From 03353401a122274bd4a57f1b5bbde08607650981 Mon Sep 17 00:00:00 2001
From: Jan Kassens <jkassens@meta.com>
Date: Wed, 6 Nov 2024 13:30:33 -0500
Subject: [PATCH] [string-refs] cleanup string ref code

---
 packages/jest-react/src/JestReact.js          |  11 -
 .../react-client/src/ReactFlightClient.js     |  14 -
 .../src/__tests__/ReactFlight-test.js         |   4 +-
 .../src/__tests__/ReactComponent-test.js      | 112 -------
 .../__tests__/ReactCompositeComponent-test.js |   7 +-
 .../ReactDOMServerIntegrationRefs-test.js     |  38 +--
 .../ReactDeprecationWarnings-test.js          | 117 -------
 .../__tests__/ReactFunctionComponent-test.js  |  18 --
 .../multiple-copies-of-react-test.js          |  38 ---
 packages/react-dom/src/__tests__/refs-test.js | 301 ------------------
 .../src/createReactNoop.js                    |  12 +-
 .../src/ReactFiberAsyncDispatcher.js          |   4 +-
 .../src/ReactFiberBeginWork.js                |  22 +-
 .../src/ReactFiberCommitEffects.js            |   3 +-
 .../src/ReactFiberWorkLoop.js                 |  15 +-
 .../src/ReactInternalTypes.js                 |   2 +-
 .../src/__tests__/ReactFiberRefs-test.js      |  29 --
 .../ReactIncrementalSideEffects-test.js       |  34 --
 .../src/__tests__/ReactFlightDOMEdge-test.js  |   4 +-
 .../src/ReactFizzAsyncDispatcher.js           |   6 -
 packages/react-server/src/ReactFizzServer.js  |   3 +-
 .../src/flight/ReactFlightAsyncDispatcher.js  |  10 -
 .../ReactCoffeeScriptClass-test.coffee        |  21 --
 .../src/__tests__/ReactCreateElement-test.js  |   2 +-
 .../react/src/__tests__/ReactES6Class-test.js |  21 --
 .../src/__tests__/ReactElementClone-test.js   |  68 +---
 .../src/__tests__/ReactStrictMode-test.js     |  49 ---
 .../__tests__/ReactTypeScriptClass-test.ts    |  16 -
 packages/react/src/jsx/ReactJSXElement.js     | 205 +-----------
 packages/shared/ReactFeatureFlags.js          |   2 -
 .../forks/ReactFeatureFlags.native-fb.js      |   1 -
 .../forks/ReactFeatureFlags.native-oss.js     |   1 -
 .../forks/ReactFeatureFlags.test-renderer.js  |   1 -
 ...actFeatureFlags.test-renderer.native-fb.js |   1 -
 .../ReactFeatureFlags.test-renderer.www.js    |   2 -
 .../shared/forks/ReactFeatureFlags.www.js     |   1 -
 36 files changed, 35 insertions(+), 1160 deletions(-)
 delete mode 100644 packages/react-dom/src/__tests__/multiple-copies-of-react-test.js

diff --git a/packages/jest-react/src/JestReact.js b/packages/jest-react/src/JestReact.js
index 8fcec97f63f7..3cb9ab88f32f 100644
--- a/packages/jest-react/src/JestReact.js
+++ b/packages/jest-react/src/JestReact.js
@@ -6,7 +6,6 @@
  */
 
 import {REACT_ELEMENT_TYPE, REACT_FRAGMENT_TYPE} from 'shared/ReactSymbols';
-import {disableStringRefs} from 'shared/ReactFeatureFlags';
 const {assertConsoleLogsCleared} = require('internal-test-utils/consoleMock');
 
 import isArray from 'shared/isArray';
@@ -56,14 +55,6 @@ 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,
@@ -71,8 +62,6 @@ function createJSXElementForTestComparison(type, props) {
       key: null,
       ref: null,
       props: props,
-      _owner: null,
-      _store: __DEV__ ? {} : undefined,
     };
   }
 }
diff --git a/packages/react-client/src/ReactFlightClient.js b/packages/react-client/src/ReactFlightClient.js
index 6c370bd2ef65..9a3d3e019867 100644
--- a/packages/react-client/src/ReactFlightClient.js
+++ b/packages/react-client/src/ReactFlightClient.js
@@ -41,7 +41,6 @@ import type {Postpone} from 'react/src/ReactPostpone';
 import type {TemporaryReferenceSet} from './ReactFlightTemporaryReferences';
 
