Remove _owner field from JSX elements in prod if string refs are disa…

…bled (#28739) In prod, the `_owner` field is only used for string refs so if we have string refs disabled, we don't need this field. In fact, that's one of the big benefits of deprecating them.
facebook · Apr 11, 2024 · e677333 · e677333
1 parent c0b5d43
commit e677333
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diff --git a/packages/jest-react/src/JestReact.js b/packages/jest-react/src/JestReact.js
@@ -6,7 +6,7 @@
  */
 
 import {REACT_ELEMENT_TYPE, REACT_FRAGMENT_TYPE} from 'shared/ReactSymbols';
-import {enableRefAsProp} from 'shared/ReactFeatureFlags';
+import {disableStringRefs, enableRefAsProp} from 'shared/ReactFeatureFlags';
 
 import isArray from 'shared/isArray';
 
@@ -54,6 +54,14 @@ function createJSXElementForTestComparison(type, props) {
       value: null,
     });
     return element;
+  } else if (!__DEV__ && disableStringRefs) {
+    return {
+      $$typeof: REACT_ELEMENT_TYPE,
+      type: type,
+      key: null,
+      ref: null,
+      props: props,
+    };
   } else {
     return {
       $$typeof: REACT_ELEMENT_TYPE,

diff --git a/packages/react-client/src/ReactFlightClient.js b/packages/react-client/src/ReactFlightClient.js
@@ -38,6 +38,7 @@ import type {Postpone} from 'react/src/ReactPostpone';
 import type {TemporaryReferenceSet} from './ReactFlightTemporaryReferences';
 
 import {
+  disableStringRefs,
   enableBinaryFlight,
   enablePostpone,
   enableRefAsProp,
@@ -498,6 +499,16 @@ function createElement(
       enumerable: false,
       get: nullRefGetter,
     });
+  } else if (!__DEV__ && disableStringRefs) {
+    element = ({
+      // This tag allows us to uniquely identify this as a React Element
+      $$typeof: REACT_ELEMENT_TYPE,
+
+      type,
+      key,
+      ref: null,
+      props,
+    }: any);
   } else {
     element = ({
       // This tag allows us to uniquely identify this as a React Element

diff --git a/packages/react-noop-renderer/src/createReactNoop.js b/packages/react-noop-renderer/src/createReactNoop.js
@@ -32,7 +32,11 @@ import {
   ConcurrentRoot,
   LegacyRoot,
 } from 'react-reconciler/constants';
-import {enableRefAsProp, disableLegacyMode} from 'shared/ReactFeatureFlags';
+import {
+  enableRefAsProp,
+  disableLegacyMode,
+  disableStringRefs,
+} from 'shared/ReactFeatureFlags';
 
 type Container = {
   rootID: string,
@@ -799,6 +803,14 @@ function createReactNoop(reconciler: Function, useMutation: boolean) {
         value: null,
       });
       return element;
+    } else if (!__DEV__ && disableStringRefs) {
+      return {
+        $$typeof: REACT_ELEMENT_TYPE,
+        type: type,
+        key: null,
+        ref: null,
+        props: props,
+      };
     } else {
       return {
         $$typeof: REACT_ELEMENT_TYPE,

diff --git a/packages/react/src/__tests__/ReactCreateElement-test.js b/packages/react/src/__tests__/ReactCreateElement-test.js
@@ -275,7 +275,11 @@ describe('ReactCreateElement', () => {
     }
     const root = ReactDOMClient.createRoot(document.createElement('div'));
     await act(() => root.render(React.createElement(Wrapper)));
-    expect(element._owner.stateNode).toBe(instance);
+    if (__DEV__ || !gate(flags => flags.disableStringRefs)) {
+      expect(element._owner.stateNode).toBe(instance);
+    } else {
+      expect('_owner' in element).toBe(false);
+    }
   });
 
   it('merges an additional argument onto the children prop', () => {

diff --git a/packages/react/src/jsx/ReactJSXElement.js b/packages/react/src/jsx/ReactJSXElement.js
@@ -239,6 +239,19 @@ function ReactElement(type, key, _ref, self, source, owner, props) {
         value: null,
       });
     }
+  } else if (!__DEV__ && disableStringRefs) {
+    // In prod, `ref` is a regular property and _owner doesn't exist.
+    element = {
+      // This tag allows us to uniquely identify this as a React Element
+      $$typeof: REACT_ELEMENT_TYPE,
+
+      // Built-in properties that belong on the element
+      type,
+      key,
+      ref,
+
+      props,
+    };
   } else {
     // In prod, `ref` is a regular property. It will be removed in a
     // future release.
@@ -774,7 +787,7 @@ export function cloneAndReplaceKey(oldElement, newKey) {
     enableRefAsProp ? null : oldElement.ref,
     undefined,
     undefined,
-    oldElement._owner,
+    !__DEV__ && disableStringRefs ? undefined : oldElement._owner,
     oldElement.props,
   );
 }
@@ -800,7 +813,7 @@ export function cloneElement(element, config, children) {
   let ref = enableRefAsProp ? null : element.ref;
 
   // Owner will be preserved, unless ref is overridden
-  let owner = element._owner;
+  let owner = !__DEV__ && disableStringRefs ? undefined : element._owner;
 
   if (config != null) {
     if (hasValidRef(config)) {

diff --git a/packages/shared/ReactElementType.js b/packages/shared/ReactElementType.js
@@ -13,7 +13,7 @@ export type ReactElement = {
   key: any,
   ref: any,
   props: any,
-  // ReactFiber
+  // __DEV__ or for string refs
   _owner: any,
 
   // __DEV__