@samitouri / QOS-React-2 / commits / e5a8de81e5

Add compareDocumentPosition to fragment instances (#32722)

This adds `compareDocumentPosition(otherNode)` to fragment instances. The semantics implemented are meant to match typical element positioning, with some fragment specifics. See the unit tests for all expectations. - An element preceding a fragment is `Node.DOCUMENT_POSITION_PRECEDING` - An element after a fragment is `Node.DOCUMENT_POSITION_FOLLOWING` - An element containing the fragment is `Node.DOCUMENT_POSITION_PRECEDING` and `Node.DOCUMENT_POSITION_CONTAINING` - An element within the fragment is `Node.DOCUMENT_POSITION_CONTAINED_BY` - An element compared against an empty fragment will result in `Node.DOCUMENT_POSITION_DISCONNECTED` and `Node.DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC` Since we assume a fragment instances target children are DOM siblings and we want to compare the full fragment as a pseudo container, we can compare against the first target child outside of handling the special cases (empty fragments and contained elements).

Jack Pope committed May 6, 2025 at 13:01 UTC e5a8de81e57181692d33ce916dfd6aa23638ec92

5 files changed +1013 -84

packages/react-dom-bindings/src/client/ReactFiberConfigDOM.js

+171 -24

@@ -37,6 +37,11 @@ import {runWithFiberInDEV} from 'react-reconciler/src/ReactCurrentFiber';

37 import hasOwnProperty from 'shared/hasOwnProperty';

38 import {checkAttributeStringCoercion} from 'shared/CheckStringCoercion';

39 import {REACT_CONTEXT_TYPE} from 'shared/ReactSymbols';

40 +import {

41 + isFiberContainedBy,

42 + isFiberFollowing,

43 + isFiberPreceding,

44 +} from 'react-reconciler/src/ReactFiberTreeReflection';

46 export {

47 setCurrentUpdatePriority,

@@ -60,7 +65,9 @@ import {

65 } from './ReactDOMComponentTree';

66 import {

67 traverseFragmentInstance,

63 - getFragmentParentHostInstance,

68 + getFragmentParentHostFiber,

69 + getNextSiblingHostFiber,

70 + getInstanceFromHostFiber,

71 } from 'react-reconciler/src/ReactFiberTreeReflection';

73 export {detachDeletedInstance};

@@ -2599,6 +2606,7 @@ export type FragmentInstanceType = {

2606 getRootNode(getRootNodeOptions?: {

2607 composed: boolean,

2608 }): Document | ShadowRoot | FragmentInstanceType,

2609 + compareDocumentPosition(otherNode: Instance): number,

2610 };

2611

2612 function FragmentInstance(this: FragmentInstanceType, fragmentFiber: Fiber) {

@@ -2636,12 +2644,13 @@ FragmentInstance.prototype.addEventListener = function (

2644 this._eventListeners = listeners;

2645 };

2646 function addEventListenerToChild(

2639 - child: Instance,

2647 + child: Fiber,

2648 type: string,

2649 listener: EventListener,

2650 optionsOrUseCapture?: EventListenerOptionsOrUseCapture,

2651 ): boolean {

2644 - child.addEventListener(type, listener, optionsOrUseCapture);

2652 + const instance = getInstanceFromHostFiber<Instance>(child);

2653 + instance.addEventListener(type, listener, optionsOrUseCapture);

2654 return false;

2655 }

2656 // $FlowFixMe[prop-missing]

@@ -2675,12 +2684,13 @@ FragmentInstance.prototype.removeEventListener = function (

2684 }

2685 };

2686 function removeEventListenerFromChild(

2678 - child: Instance,

2687 + child: Fiber,

2688 type: string,

2689 listener: EventListener,

2690 optionsOrUseCapture?: EventListenerOptionsOrUseCapture,

2691 ): boolean {

2683 - child.removeEventListener(type, listener, optionsOrUseCapture);

2692 + const instance = getInstanceFromHostFiber<Instance>(child);

2693 + instance.removeEventListener(type, listener, optionsOrUseCapture);

2694 return false;

2695 }

2696 // $FlowFixMe[prop-missing]

@@ -2690,28 +2700,32 @@ FragmentInstance.prototype.focus = function (

2700 ): void {

2701 traverseFragmentInstance(

2702 this._fragmentFiber,

2693 - setFocusIfFocusable,

2703 + setFocusOnFiberIfFocusable,

2704 focusOptions,

2705 );

2706 };

2707 +function setFocusOnFiberIfFocusable(

2708 + fiber: Fiber,

2709 + focusOptions?: FocusOptions,

2710 +): boolean {

2711 + const instance = getInstanceFromHostFiber<Instance>(fiber);

2712 + return setFocusIfFocusable(instance, focusOptions);

2713 +}

2714 // $FlowFixMe[prop-missing]

2715 FragmentInstance.prototype.focusLast = function (

2716 this: FragmentInstanceType,

2717 focusOptions?: FocusOptions,

2718 ): void {

2702 - const children: Array<Instance> = [];

2719 + const children: Array<Fiber> = [];

2720 traverseFragmentInstance(this._fragmentFiber, collectChildren, children);

2721 for (let i = children.length - 1; i >= 0; i--) {

2722 const child = children[i];

2706 - if (setFocusIfFocusable(child, focusOptions)) {

2723 + if (setFocusOnFiberIfFocusable(child, focusOptions)) {

2724 break;

2725 }

2726 }

2727 };

2711 -function collectChildren(

2712 - child: Instance,

2713 - collection: Array<Instance>,

2714 -): boolean {

2728 +function collectChildren(child: Fiber, collection: Array<Fiber>): boolean {

2729 collection.push(child);

2730 return false;

2731 }

@@ -2724,12 +2738,13 @@ FragmentInstance.prototype.blur = function (this: FragmentInstanceType): void {

2738 blurActiveElementWithinFragment,

2739 );

2740 };

2727 -function blurActiveElementWithinFragment(child: Instance): boolean {

2741 +function blurActiveElementWithinFragment(child: Fiber): boolean {

2742 // TODO: We can get the activeElement from the parent outside of the loop when we have a reference.