 import {
-  disableStringRefs,
   enableBinaryFlight,
   enablePostpone,
   enableFlightReadableStream,
@@ -688,16 +687,6 @@ 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
@@ -707,9 +696,6 @@ function createElement(
       key,
       ref: null,
       props,
-
-      // Record the component responsible for creating this element.
-      _owner: __DEV__ && owner === null ? response._debugRootOwner : owner,
     }: any);
   }
 
diff --git a/packages/react-client/src/__tests__/ReactFlight-test.js b/packages/react-client/src/__tests__/ReactFlight-test.js
index 47c6db808f04..dc33d03f9426 100644
--- a/packages/react-client/src/__tests__/ReactFlight-test.js
+++ b/packages/react-client/src/__tests__/ReactFlight-test.js
@@ -3268,9 +3268,7 @@ describe('ReactFlight', () => {
         expect(greeting._owner).toBe(greeting._debugInfo[0]);
       } else {
         expect(greeting._debugInfo).toBe(undefined);
-        expect(greeting._owner).toBe(
-          gate(flags => flags.disableStringRefs) ? undefined : null,
-        );
+        expect(greeting._owner).toBe(undefined);
       }
       ReactNoop.render(greeting);
     });
diff --git a/packages/react-dom/src/__tests__/ReactComponent-test.js b/packages/react-dom/src/__tests__/ReactComponent-test.js
index 9b2f443a7c34..645911469754 100644
--- a/packages/react-dom/src/__tests__/ReactComponent-test.js
+++ b/packages/react-dom/src/__tests__/ReactComponent-test.js
@@ -42,19 +42,6 @@ describe('ReactComponent', () => {
     }).toThrowError(/Target container is not a DOM element./);
   });
 
-  // @gate !disableStringRefs
-  it('should throw when supplying a string ref outside of render method', async () => {
-    const container = document.createElement('div');
-    const root = ReactDOMClient.createRoot(container);
-    await expect(
-      act(() => {
-        root.render(<div ref="badDiv" />);
-      }),
-      // TODO: This throws an AggregateError. Need to update test infra to
-      // support matching against AggregateError.
-    ).rejects.toThrow();
-  });
-
   it('should throw (in dev) when children are mutated during render', async () => {
     function Wrapper(props) {
       props.children[1] = <p key={1} />; // Mutation is illegal
@@ -132,105 +119,6 @@ describe('ReactComponent', () => {
     }
   });
 
