqual([span(0)]);

69 +

70 + // Should bail out because props have not changed

71 + ReactNoop.render(

72 + <Placeholder>

73 + <Counter count={0} />

74 + </Placeholder>,

75 + );

76 + expect(ReactNoop.flush()).toEqual([]);

77 + expect(ReactNoop.getChildren()).toEqual([span(0)]);

78 +

79 + // Should update because count prop changed

80 + ReactNoop.render(

81 + <Placeholder>

82 + <Counter count={1} />

83 + </Placeholder>,

84 + );

85 + expect(ReactNoop.flush()).toEqual([1]);

86 + expect(ReactNoop.getChildren()).toEqual([span(1)]);

87 + });

88 + });

89 +

90 + it("does not bail out if there's a context change", async () => {

91 + const {Placeholder} = React;

92 +

93 + const CountContext = React.createContext(0);

94 +

95 + function Counter(props) {

96 + const count = CountContext.unstable_read();

97 + return <Text text={`${props.label}: ${count}`} />;

98 + }

99 + Counter = pure(Counter);

100 +

101 + class Parent extends React.Component {

102 + state = {count: 0};

103 + render() {

104 + return (

105 + <Placeholder>

106 + <CountContext.Provider value={this.state.count}>

107 + <Counter label="Count" />

108 + </CountContext.Provider>

109 + </Placeholder>

110 + );

111 + }

112 + }

113 +

114 + const parent = React.createRef(null);

115 + ReactNoop.render(<Parent ref={parent} />);

116 + expect(ReactNoop.flush()).toEqual([]);

117 + await Promise.resolve();

118 + expect(ReactNoop.flush()).toEqual(['Count: 0']);

119 + expect(ReactNoop.getChildren()).toEqual([span('Count: 0')]);

120 +

121 + // Should bail out because props have not changed

122 + ReactNoop.render(<Parent ref={parent} />);

123 + expect(ReactNoop.flush()).toEqual([]);

124 + expect(ReactNoop.getChildren()).toEqual([span('Count: 0')]);

125 +

126 + // Should update because there was a context change

127 + parent.current.setState({count: 1});

128 + expect(ReactNoop.flush()).toEqual(['Count: 1']);

129 + expect(ReactNoop.getChildren()).toEqual([span('Count: 1')]);

130 + });

131 +

132 + it('accepts custom comparison function', async () => {

133 + const {Placeholder} = React;

134 +

135 + function Counter({count}) {

136 + return <Text text={count} />;

137 + }

138 + Counter = pure(Counter, (oldProps, newProps) => {

139 + ReactNoop.yield(

140 + `Old count: ${oldProps.count}, New count: ${newProps.count}`,

141 + );

142 + return oldProps.count === newProps.count;

143 + });

144 +

145 + ReactNoop.render(

146 + <Placeholder>

147 + <Counter count={0} />

148 + </Placeholder>,

149 + );

150 + expect(ReactNoop.flush()).toEqual([]);

151 + await Promise.resolve();

152 + expect(ReactNoop.flush()).toEqual([0]);

153 + expect(ReactNoop.getChildren()).toEqual([span(0)]);

154 +

155 + // Should bail out because props have not changed

156 + ReactNoop.render(

157 + <Placeholder>

158 + <Counter count={0} />

159 + </Placeholder>,

160 + );

161 + expect(ReactNoop.flush()).toEqual(['Old count: 0, New count: 0']);

162 + expect(ReactNoop.getChildren()).toEqual([span(0)]);

163 +

164 + // Should update because count prop changed

165 + ReactNoop.render(

166 + <Placeholder>

167 + <Counter count={1} />

168 + </Placeholder>,

169 + );

170 + expect(ReactNoop.flush()).toEqual(['Old count: 0, New count: 1', 1]);

171 + expect(ReactNoop.getChildren()).toEqual([span(1)]);

172 + });

173 +

174 + it('warns for class components', () => {

175 + class SomeClass extends React.Component {

176 + render() {

177 + return null;

178 + }

179 + }

180 + expect(() => pure(SomeClass)).toWarnDev(

181 + 'pure: The first argument must be a functional component.',

182 + {withoutStack: true},

183 + );

184 + });

185 +

186 + it('warns if first argument is not a function', () => {

187 + expect(() => pure()).toWarnDev(

188 + 'pure: The first argument must be a functional component. Instead ' +

189 + 'received: undefined',

190 + {withoutStack: true},

191 + );

192 + });

193 + }

194 +});

packages/react-test-renderer/src/ReactTestRenderer.js

@@ -30,6 +30,8 @@ import {

30 ForwardRef,

31 Profiler,

32 ForwardRefLazy,

33 + PureComponent,

34 + PureComponentLazy,

35 } from 'shared/ReactWorkTags';

36 import invariant from 'shared/invariant';

37 import ReactVersion from 'shared/ReactVersion';

@@ -199,6 +201,8 @@ function toTree(node: ?Fiber) {

201 case Profiler:

202 case ForwardRef:

203 case ForwardRefLazy:

204 + case PureComponent:

205 + case PureComponentLazy:

206 return childrenToTree(node.child);

207 default:

208 invariant(

@@ -217,6 +221,8 @@ const validWrapperTypes = new Set([

221 HostComponent,

222 ForwardRef,

223 ForwardRefLazy,

224 + PureComponent,

225 + PureComponentLazy,

226 // Normally skipped, but used when there's more than one root child.