2729 - const ownerDocument = child.ownerDocument;

2730 - if (child === ownerDocument.activeElement) {

2743 + const instance = getInstanceFromHostFiber<Instance>(child);

2744 + const ownerDocument = instance.ownerDocument;

2745 + if (instance === ownerDocument.activeElement) {

2746 // $FlowFixMe[prop-missing]

2732 - child.blur();

2747 + instance.blur();

2748 return true;

2749 }

2750 return false;

@@ -2746,10 +2761,11 @@ FragmentInstance.prototype.observeUsing = function (

2761 traverseFragmentInstance(this._fragmentFiber, observeChild, observer);

2762 };

2763 function observeChild(

2749 - child: Instance,

2764 + child: Fiber,

2765 observer: IntersectionObserver | ResizeObserver,

2766 ) {

2752 - observer.observe(child);

2767 + const instance = getInstanceFromHostFiber<Instance>(child);

2768 + observer.observe(instance);

2769 return false;

2770 }

2771 // $FlowFixMe[prop-missing]

@@ -2770,10 +2786,11 @@ FragmentInstance.prototype.unobserveUsing = function (

2786 }

2787 };

2788 function unobserveChild(

2773 - child: Instance,

2789 + child: Fiber,

2790 observer: IntersectionObserver | ResizeObserver,

2791 ) {

2776 - observer.unobserve(child);

2792 + const instance = getInstanceFromHostFiber<Instance>(child);

2793 + observer.unobserve(instance);

2794 return false;

2795 }

2796 // $FlowFixMe[prop-missing]

@@ -2784,9 +2801,10 @@ FragmentInstance.prototype.getClientRects = function (

2801 traverseFragmentInstance(this._fragmentFiber, collectClientRects, rects);

2802 return rects;

2803 };

2787 -function collectClientRects(child: Instance, rects: Array<DOMRect>): boolean {

2804 +function collectClientRects(child: Fiber, rects: Array<DOMRect>): boolean {

2805 + const instance = getInstanceFromHostFiber<Instance>(child);

2806 // $FlowFixMe[method-unbinding]

2789 - rects.push.apply(rects, child.getClientRects());

2807 + rects.push.apply(rects, instance.getClientRects());

2808 return false;

2809 }

2810 // $FlowFixMe[prop-missing]

@@ -2794,15 +2812,144 @@ FragmentInstance.prototype.getRootNode = function (

2812 this: FragmentInstanceType,

2813 getRootNodeOptions?: {composed: boolean},

2814 ): Document | ShadowRoot | FragmentInstanceType {

2797 - const parentHostInstance = getFragmentParentHostInstance(this._fragmentFiber);

2798 - if (parentHostInstance === null) {

2815 + const parentHostFiber = getFragmentParentHostFiber(this._fragmentFiber);

2816 + if (parentHostFiber === null) {

2817 return this;

2818 }

2819 + const parentHostInstance =

2820 + getInstanceFromHostFiber<Instance>(parentHostFiber);

2821 const rootNode =

2822 // $FlowFixMe[incompatible-cast] Flow expects Node

2823 (parentHostInstance.getRootNode(getRootNodeOptions): Document | ShadowRoot);

2824 return rootNode;

2825 };

2826 +// $FlowFixMe[prop-missing]

2827 +FragmentInstance.prototype.compareDocumentPosition = function (

2828 + this: FragmentInstanceType,

2829 + otherNode: Instance,

2830 +): number {

2831 + const parentHostFiber = getFragmentParentHostFiber(this._fragmentFiber);

2832 + if (parentHostFiber === null) {

2833 + return Node.DOCUMENT_POSITION_DISCONNECTED;

2834 + }

2835 + const children: Array<Fiber> = [];

2836 + traverseFragmentInstance(this._fragmentFiber, collectChildren, children);

2837 +

2838 + let result = Node.DOCUMENT_POSITION_DISCONNECTED;

2839 + if (children.length === 0) {

2840 + // If the fragment has no children, we can use the parent and

2841 + // siblings to determine a position.

2842 + const parentHostInstance =

2843 + getInstanceFromHostFiber<Instance>(parentHostFiber);

2844 + const parentResult = parentHostInstance.compareDocumentPosition(otherNode);

2845 + result = parentResult;

2846 + if (parentHostInstance === otherNode) {

2847 + result = Node.DOCUMENT_POSITION_CONTAINS;

2848 + } else {

2849 + if (parentResult & Node.DOCUMENT_POSITION_CONTAINED_BY) {

2850 + // otherNode is one of the fragment's siblings. Use the next

2851 + // sibling to determine if its preceding or following.

2852 + const nextSiblingFiber = getNextSiblingHostFiber(this._fragmentFiber);

2853 + if (nextSiblingFiber === null) {

2854 + result = Node.DOCUMENT_POSITION_PRECEDING;

2855 + } else {

2856 + const nextSiblingInstance =

2857 + getInstanceFromHostFiber<Instance>(nextSiblingFiber);

2858 + const nextSiblingResult =

2859 + nextSiblingInstance.compareDocumentPosition(otherNode);

2860 + if (

2861 + nextSiblingResult === 0 ||

2862 + nextSiblingResult & Node.DOCUMENT_POSITION_FOLLOWING

2863 + ) {

2864 + result = Node.DOCUMENT_POSITION_FOLLOWING;

2865 + } else {

2866 + result = Node.DOCUMENT_POSITION_PRECEDING;

2867 + }

2868 + }

2869 + }

2870 + }

2871 +

2872 + result |= Node.DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC;

2873 + return result;

2874 + }

2875 +

2876 + const firstElement = getInstanceFromHostFiber<Instance>(children[0]);

2877 + const lastElement = getInstanceFromHostFiber<Instance>(

2878 + children[children.length - 1],

2879 + );

2880 + const firstResult = firstElement.compareDocumentPosition(otherNode);

2881 + const lastResult = lastElement.compareDocumentPosition(otherNode);

2882 + if (

2883 + (firstResult & Node.DOCUMENT_POSITION_FOLLOWING &&

2884 + lastResult & Node.DOCUMENT_POSITION_PRECEDING) ||

2885 + otherNode === firstElement ||

2886 + otherNode === lastElement

2887 + ) {

2888 + result = Node.DOCUMENT_POSITION_CONTAINED_BY;

2889 + } else {

2890 + result = firstResult;

2891 + }

2892 +

2893 + if (

2894 + result & Node.DOCUMENT_POSITION_DISCONNECTED ||

2895 + result & Node.DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC

2896 + ) {

2897 + return result;

2898 + }

2899 +

2900 + // Now that we have the result from the DOM API, we double check it matches

2901 + // the state of the React tree. If it doesn't, we have a case of portaled or

2902 + // otherwise injected elements and we return DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC.