-  // @gate !disableStringRefs
-  it('string refs do not detach and reattach on every render', async () => {
-    let refVal;
-    class Child extends React.Component {
-      componentDidUpdate() {
-        // The parent ref should still be attached because it hasn't changed
-        // since the last render. If the ref had changed, then this would be
-        // undefined because refs are attached during the same phase (layout)
-        // as componentDidUpdate, in child -> parent order. So the new parent
-        // ref wouldn't have attached yet.
-        refVal = this.props.contextRef();
-      }
-
-      render() {
-        if (this.props.show) {
-          return <div>child</div>;
-        }
-      }
-    }
-
-    class Parent extends React.Component {
-      render() {
-        return (
-          <div id="test-root" ref="root">
-            <Child
-              contextRef={() => this.refs.root}
-              show={this.props.showChild}
-            />
-          </div>
-        );
-      }
-    }
-
-    const container = document.createElement('div');
-    const root = ReactDOMClient.createRoot(container);
-
-    await act(() => {
-      root.render(<Parent />);
-    });
-
-    assertConsoleErrorDev(['contains the string ref']);
-
-    expect(refVal).toBe(undefined);
-    await act(() => {
-      root.render(<Parent showChild={true} />);
-    });
-    expect(refVal).toBe(container.querySelector('#test-root'));
-  });
-
-  // @gate !disableStringRefs
-  it('should support string refs on owned components', async () => {
-    const innerObj = {};
-    const outerObj = {};
-
-    class Wrapper extends React.Component {
-      getObject = () => {
-        return this.props.object;
-      };
-
-      render() {
-        return <div>{this.props.children}</div>;
-      }
-    }
-
-    class Component extends React.Component {
-      render() {
-        const inner = <Wrapper object={innerObj} ref="inner" />;
-        const outer = (
-          <Wrapper object={outerObj} ref="outer">
-            {inner}
-          </Wrapper>
-        );
-        return outer;
-      }
-
-      componentDidMount() {
-        expect(this.refs.inner.getObject()).toEqual(innerObj);
-        expect(this.refs.outer.getObject()).toEqual(outerObj);
-      }
-    }
-
-    const container = document.createElement('div');
-    const root = ReactDOMClient.createRoot(container);
-    await expect(async () => {
-      await act(() => {
-        root.render(<Component />);
-      });
-    }).toErrorDev([
-      'Component "Component" contains the string ref "inner". ' +
-        'Support for string refs will be removed in a future major release. ' +
-        'We recommend using useRef() or createRef() instead. ' +
-        'Learn more about using refs safely here: https://react.dev/link/strict-mode-string-ref\n' +
-        '    in Wrapper (at **)\n' +
-        '    in div (at **)\n' +
-        '    in Wrapper (at **)\n' +
-        '    in Component (at **)',
-    ]);
-  });
-
   it('should not have string refs on unmounted components', async () => {
     class Parent extends React.Component {
       render() {
diff --git a/packages/react-dom/src/__tests__/ReactCompositeComponent-test.js b/packages/react-dom/src/__tests__/ReactCompositeComponent-test.js
index 89d0b83abc3b..444407668120 100644
--- a/packages/react-dom/src/__tests__/ReactCompositeComponent-test.js
+++ b/packages/react-dom/src/__tests__/ReactCompositeComponent-test.js
@@ -537,11 +537,8 @@ describe('ReactCompositeComponent', () => {
   });
 
   it('should cleanup even if render() fatals', async () => {
-    const dispatcherEnabled =
-      __DEV__ ||
-      !gate(flags => flags.disableStringRefs) ||
-      gate(flags => flags.enableCache);
-    const ownerEnabled = __DEV__ || !gate(flags => flags.disableStringRefs);
+    const dispatcherEnabled = __DEV__ || gate(flags => flags.enableCache);
+    const ownerEnabled = __DEV__;
 
     let stashedDispatcher;
     class BadComponent extends React.Component {
diff --git a/packages/react-dom/src/__tests__/ReactDOMServerIntegrationRefs-test.js b/packages/react-dom/src/__tests__/ReactDOMServerIntegrationRefs-test.js
index b8d1a0716ae5..9094af348472 100644
--- a/packages/react-dom/src/__tests__/ReactDOMServerIntegrationRefs-test.js
+++ b/packages/react-dom/src/__tests__/ReactDOMServerIntegrationRefs-test.js
@@ -29,12 +29,8 @@ function initModules() {
   };
 }
 
-const {
-  resetModules,
-  asyncReactDOMRender,
-  clientRenderOnServerString,
-  expectMarkupMatch,
-} = ReactDOMServerIntegrationUtils(initModules);
+const {resetModules, clientRenderOnServerString, expectMarkupMatch} =
+  ReactDOMServerIntegrationUtils(initModules);
 
 describe('ReactDOMServerIntegration', () => {
   beforeEach(() => {
@@ -75,36 +71,6 @@ describe('ReactDOMServerIntegration', () => {
       expect(refElement).not.toBe(null);
       expect(refElement).toBe(e);
     });
-
-    // @gate !disableStringRefs
-    it('should have string refs on client when rendered over server markup', async () => {
-      class RefsComponent extends React.Component {
-        render() {
-          return <div ref="myDiv" />;
-        }
-      }
-
-      const markup = ReactDOMServer.renderToString(<RefsComponent />);
-      const root = document.createElement('div');
-      root.innerHTML = markup;
-      let component = null;
-      resetModules();
-      await expect(async () => {
-        await asyncReactDOMRender(
-          <RefsComponent ref={e => (component = e)} />,
-          root,
-          true,
-        );
-      }).toErrorDev([
-        'Component "RefsComponent" contains the string ref "myDiv". ' +
-          'Support for string refs will be removed in a future major release. ' +
-          'We recommend using useRef() or createRef() instead. ' +
-          'Learn more about using refs safely here: https://react.dev/link/strict-mode-string-ref\n' +
-          '    in div (at **)\n' +
-          '    in RefsComponent (at **)',
-      ]);
-      expect(component.refs.myDiv).toBe(root.firstChild);
-    });
   });
 