227 HostRoot,

228 ]);

packages/react/src/React.js

@@ -27,6 +27,7 @@ import {

27 import {createContext} from './ReactContext';

28 import {lazy} from './ReactLazy';

29 import forwardRef from './forwardRef';

30 +import pure from './pure';

31 import {

32 createElementWithValidation,

33 createFactoryWithValidation,

@@ -49,6 +50,7 @@ const React = {

51 createContext,

52 forwardRef,

53 + pure,

55 Fragment: REACT_FRAGMENT_TYPE,

56 StrictMode: REACT_STRICT_MODE_TYPE,

packages/react/src/pure.js new

+40

@@ -0,0 +1,40 @@

1 +/**

2 + * Copyright (c) Facebook, Inc. and its affiliates.

3 + *

4 + * This source code is licensed under the MIT license found in the

5 + * LICENSE file in the root directory of this source tree.

6 + */

7 +

8 +import {REACT_PURE_TYPE} from 'shared/ReactSymbols';

9 +

10 +import warningWithoutStack from 'shared/warningWithoutStack';

11 +

12 +export default function pure<Props>(

13 + render: (props: Props) => React$Node,

14 + compare?: (oldProps: Props, newProps: Props) => boolean,

15 +) {

16 + if (__DEV__) {

17 + if (typeof render !== 'function') {

18 + warningWithoutStack(

19 + false,

20 + 'pure: The first argument must be a functional component. Instead ' +

21 + 'received: %s',

22 + render === null ? 'null' : typeof render,

23 + );

24 + } else {

25 + const prototype = render.prototype;

26 + if (prototype && prototype.isReactComponent) {

27 + warningWithoutStack(

28 + false,

29 + 'pure: The first argument must be a functional component. Classes ' +

30 + 'are not supported. Use React.PureComponent instead.',

31 + );

32 + }

33 + }

34 + }

35 + return {

36 + $$typeof: REACT_PURE_TYPE,

37 + render,

38 + compare: compare === undefined ? null : compare,

39 + };

40 +}

packages/shared/ReactSymbols.js

@@ -41,6 +41,7 @@ export const REACT_FORWARD_REF_TYPE = hasSymbol

41 export const REACT_PLACEHOLDER_TYPE = hasSymbol

42 ? Symbol.for('react.placeholder')

43 : 0xead1;

44 +export const REACT_PURE_TYPE = hasSymbol ? Symbol.for('react.pure') : 0xead3;

46 const MAYBE_ITERATOR_SYMBOL = typeof Symbol === 'function' && Symbol.iterator;

47 const FAUX_ITERATOR_SYMBOL = '@@iterator';

packages/shared/ReactWorkTags.js

+5 -1

@@ -24,7 +24,9 @@ export type WorkTag =

24 | 13

25 | 14

26 | 15

27 - | 16;

27 + | 16

28 + | 17

29 + | 18;

31 export const FunctionalComponent = 0;

32 export const FunctionalComponentLazy = 1;

@@ -43,3 +45,5 @@ export const ForwardRef = 13;

45 export const ForwardRefLazy = 14;

46 export const Profiler = 15;

47 export const PlaceholderComponent = 16;

48 +export const PureComponent = 17;

49 +export const PureComponentLazy = 18;

packages/shared/isValidElementType.js

@@ -16,6 +16,7 @@ import {

16 REACT_PROVIDER_TYPE,

17 REACT_STRICT_MODE_TYPE,

18 REACT_PLACEHOLDER_TYPE,

19 + REACT_PURE_TYPE,

20 } from 'shared/ReactSymbols';

22 export default function isValidElementType(type: mixed) {

@@ -31,6 +32,7 @@ export default function isValidElementType(type: mixed) {

32 (typeof type === 'object' &&

33 type !== null &&

34 (typeof type.then === 'function' ||

35 + type.$$typeof === REACT_PURE_TYPE ||

36 type.$$typeof === REACT_PROVIDER_TYPE ||

37 type.$$typeof === REACT_CONTEXT_TYPE ||

38 type.$$typeof === REACT_FORWARD_REF_TYPE))