2903 + const documentPositionMatchesFiberPosition =

2904 + validateDocumentPositionWithFiberTree(

2905 + result,

2906 + this._fragmentFiber,

2907 + children[0],

2908 + children[children.length - 1],

2909 + otherNode,

2910 + );

2911 + if (documentPositionMatchesFiberPosition) {

2912 + return result;

2913 + }

2914 + return Node.DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC;

2915 +};

2916 +

2917 +function validateDocumentPositionWithFiberTree(

2918 + documentPosition: number,

2919 + fragmentFiber: Fiber,

2920 + precedingBoundaryFiber: Fiber,

2921 + followingBoundaryFiber: Fiber,

2922 + otherNode: Instance,

2923 +): boolean {

2924 + const otherFiber = getClosestInstanceFromNode(otherNode);

2925 + if (documentPosition & Node.DOCUMENT_POSITION_CONTAINED_BY) {

2926 + return !!otherFiber && isFiberContainedBy(fragmentFiber, otherFiber);

2927 + }

2928 + if (documentPosition & Node.DOCUMENT_POSITION_CONTAINS) {

2929 + if (otherFiber === null) {

2930 + // otherFiber could be null if its the document or body element

2931 + const ownerDocument = otherNode.ownerDocument;

2932 + return otherNode === ownerDocument || otherNode === ownerDocument.body;

2933 + }

2934 + return isFiberContainedBy(otherFiber, fragmentFiber);

2935 + }

2936 + if (documentPosition & Node.DOCUMENT_POSITION_PRECEDING) {

2937 + return (

2938 + !!otherFiber &&

2939 + (otherFiber === precedingBoundaryFiber ||

2940 + isFiberPreceding(precedingBoundaryFiber, otherFiber))

2941 + );

2942 + }

2943 + if (documentPosition & Node.DOCUMENT_POSITION_FOLLOWING) {

2944 + return (

2945 + !!otherFiber &&

2946 + (otherFiber === followingBoundaryFiber ||

2947 + isFiberFollowing(followingBoundaryFiber, otherFiber))

2948 + );

2949 + }

2950 +

2951 + return false;

2952 +}

2953

2954 function normalizeListenerOptions(

2955 opts: ?EventListenerOptionsOrUseCapture,

packages/react-dom-bindings/src/events/DOMPluginEventSystem.js

+3 -41

@@ -36,6 +36,7 @@ import {

36 HostText,

37 ScopeComponent,

38 } from 'react-reconciler/src/ReactWorkTags';

39 +import {getLowestCommonAncestor} from 'react-reconciler/src/ReactFiberTreeReflection';

41 import getEventTarget from './getEventTarget';

42 import {

@@ -891,46 +892,6 @@ function getParent(inst: Fiber | null): Fiber | null {

892 return null;

893 }

894

894 -/**

895 - * Return the lowest common ancestor of A and B, or null if they are in

896 - * different trees.

897 - */

898 -function getLowestCommonAncestor(instA: Fiber, instB: Fiber): Fiber | null {

899 - let nodeA: null | Fiber = instA;

900 - let nodeB: null | Fiber = instB;

901 - let depthA = 0;

902 - for (let tempA: null | Fiber = nodeA; tempA; tempA = getParent(tempA)) {

903 - depthA++;

904 - }

905 - let depthB = 0;

906 - for (let tempB: null | Fiber = nodeB; tempB; tempB = getParent(tempB)) {

907 - depthB++;

908 - }

909 -

910 - // If A is deeper, crawl up.

911 - while (depthA - depthB > 0) {

912 - nodeA = getParent(nodeA);

913 - depthA--;

914 - }

915 -

916 - // If B is deeper, crawl up.

917 - while (depthB - depthA > 0) {

918 - nodeB = getParent(nodeB);

919 - depthB--;

920 - }

921 -

922 - // Walk in lockstep until we find a match.

923 - let depth = depthA;

924 - while (depth--) {

925 - if (nodeA === nodeB || (nodeB !== null && nodeA === nodeB.alternate)) {

926 - return nodeA;

927 - }

928 - nodeA = getParent(nodeA);

929 - nodeB = getParent(nodeB);

930 - }

931 - return null;

932 -}

933 -

895 function accumulateEnterLeaveListenersForEvent(

896 dispatchQueue: DispatchQueue,

897 event: KnownReactSyntheticEvent,

@@ -992,7 +953,8 @@ export function accumulateEnterLeaveTwoPhaseListeners(

953 from: Fiber | null,

954 to: Fiber | null,

955 ): void {

995 - const common = from && to ? getLowestCommonAncestor(from, to) : null;

956 + const common =

957 + from && to ? getLowestCommonAncestor(from, to, getParent) : null;

958

959 if (from !== null) {

960 accumulateEnterLeaveListenersForEvent(

packages/react-dom/src/__tests__/ReactDOMFragmentRefs-test.js

+602

@@ -11,6 +11,8 @@

12 let React;

13 let ReactDOMClient;

14 +let ReactDOM;

15 +let createPortal;

16 let act;

17 let container;

18 let Fragment;

@@ -31,6 +33,8 @@ describe('FragmentRefs', () => {

33 Fragment = React.Fragment;

34 Activity = React.unstable_Activity;

35 ReactDOMClient = require('react-dom/client');

36 + ReactDOM = require('react-dom');

37 + createPortal = ReactDOM.createPortal;

38 act = require('internal-test-utils').act;

39 const IntersectionMocks = require('./utils/IntersectionMocks');

40 mockIntersectionObserver = IntersectionMocks.mockIntersectionObserver;

@@ -40,6 +44,7 @@ describe('FragmentRefs', () => {

44 require('internal-test-utils').assertConsoleErrorDev;