   it('should forward refs', async () => {
diff --git a/packages/react-dom/src/__tests__/ReactDeprecationWarnings-test.js b/packages/react-dom/src/__tests__/ReactDeprecationWarnings-test.js
index 77c9e1886e0a..e0022dd99004 100644
--- a/packages/react-dom/src/__tests__/ReactDeprecationWarnings-test.js
+++ b/packages/react-dom/src/__tests__/ReactDeprecationWarnings-test.js
@@ -11,7 +11,6 @@
 
 let React;
 let ReactNoop;
-let JSXDEVRuntime;
 let waitForAll;
 
 describe('ReactDeprecationWarnings', () => {
@@ -21,9 +20,6 @@ describe('ReactDeprecationWarnings', () => {
     ReactNoop = require('react-noop-renderer');
     const InternalTestUtils = require('internal-test-utils');
     waitForAll = InternalTestUtils.waitForAll;
-    if (__DEV__) {
-      JSXDEVRuntime = require('react/jsx-dev-runtime');
-    }
   });
 
   // @gate !disableDefaultPropsExceptForClasses || !__DEV__
@@ -65,117 +61,4 @@ describe('ReactDeprecationWarnings', () => {
         'release. Use JavaScript default parameters instead.',
     );
   });
-
-  // @gate !disableStringRefs
-  it('should warn when given string refs', async () => {
-    class RefComponent extends React.Component {
-      render() {
-        return null;
-      }
-    }
-    class Component extends React.Component {
-      render() {
-        return <RefComponent ref="refComponent" />;
-      }
-    }
-
-    ReactNoop.render(<Component />);
-    await expect(async () => await waitForAll([])).toErrorDev(
-      'Component "Component" contains the string ref "refComponent". ' +
-        'Support for string refs will be removed in a future major release. ' +
-        'We recommend using useRef() or createRef() instead. ' +
-        'Learn more about using refs safely here: ' +
-        'https://react.dev/link/strict-mode-string-ref' +
-        '\n    in RefComponent (at **)' +
-        '\n    in Component (at **)',
-    );
-  });
-
-  // Disabling this until #28732 lands so we can assert on the warning message.
-  // (It's already disabled in all but the Meta builds, anyway. Nbd.)
-  // @gate TODO || !__DEV__
-  // @gate !disableStringRefs
-  it('should warn when owner and self are the same for string refs', async () => {
-    class RefComponent extends React.Component {
-      render() {
-        return null;
-      }
-    }
-    class Component extends React.Component {
-      render() {
-        return React.createElement(RefComponent, {
-          ref: 'refComponent',
-          __self: this,
-        });
-      }
-    }
-
-    ReactNoop.render(<Component />);
-    await expect(async () => await waitForAll([])).toErrorDev([
-      'Component "Component" contains the string ref "refComponent". Support for string refs will be removed in a future major release.',
-    ]);
-    await waitForAll([]);
-  });
-
-  // Disabling this until #28732 lands so we can assert on the warning message.
-  // (It's already disabled in all but the Meta builds, anyway. Nbd.)
-  // @gate TODO || !__DEV__
-  // @gate !disableStringRefs
-  it('should warn when owner and self are different for string refs (createElement)', async () => {
-    class RefComponent extends React.Component {
-      render() {
-        return null;
-      }
-    }
-    class Component extends React.Component {
-      render() {
-        return React.createElement(RefComponent, {
-          ref: 'refComponent',
-          __self: {},
-        });
-      }
-    }
-
-    ReactNoop.render(<Component />);
-    await expect(async () => await waitForAll([])).toErrorDev([
-      'Component "Component" contains the string ref "refComponent". ' +
-        'Support for string refs will be removed in a future major release. ' +
-        'This case cannot be automatically converted to an arrow function. ' +
-        'We ask you to manually fix this case by using useRef() or createRef() instead. ' +
-        'Learn more about using refs safely here: ' +
-        'https://react.dev/link/strict-mode-string-ref',
-    ]);
-  });
-
-  // @gate __DEV__
-  // @gate !disableStringRefs
-  it('should warn when owner and self are different for string refs (jsx)', async () => {
-    class RefComponent extends React.Component {
-      render() {
-        return null;
-      }
-    }
-    class Component extends React.Component {
-      render() {
-        return JSXDEVRuntime.jsxDEV(
-          RefComponent,
-          {ref: 'refComponent'},
-          null,
-          false,
-          {},
-          {},
-        );
-      }
-    }
-
-    ReactNoop.render(<Component />);
-    await expect(async () => await waitForAll([])).toErrorDev([
-      'Component "Component" contains the string ref "refComponent". ' +
-        'Support for string refs will be removed in a future major release. ' +
-        'This case cannot be automatically converted to an arrow function. ' +
-        'We ask you to manually fix this case by using useRef() or createRef() instead. ' +
-        'Learn more about using refs safely here: ' +
-        'https://react.dev/link/strict-mode-string-ref',
-    ]);
-  });
 });
diff --git a/packages/react-dom/src/__tests__/ReactFunctionComponent-test.js b/packages/react-dom/src/__tests__/ReactFunctionComponent-test.js
index 24f97520ecc3..f1250ce26d7c 100644
--- a/packages/react-dom/src/__tests__/ReactFunctionComponent-test.js
+++ b/packages/react-dom/src/__tests__/ReactFunctionComponent-test.js
@@ -179,24 +179,6 @@ describe('ReactFunctionComponent', () => {
     ).resolves.not.toThrowError();
   });
 