46 container = document.createElement('div');

47 + document.body.innerHTML = '';

48 document.body.appendChild(container);

49 });

@@ -611,6 +616,39 @@ describe('FragmentRefs', () => {

616 expect(logs).toEqual([]);

617 });

618

619 + // @gate enableFragmentRefs

620 + it('applies event listeners to portaled children', async () => {

621 + const fragmentRef = React.createRef();

622 + const childARef = React.createRef();

623 + const childBRef = React.createRef();

624 + const root = ReactDOMClient.createRoot(container);

625 +

626 + function Test() {

627 + return (

628 + <Fragment ref={fragmentRef}>

629 + <div id="child-a" ref={childARef} />

630 + {createPortal(<div id="child-b" ref={childBRef} />, document.body)}

631 + </Fragment>

632 + );

633 + }

634 +

635 + await act(() => {

636 + root.render(<Test />);

637 + });

638 +

639 + const logs = [];

640 + fragmentRef.current.addEventListener('click', e => {

641 + logs.push(e.target.id);

642 + });

643 +

644 + childARef.current.click();

645 + expect(logs).toEqual(['child-a']);

646 +

647 + logs.length = 0;

648 + childBRef.current.click();

649 + expect(logs).toEqual(['child-b']);

650 + });

651 +

652 describe('with activity', () => {

653 // @gate enableFragmentRefs && enableActivity

654 it('does not apply event listeners to hidden trees', async () => {

@@ -966,4 +1004,568 @@ describe('FragmentRefs', () => {

1004 expect(fragmentHandle.getRootNode()).toBe(fragmentHandle);

1005 });

1006 });

1007 +

1008 + describe('compareDocumentPosition', () => {

1009 + function expectPosition(position, spec) {

1010 + const positionResult = {

1011 + following: (position & Node.DOCUMENT_POSITION_FOLLOWING) !== 0,

1012 + preceding: (position & Node.DOCUMENT_POSITION_PRECEDING) !== 0,

1013 + contains: (position & Node.DOCUMENT_POSITION_CONTAINS) !== 0,

1014 + containedBy: (position & Node.DOCUMENT_POSITION_CONTAINED_BY) !== 0,

1015 + disconnected: (position & Node.DOCUMENT_POSITION_DISCONNECTED) !== 0,

1016 + implementationSpecific:

1017 + (position & Node.DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC) !== 0,

1018 + };

1019 + expect(positionResult).toEqual(spec);

1020 + }

1021 + // @gate enableFragmentRefs

1022 + it('returns the relationship between the fragment instance and a given node', async () => {

1023 + const fragmentRef = React.createRef();

1024 + const beforeRef = React.createRef();

1025 + const afterRef = React.createRef();

1026 + const middleChildRef = React.createRef();

1027 + const firstChildRef = React.createRef();

1028 + const lastChildRef = React.createRef();

1029 + const containerRef = React.createRef();

1030 + const disconnectedElement = document.createElement('div');

1031 + const root = ReactDOMClient.createRoot(container);

1032 +

1033 + function Test() {

1034 + return (

1035 + <div ref={containerRef}>

1036 + <div ref={beforeRef} />

1037 + <React.Fragment ref={fragmentRef}>

1038 + <div ref={firstChildRef} />

1039 + <div ref={middleChildRef} />

1040 + <div ref={lastChildRef} />

1041 + </React.Fragment>

1042 + <div ref={afterRef} />

1043 + </div>

1044 + );

1045 + }

1046 +

1047 + await act(() => root.render(<Test />));

1048 +

1049 + // document.body is preceding and contains the fragment

1050 + expectPosition(

1051 + fragmentRef.current.compareDocumentPosition(document.body),

1052 + {

1053 + preceding: true,

1054 + following: false,

1055 + contains: true,

1056 + containedBy: false,

1057 + disconnected: false,

1058 + implementationSpecific: false,

1059 + },

1060 + );

1061 +

1062 + // beforeRef is preceding the fragment

1063 + expectPosition(

1064 + fragmentRef.current.compareDocumentPosition(beforeRef.current),

1065 + {

1066 + preceding: true,

1067 + following: false,

1068 + contains: false,

1069 + containedBy: false,

1070 + disconnected: false,

1071 + implementationSpecific: false,

1072 + },

1073 + );

1074 +

1075 + // afterRef is following the fragment

1076 + expectPosition(

1077 + fragmentRef.current.compareDocumentPosition(afterRef.current),

1078 + {

1079 + preceding: false,

1080 + following: true,

1081 + contains: false,

1082 + containedBy: false,

1083 + disconnected: false,

1084 + implementationSpecific: false,

1085 + },

1086 + );

1087 +

1088 + // firstChildRef is contained by the fragment

1089 + expectPosition(

1090 + fragmentRef.current.compareDocumentPosition(firstChildRef.current),

1091 + {

1092 + preceding: false,

1093 + following: false,

1094 + contains: false,

1095 + containedBy: true,

1096 + disconnected: false,

1097 + implementationSpecific: false,

1098 + },

1099 + );

1100 +

1101 + // middleChildRef is contained by the fragment

1102 + expectPosition(

1103 + fragmentRef.current.compareDocumentPosition(middleChildRef.current),

1104 + {

1105 + preceding: false,

1106 + following: false,

1107 + contains: false,

1108 + containedBy: true,

1109 + disconnected: false,

1110 + implementationSpecific: false,

1111 + },

1112 + );

1113 +

1114 + // lastChildRef is contained by the fragment

1115 + expectPosition(

1116 + fragmentRef.current.compareDocumentPosition(lastChildRef.current),

1117 + {

1118 + preceding: false,

1119 + following: false,

1120 + contains: false,

1121 + containedBy: true,

1122 + disconnected: false,

1123 + implementationSpecific: false,

1124 + },

1125 + );

1126 +

1127 + // containerRef preceds and contains the fragment

1128 + expectPosition(

1129 + fragmentRef.current.compareDocumentPosition(containerRef.current),

1130 + {

1131 + preceding: true,

1132 + following: false,

1133 + contains: true,

1134 + containedBy: false,

1135 + disconnected: false,

1136 + implementationSpecific: false,

1137 + },

1138 + );

1139 +

1140 + expectPosition(

1141 + fragmentRef.current.compareDocumentPosition(disconnectedElement),

1142 + {

1143 + preceding: false,

1144 + following: true,

1145 + contains: false,

1146 + containedBy: false,

1147 + disconnected: true,

1148 + implementationSpecific: true,

1149 + },

1150 + );

1151 + });

1152 +

1153 + // @gate enableFragmentRefs

1154 + it('handles fragment instances with one child', async () => {

1155 + const fragmentRef = React.createRef();

1156 + const beforeRef = React.createRef();

1157 + const afterRef = React.createRef();

1158 + const containerRef = React.createRef();

1159 + const onlyChildRef = React.createRef();

1160 + const disconnectedElement = document.createElement('div');

1161 + const root = ReactDOMClient.createRoot(container);

1162 +

1163 + function Test() {

1164 + return (

1165 + <div id="container" ref={containerRef}>

1166 + <div>

1167 + <div ref={beforeRef} id="before" />

1168 + <React.Fragment ref={fragmentRef}>

1169 + <div ref={onlyChildRef} id="within" />

1170 + </React.Fragment>

1171 + <div id="after" ref={afterRef} />

1172 + </div>

1173 + </div>

1174 + );

1175 + }

1176 +

1177 + await act(() => root.render(<Test />));

1178 + expectPosition(

1179 + fragmentRef.current.compareDocumentPosition(beforeRef.current),

1180 + {

1181 + preceding: true,

1182 + following: false,

1183 + contains: false,

1184 + containedBy: false,

1185 + disconnected: false,

1186 + implementationSpecific: false,

1187 + },

1188 + );

1189 + expectPosition(

1190 + fragmentRef.current.compareDocumentPosition(afterRef.current),

1191 + {

1192 + preceding: false,

1193 + following: true,

1194 + contains: false,

1195 + containedBy: false,

1196 + disconnected: false,

1197 + implementationSpecific: false,

1198 + },

1199 + );

1200 + expectPosition(

1201 + fragmentRef.current.compareDocumentPosition(onlyChildRef.current),

1202 + {

1203 + preceding: false,

1204 + following: false,

1205 + contains: false,

1206 + containedBy: true,

1207 + disconnected: false,

1208 + implementationSpecific: false,

1209 + },

1210 + );

1211 + expectPosition(

1212 + fragmentRef.current.compareDocumentPosition(containerRef.current),

1213 + {

1214 + preceding: true,

1215 + following: false,

1216 + contains: true,

1217 + containedBy: false,

1218 + disconnected: false,

1219 + implementationSpecific: false,

1220 + },

1221 + );

1222 + expectPosition(

1223 + fragmentRef.current.compareDocumentPosition(disconnectedElement),

1224 + {

1225 + preceding: false,

1226 + following: true,

1227 + contains: false,

1228 + containedBy: false,

1229 + disconnected: true,

1230 + implementationSpecific: true,

1231 + },

1232 + );

1233 + });

1234 +

1235 + // @gate enableFragmentRefs

1236 + it('handles empty fragment instances', async () => {

1237 + const fragmentRef = React.createRef();

1238 + const beforeParentRef = React.createRef();

1239 + const beforeRef = React.createRef();

1240 + const afterRef = React.createRef();

1241 + const afterParentRef = React.createRef();

1242 + const containerRef = React.createRef();

1243 + const root = ReactDOMClient.createRoot(container);

1244 +

1245 + function Test() {

1246 + return (

1247 + <>

1248 + <div id="before-container" ref={beforeParentRef} />

1249 + <div id="container" ref={containerRef}>

1250 + <div id="before" ref={beforeRef} />

1251 + <React.Fragment ref={fragmentRef} />

1252 + <div id="after" ref={afterRef} />

1253 + </div>

1254 + <div id="after-container" ref={afterParentRef} />

1255 + </>

1256 + );

1257 + }

1258 +

1259 + await act(() => root.render(<Test />));

1260 +

1261 + expectPosition(

1262 + fragmentRef.current.compareDocumentPosition(document.body),

1263 + {

1264 + preceding: true,

1265 + following: false,

1266 + contains: true,

1267 + containedBy: false,

1268 + disconnected: false,

1269 + implementationSpecific: true,

1270 + },

1271 + );

1272 + expectPosition(

1273 + fragmentRef.current.compareDocumentPosition(beforeRef.current),

1274 + {

1275 + preceding: true,

1276 + following: false,

1277 + contains: false,

1278 + containedBy: false,

1279 + disconnected: false,

1280 + implementationSpecific: true,

1281 + },

1282 + );

1283 + expectPosition(

1284 + fragmentRef.current.compareDocumentPosition(beforeParentRef.current),

1285 + {

1286 + preceding: true,

1287 + following: false,

1288 + contains: false,

1289 + containedBy: false,

1290 + disconnected: false,

1291 + implementationSpecific: true,

1292 + },

1293 + );

1294 + expectPosition(

1295 + fragmentRef.current.compareDocumentPosition(afterRef.current),

1296 + {

1297 + preceding: false,

1298 + following: true,

1299 + contains: false,

1300 + containedBy: false,

1301 + disconnected: false,

1302 + implementationSpecific: true,

1303 + },

1304 + );

1305 + expectPosition(

1306 + fragmentRef.current.compareDocumentPosition(afterParentRef.current),

1307 + {

1308 + preceding: false,

1309 + following: true,

1310 + contains: false,

1311 + containedBy: false,

1312 + disconnected: false,

1313 + implementationSpecific: true,

1314 + },

1315 + );

1316 + expectPosition(

1317 + fragmentRef.current.compareDocumentPosition(containerRef.current),

1318 + {

1319 + preceding: false,

1320 + following: false,

1321 + contains: true,

1322 + containedBy: false,

1323 + disconnected: false,

1324 + implementationSpecific: true,

1325 + },

1326 + );

1327 + });

1328 +

1329 + // @gate enableFragmentRefs

1330 + it('returns disconnected for comparison with an unmounted fragment instance', async () => {

1331 + const fragmentRef = React.createRef();

1332 + const containerRef = React.createRef();

1333 + const root = ReactDOMClient.createRoot(container);