-  // @gate !disableStringRefs
-  it('should throw on string refs in pure functions', async () => {
-    function Child() {
-      return <div ref="me" />;
-    }
-
-    const container = document.createElement('div');
-    const root = ReactDOMClient.createRoot(container);
-    await expect(
-      act(() => {
-        root.render(<Child test="test" />);
-      }),
-    )
-      // TODO: This throws an AggregateError. Need to update test infra to
-      // support matching against AggregateError.
-      .rejects.toThrowError();
-  });
-
   it('should use correct name in key warning', async () => {
     function Child() {
       return <div>{[<span />]}</div>;
diff --git a/packages/react-dom/src/__tests__/multiple-copies-of-react-test.js b/packages/react-dom/src/__tests__/multiple-copies-of-react-test.js
deleted file mode 100644
index 2d107cbb1970..000000000000
--- a/packages/react-dom/src/__tests__/multiple-copies-of-react-test.js
+++ /dev/null
@@ -1,38 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- *
- * @emails react-core
- */
-
-'use strict';
-
-let React = require('react');
-const ReactDOMClient = require('react-dom/client');
-const act = require('internal-test-utils').act;
-
-class TextWithStringRef extends React.Component {
-  render() {
-    jest.resetModules();
-    React = require('react');
-    return <span ref="foo">Hello world!</span>;
-  }
-}
-
-describe('when different React version is used with string ref', () => {
-  // @gate !disableStringRefs
-  it('throws the "Refs must have owner" warning', async () => {
-    const container = document.createElement('div');
-    const root = ReactDOMClient.createRoot(container);
-    await expect(
-      act(() => {
-        root.render(<TextWithStringRef />);
-      }),
-    )
-      // TODO: This throws an AggregateError. Need to update test infra to
-      // support matching against AggregateError.
-      .rejects.toThrow();
-  });
-});
diff --git a/packages/react-dom/src/__tests__/refs-test.js b/packages/react-dom/src/__tests__/refs-test.js
index 80ea8d1e26b3..b80f8b27753f 100644
--- a/packages/react-dom/src/__tests__/refs-test.js
+++ b/packages/react-dom/src/__tests__/refs-test.js
@@ -13,179 +13,6 @@ const React = require('react');
 const ReactDOMClient = require('react-dom/client');
 const act = require('internal-test-utils').act;
 