1334 +

1335 + function Test({mount}) {

1336 + return (

1337 + <div ref={containerRef}>

1338 + {mount && (

1339 + <Fragment ref={fragmentRef}>

1340 + <div />

1341 + </Fragment>

1342 + )}

1343 + </div>

1344 + );

1345 + }

1346 +

1347 + await act(() => root.render(<Test mount={true} />));

1348 +

1349 + const fragmentHandle = fragmentRef.current;

1350 +

1351 + expectPosition(

1352 + fragmentHandle.compareDocumentPosition(containerRef.current),

1353 + {

1354 + preceding: true,

1355 + following: false,

1356 + contains: true,

1357 + containedBy: false,

1358 + disconnected: false,

1359 + implementationSpecific: false,

1360 + },

1361 + );

1362 +

1363 + await act(() => {

1364 + root.render(<Test mount={false} />);

1365 + });

1366 +

1367 + expectPosition(

1368 + fragmentHandle.compareDocumentPosition(containerRef.current),

1369 + {

1370 + preceding: false,

1371 + following: false,

1372 + contains: false,

1373 + containedBy: false,

1374 + disconnected: true,

1375 + implementationSpecific: false,

1376 + },

1377 + );

1378 + });

1379 +

1380 + describe('with portals', () => {

1381 + // @gate enableFragmentRefs

1382 + it('handles portaled elements', async () => {

1383 + const fragmentRef = React.createRef();

1384 + const portaledSiblingRef = React.createRef();

1385 + const portaledChildRef = React.createRef();

1386 +

1387 + function Test() {

1388 + return (

1389 + <div>

1390 + {createPortal(<div ref={portaledSiblingRef} />, document.body)}

1391 + <Fragment ref={fragmentRef}>

1392 + {createPortal(<div ref={portaledChildRef} />, document.body)}

1393 + <div />

1394 + </Fragment>

1395 + </div>

1396 + );

1397 + }

1398 +

1399 + const root = ReactDOMClient.createRoot(container);

1400 + await act(() => root.render(<Test />));

1401 +

1402 + // The sibling is preceding in both the DOM and the React tree

1403 + expectPosition(

1404 + fragmentRef.current.compareDocumentPosition(

1405 + portaledSiblingRef.current,

1406 + ),

1407 + {

1408 + preceding: true,

1409 + following: false,

1410 + contains: false,

1411 + containedBy: false,

1412 + disconnected: false,

1413 + implementationSpecific: false,

1414 + },

1415 + );

1416 +

1417 + // The child is contained by in the React tree but not in the DOM

1418 + expectPosition(

1419 + fragmentRef.current.compareDocumentPosition(portaledChildRef.current),

1420 + {

1421 + preceding: false,

1422 + following: false,

1423 + contains: false,

1424 + containedBy: false,

1425 + disconnected: false,

1426 + implementationSpecific: true,

1427 + },

1428 + );

1429 + });

1430 +

1431 + // @gate enableFragmentRefs

1432 + it('handles multiple portals to the same element', async () => {

1433 + const root = ReactDOMClient.createRoot(container);

1434 + const fragmentRef = React.createRef();

1435 + const childARef = React.createRef();

1436 + const childBRef = React.createRef();

1437 + const childCRef = React.createRef();

1438 +

1439 + function Test() {

1440 + const [c, setC] = React.useState(false);

1441 + React.useEffect(() => {

1442 + setC(true);

1443 + });

1444 +

1445 + return (

1446 + <>

1447 + {createPortal(

1448 + <Fragment ref={fragmentRef}>

1449 + <div id="A" ref={childARef} />

1450 + {c ? <div id="C" ref={childCRef} /> : null}

1451 + </Fragment>,

1452 + document.body,

1453 + )}

1454 + {createPortal(<p id="B" ref={childBRef} />, document.body)}

1455 + </>

1456 + );

1457 + }

1458 +

1459 + await act(() => root.render(<Test />));

1460 +

1461 + // Due to effect, order is A->B->C

1462 + expect(document.body.innerHTML).toBe(

1463 + '<div></div>' +

1464 + '<div id="A"></div>' +

1465 + '<p id="B"></p>' +

1466 + '<div id="C"></div>',

1467 + );

1468 +

1469 + expectPosition(

1470 + fragmentRef.current.compareDocumentPosition(document.body),

1471 + {

1472 + preceding: true,

1473 + following: false,

1474 + contains: true,

1475 + containedBy: false,

1476 + disconnected: false,

1477 + implementationSpecific: false,

1478 + },

1479 + );

1480 +

1481 + expectPosition(

1482 + fragmentRef.current.compareDocumentPosition(childARef.current),

1483 + {

1484 + preceding: false,

1485 + following: false,

1486 + contains: false,

1487 + containedBy: true,

1488 + disconnected: false,

1489 + implementationSpecific: false,

1490 + },

1491 + );

1492 + expectPosition(

1493 + fragmentRef.current.compareDocumentPosition(childBRef.current),

1494 + {

1495 + preceding: false,

1496 + following: false,

1497 + contains: false,

1498 + containedBy: false,

1499 + disconnected: false,

1500 + implementationSpecific: true,

1501 + },

1502 + );

1503 + expectPosition(

1504 + fragmentRef.current.compareDocumentPosition(childCRef.current),

1505 + {

1506 + preceding: false,

1507 + following: false,

1508 + contains: false,

1509 + containedBy: true,

1510 + disconnected: false,

1511 + implementationSpecific: false,

1512 + },

1513 + );

1514 + });

1515 +

1516 + // @gate enableFragmentRefs

1517 + it('handles empty fragments', async () => {

1518 + const fragmentRef = React.createRef();

1519 + const childARef = React.createRef();

1520 + const childBRef = React.createRef();

1521 +

1522 + function Test() {

1523 + return (

1524 + <>

1525 + <div id="A" ref={childARef} />

1526 + {createPortal(<Fragment ref={fragmentRef} />, document.body)}

1527 + <div id="B" ref={childBRef} />

1528 + </>

1529 + );

1530 + }

1531 +

1532 + const root = ReactDOMClient.createRoot(container);

1533 + await act(() => root.render(<Test />));