-// This is testing if string refs are deleted from `instance.refs`
-// Once support for string refs is removed, this test can be removed.
-// Detaching is already tested in refs-detruction-test.js
-describe('reactiverefs', () => {
-  let container;
-
-  afterEach(() => {
-    if (container) {
-      document.body.removeChild(container);
-      container = null;
-    }
-  });
-
-  /**
-   * Counts clicks and has a renders an item for each click. Each item rendered
-   * has a ref of the form "clickLogN".
-   */
-  class ClickCounter extends React.Component {
-    state = {count: this.props.initialCount};
-
-    triggerReset = () => {
-      this.setState({count: this.props.initialCount});
-    };
-
-    handleClick = () => {
-      this.setState({count: this.state.count + 1});
-    };
-
-    render() {
-      const children = [];
-      let i;
-      for (i = 0; i < this.state.count; i++) {
-        children.push(
-          <div
-            className="clickLogDiv"
-            key={'clickLog' + i}
-            ref={'clickLog' + i}
-          />,
-        );
-      }
-      return (
-        <span className="clickIncrementer" onClick={this.handleClick}>
-          {children}
-        </span>
-      );
-    }
-  }
-
-  const expectClickLogsLengthToBe = function (instance, length) {
-    const clickLogs = instance.container.querySelectorAll('.clickLogDiv');
-    expect(clickLogs.length).toBe(length);
-    expect(Object.keys(instance.refs.myCounter.refs).length).toBe(length);
-  };
-
-  /**
-   * Render a TestRefsComponent and ensure that the main refs are wired up.
-   */
-  const renderTestRefsComponent = async function () {
-    /**
-     * Only purpose is to test that refs are tracked even when applied to a
-     * component that is injected down several layers. Ref systems are difficult to
-     * build in such a way that ownership is maintained in an airtight manner.
-     */
-    class GeneralContainerComponent extends React.Component {
-      render() {
-        return <div>{this.props.children}</div>;
-      }
-    }
-
-    /**
-     * Notice how refs ownership is maintained even when injecting a component
-     * into a different parent.
-     */
-    class TestRefsComponent extends React.Component {
-      container = null;
-      doReset = () => {
-        this.refs.myCounter.triggerReset();
-      };
-
-      render() {
-        return (
-          <div ref={current => (this.container = current)}>
-            <div ref="resetDiv" onClick={this.doReset}>
-              Reset Me By Clicking This.
-            </div>
-            <GeneralContainerComponent ref="myContainer">
-              <ClickCounter ref="myCounter" initialCount={1} />
-            </GeneralContainerComponent>
-          </div>
-        );
-      }
-    }
-
-    container = document.createElement('div');
-    document.body.appendChild(container);
-
-    let testRefsComponent;
-    await expect(async () => {
-      const root = ReactDOMClient.createRoot(container);
-      await act(() => {
-        root.render(
-          <TestRefsComponent
-            ref={current => {
-              testRefsComponent = current;
-            }}
-          />,
-        );
-      });
-    }).toErrorDev([
-      'Component "TestRefsComponent" contains the string ' +
-        'ref "resetDiv". Support for string refs will be removed in a ' +
-        'future major release. We recommend using useRef() or createRef() ' +
-        'instead. Learn more about using refs safely ' +
-        'here: https://react.dev/link/strict-mode-string-ref\n' +
-        '    in div (at **)\n' +
-        '    in div (at **)\n' +
-        '    in TestRefsComponent (at **)',
-      'Component "ClickCounter" contains the string ' +
-        'ref "clickLog0". Support for string refs will be removed in a ' +
-        'future major release. We recommend using useRef() or createRef() ' +
-        'instead. Learn more about using refs safely ' +
-        'here: https://react.dev/link/strict-mode-string-ref\n' +
-        '    in div (at **)\n' +
-        '    in span (at **)\n' +
-        '    in ClickCounter (at **)',
-    ]);
-
-    expect(testRefsComponent instanceof TestRefsComponent).toBe(true);
-
-    const generalContainer = testRefsComponent.refs.myContainer;
-    expect(generalContainer instanceof GeneralContainerComponent).toBe(true);
-
-    const counter = testRefsComponent.refs.myCounter;
-    expect(counter instanceof ClickCounter).toBe(true);
-
-    return testRefsComponent;
-  };
-
-  /**
-   * Ensure that for every click log there is a corresponding ref (from the
-   * perspective of the injected ClickCounter component.
-   */
-  // @gate !disableStringRefs
-  it('Should increase refs with an increase in divs', async () => {
-    const testRefsComponent = await renderTestRefsComponent();
-    const clickIncrementer =
-      testRefsComponent.container.querySelector('.clickIncrementer');
-
-    expectClickLogsLengthToBe(testRefsComponent, 1);
-
-    // After clicking the reset, there should still only be one click log ref.
-    testRefsComponent.refs.resetDiv.click();
-    expectClickLogsLengthToBe(testRefsComponent, 1);
-
-    // Begin incrementing clicks (and therefore refs).
-    await act(() => {
-      clickIncrementer.click();
-    });
-    expectClickLogsLengthToBe(testRefsComponent, 2);
-
-    await act(() => {
-      clickIncrementer.click();
-    });
-    expectClickLogsLengthToBe(testRefsComponent, 3);
-
-    // Now reset again
-    await act(() => {
-      testRefsComponent.refs.resetDiv.click();
-    });
-    expectClickLogsLengthToBe(testRefsComponent, 1);
-  });
-});
-
 /**
  * Tests that when a ref hops around children, we can track that correctly.
  */
@@ -320,32 +147,6 @@ describe('ref swapping', () => {
     expect(refCalled).toBe(1);
   });
 