1534 +

1535 + expectPosition(

1536 + fragmentRef.current.compareDocumentPosition(document.body),

1537 + {

1538 + preceding: true,

1539 + following: false,

1540 + contains: true,

1541 + containedBy: false,

1542 + disconnected: false,

1543 + implementationSpecific: true,

1544 + },

1545 + );

1546 + expectPosition(

1547 + fragmentRef.current.compareDocumentPosition(childARef.current),

1548 + {

1549 + preceding: true,

1550 + following: false,

1551 + contains: false,

1552 + containedBy: false,

1553 + disconnected: false,

1554 + implementationSpecific: true,

1555 + },

1556 + );

1557 + expectPosition(

1558 + fragmentRef.current.compareDocumentPosition(childBRef.current),

1559 + {

1560 + preceding: true,

1561 + following: false,

1562 + contains: false,

1563 + containedBy: false,

1564 + disconnected: false,

1565 + implementationSpecific: true,

1566 + },

1567 + );

1568 + });

1569 + });

1570 + });

1571 });

packages/react-native-renderer/src/ReactFiberConfigFabric.js

+9 -4

@@ -24,7 +24,10 @@ import {

24 } from 'react-reconciler/src/ReactEventPriorities';

25 import type {Fiber} from 'react-reconciler/src/ReactInternalTypes';

26 import {HostText} from 'react-reconciler/src/ReactWorkTags';

27 -import {traverseFragmentInstance} from 'react-reconciler/src/ReactFiberTreeReflection';

27 +import {

28 + getInstanceFromHostFiber,

29 + traverseFragmentInstance,

30 +} from 'react-reconciler/src/ReactFiberTreeReflection';

32 // Modules provided by RN:

33 import {

@@ -640,7 +643,8 @@ FragmentInstance.prototype.observeUsing = function (

643 this._observers.add(observer);

644 traverseFragmentInstance(this._fragmentFiber, observeChild, observer);

645 };

643 -function observeChild(instance: Instance, observer: IntersectionObserver) {

646 +function observeChild(child: Fiber, observer: IntersectionObserver) {

647 + const instance = getInstanceFromHostFiber<Instance>(child);

648 const publicInstance = getPublicInstance(instance);

649 if (publicInstance == null) {

650 throw new Error('Expected to find a host node. This is a bug in React.');

@@ -666,7 +670,8 @@ FragmentInstance.prototype.unobserveUsing = function (

670 traverseFragmentInstance(this._fragmentFiber, unobserveChild, observer);

671 }

672 };

669 -function unobserveChild(instance: Instance, observer: IntersectionObserver) {

673 +function unobserveChild(child: Fiber, observer: IntersectionObserver) {

674 + const instance = getInstanceFromHostFiber<Instance>(child);

675 const publicInstance = getPublicInstance(instance);

676 if (publicInstance == null) {

677 throw new Error('Expected to find a host node. This is a bug in React.');

@@ -690,7 +695,7 @@ export function updateFragmentInstanceFiber(

695 }

696

697 export function commitNewChildToFragmentInstance(

693 - child: Instance,

698 + child: Fiber,

699 fragmentInstance: FragmentInstanceType,

700 ): void {

701 if (fragmentInstance._observers !== null) {

packages/react-reconciler/src/ReactFiberTreeReflection.js

+228 -15

@@ -12,7 +12,6 @@ import type {

12 Container,

13 ActivityInstance,

14 SuspenseInstance,

15 - Instance,

15 } from './ReactFiberConfig';

16 import type {ActivityState} from './ReactFiberActivityComponent';

17 import type {SuspenseState} from './ReactFiberSuspenseComponent';

@@ -345,27 +344,42 @@ export function doesFiberContain(

344 return false;

345 }

346

348 -export function traverseFragmentInstance<I, A, B, C>(

347 +export function traverseFragmentInstance<A, B, C>(

348 fragmentFiber: Fiber,

350 - fn: (I, A, B, C) => boolean,

349 + fn: (Fiber, A, B, C) => boolean,

350 a: A,

351 b: B,

352 c: C,

353 ): void {

355 - traverseFragmentInstanceChildren(fragmentFiber.child, fn, a, b, c);

354 + traverseVisibleHostChildren(fragmentFiber.child, false, fn, a, b, c);

355 }

356

358 -function traverseFragmentInstanceChildren<I, A, B, C>(

357 +function traverseVisibleHostChildren<A, B, C>(

358 child: Fiber | null,

360 - fn: (I, A, B, C) => boolean,

359 + searchWithinHosts: boolean,

360 + fn: (Fiber, A, B, C) => boolean,

361 a: A,

362 b: B,

363 c: C,

364 -): void {

364 +): boolean {

365 while (child !== null) {

366 if (child.tag === HostComponent) {

367 - if (fn(child.stateNode, a, b, c)) {

368 - return;

367 + if (fn(child, a, b, c)) {

368 + return true;

369 + }

370 + if (searchWithinHosts) {

371 + if (

372 + traverseVisibleHostChildren(

373 + child.child,

374 + searchWithinHosts,

375 + fn,

376 + a,

377 + b,

378 + c,

379 + )

380 + ) {

381 + return true;

382 + }

383 }

384 } else if (

385 child.tag === OffscreenComponent &&

@@ -373,23 +387,222 @@ function traverseFragmentInstanceChildren<I, A, B, C>(

387 ) {

388 // Skip hidden subtrees

389 } else {

376 - traverseFragmentInstanceChildren(child.child, fn, a, b, c);

390 + if (

391 + traverseVisibleHostChildren(child.child, searchWithinHosts, fn, a, b, c)

392 + ) {

393 + return true;

394 + }

395 }

396 child = child.sibling;

397 }

398 + return false;

399 }

400

382 -export function getFragmentParentHostInstance(fiber: Fiber): null | Instance {

401 +export function getFragmentParentHostFiber(fiber: Fiber): null | Fiber {

402 let parent = fiber.return;

403 while (parent !== null) {

385 - if (parent.tag === HostRoot) {

386 - return parent.stateNode.containerInfo;

404 + if (parent.tag === HostRoot || parent.tag === HostComponent) {

405 + return parent;

406 }

388 - if (parent.tag === HostComponent) {

389 - return parent.stateNode;

407 + parent = parent.return;

408 + }

409 +

410 + return null;

411 +}

412 +

413 +export function getInstanceFromHostFiber<I>(fiber: Fiber): I {

414 + switch (fiber.tag) {

415 + case HostComponent:

416 + return fiber.stateNode;

417 + case HostRoot:

418 + return fiber.stateNode.containerInfo;

419 + default:

420 + throw new Error('Expected to find a host node. This is a bug in React.');

421 + }

422 +}

423 +

424 +let searchTarget = null;

425 +let searchBoundary = null;

426 +function pushSearchTarget(target: null | Fiber): void {

427 + searchTarget = target;

428 +}

429 +function popSearchTarget(): null | Fiber {

430 + return searchTarget;

431 +}

432 +function pushSearchBoundary(value: null | Fiber): void {

433 + searchBoundary = value;

434 +}

435 +function popSearchBoundary(): null | Fiber {

436 + return searchBoundary;

437 +}

438 +

439 +export function getNextSiblingHostFiber(fiber: Fiber): null | Fiber {

440 + traverseVisibleHostChildren(fiber.sibling, false, findNextSibling);

441 + const sibling = popSearchTarget();

442 + pushSearchTarget(null);

443 + return sibling;

444 +}

445 +

446 +function findNextSibling(child: Fiber): boolean {

447 + pushSearchTarget(child);

448 + return true;

449 +}

450 +

451 +export function isFiberContainedBy(

452 + maybeChild: Fiber,

453 + maybeParent: Fiber,

454 +): boolean {

455 + let parent = maybeParent.return;

456 + if (parent === maybeChild || parent === maybeChild.alternate) {

457 + return true;

458 + }

459 + while (parent !== null && parent !== maybeChild) {

460 + if (

461 + (parent.tag === HostComponent || parent.tag === HostRoot) &&

462 + (parent.return === maybeChild || parent.return === maybeChild.alternate)

463 + ) {

464 + return true;

465 }

466 parent = parent.return;

467 }

468 + return false;

469 +}

470 +

471 +export function isFiberPreceding(fiber: Fiber, otherFiber: Fiber): boolean {

472 + const commonAncestor = getLowestCommonAncestor(

473 + fiber,

474 + otherFiber,

475 + getParentForFragmentAncestors,

476 + );

477 + if (commonAncestor === null) {

478 + return false;

479 + }

480 + traverseVisibleHostChildren(

481 + commonAncestor,

482 + true,

483 + isFiberPrecedingCheck,

484 + otherFiber,

485 + fiber,

486 + );

487 + const target = popSearchTarget();

488 + pushSearchTarget(null);

489 + return target !== null;

490 +}

491 +

492 +function isFiberPrecedingCheck(

493 + child: Fiber,

494 + target: Fiber,

495 + boundary: Fiber,

496 +): boolean {

497 + if (child === boundary) {

498 + return true;

499 + }

500 + if (child === target) {

501 + pushSearchTarget(child);

502 + return true;

503 + }

504 + return false;

505 +}

506 +

507 +export function isFiberFollowing(fiber: Fiber, otherFiber: Fiber): boolean {

508 + const commonAncestor = getLowestCommonAncestor(

509 + fiber,

510 + otherFiber,

511 + getParentForFragmentAncestors,

512 + );

513 + if (commonAncestor === null) {

514 + return false;

515 + }

516 + traverseVisibleHostChildren(

517 + commonAncestor,

518 + true,

519 + isFiberFollowingCheck,

520 + otherFiber,

521 + fiber,

522 + );

523 + const target = popSearchTarget();

524 + pushSearchTarget(null);

525 + pushSearchBoundary(null);

526 + return target !== null;

527 +}

528 +

529 +function isFiberFollowingCheck(

530 + child: Fiber,

531 + target: Fiber,

532 + boundary: Fiber,

533 +): boolean {

534 + if (child === boundary) {

535 + pushSearchBoundary(child);

536 + return false;

537 + }

538 + if (child === target) {

539 + // The target is only following if we already found the boundary.

540 + if (popSearchBoundary() !== null) {

541 + pushSearchTarget(child);

542 + }

543 + return true;

544 + }

545 + return false;

546 +}

547

548 +function getParentForFragmentAncestors(inst: Fiber | null): Fiber | null {

549 + if (inst === null) {

550 + return null;

551 + }

552 + do {

553 + inst = inst === null ? null : inst.return;

554 + } while (

555 + inst &&

556 + inst.tag !== HostComponent &&

557 + inst.tag !== HostSingleton &&

558 + inst.tag !== HostRoot

559 + );

560 + if (inst) {

561 + return inst;

562 + }

563 + return null;

564 +}

565 +

566 +/**

567 + * Return the lowest common ancestor of A and B, or null if they are in

568 + * different trees.

569 + */

570 +export function getLowestCommonAncestor(

571 + instA: Fiber,

572 + instB: Fiber,

573 + getParent: (inst: Fiber | null) => Fiber | null,

574 +): Fiber | null {

575 + let nodeA: null | Fiber = instA;

576 + let nodeB: null | Fiber = instB;

577 + let depthA = 0;

578 + for (let tempA: null | Fiber = nodeA; tempA; tempA = getParent(tempA)) {

579 + depthA++;

580 + }

581 + let depthB = 0;

582 + for (let tempB: null | Fiber = nodeB; tempB; tempB = getParent(tempB)) {

583 + depthB++;

584 + }

585 +

586 + // If A is deeper, crawl up.

587 + while (depthA - depthB > 0) {

588 + nodeA = getParent(nodeA);

589 + depthA--;

590 + }

591 +

592 + // If B is deeper, crawl up.

593 + while (depthB - depthA > 0) {

594 + nodeB = getParent(nodeB);

595 + depthB--;

596 + }

597 +

598 + // Walk in lockstep until we find a match.

599 + let depth = depthA;

600 + while (depth--) {

601 + if (nodeA === nodeB || (nodeB !== null && nodeA === nodeB.alternate)) {

602 + return nodeA;

603 + }

604 + nodeA = getParent(nodeA);

605 + nodeB = getParent(nodeB);

606 + }

607 return null;

608 }