-  // @gate !disableStringRefs
-  it('coerces numbers to strings', async () => {
-    class A extends React.Component {
-      render() {
-        return <div ref={1} />;
-      }
-    }
-    let a;
-    await expect(async () => {
-      const container = document.createElement('div');
-      const root = ReactDOMClient.createRoot(container);
-
-      await act(() => {
-        root.render(<A ref={current => (a = current)} />);
-      });
-    }).toErrorDev([
-      'Component "A" contains the string ref "1". ' +
-        'Support for string refs will be removed in a future major release. ' +
-        'We recommend using useRef() or createRef() instead. ' +
-        'Learn more about using refs safely here: https://react.dev/link/strict-mode-string-ref\n' +
-        '    in div (at **)\n' +
-        '    in A (at **)',
-    ]);
-    expect(a.refs[1].nodeName).toBe('DIV');
-  });
-
   it('provides an error for invalid refs', async () => {
     const container = document.createElement('div');
     const root = ReactDOMClient.createRoot(container);
@@ -469,108 +270,6 @@ describe('root level refs', () => {
   });
 });
 
-describe('creating element with string ref in constructor', () => {
-  class RefTest extends React.Component {
-    constructor(props) {
-      super(props);
-      this.p = <p ref="p">Hello!</p>;
-    }
-
-    render() {
-      return <div>{this.p}</div>;
-    }
-  }
-
-  // @gate !disableStringRefs && !__DEV__
-  it('throws an error in prod', async () => {
-    await expect(async function () {
-      const container = document.createElement('div');
-      const root = ReactDOMClient.createRoot(container);
-
-      await act(() => {
-        root.render(<RefTest />);
-      });
-    })
-      // TODO: This throws an AggregateError. Need to update test infra to
-      // support matching against AggregateError.
-      .rejects.toThrowError();
-  });
-});
-
-describe('strings refs across renderers', () => {
-  // @gate !disableStringRefs
-  it('does not break', async () => {
-    class Parent extends React.Component {
-      render() {
-        // This component owns both refs.
-        return (
-          <Indirection
-            child1={<div ref="child1" />}
-            child2={<div ref="child2" />}
-          />
-        );
-      }
-    }
-
-    class Indirection extends React.Component {
-      componentDidUpdate() {
-        // One ref is being rendered later using another renderer copy.
-        jest.resetModules();
-        const AnotherCopyOfReactDOM = require('react-dom');
-        const AnotherCopyOfReactDOMClient = require('react-dom/client');
-        const root = AnotherCopyOfReactDOMClient.createRoot(div2);
-        AnotherCopyOfReactDOM.flushSync(() => {
-          root.render(this.props.child2);
-        });
-      }
-      render() {
-        // The other one is being rendered directly.
-        return this.props.child1;
-      }
-    }
-
-    const div1 = document.createElement('div');
-    const div2 = document.createElement('div');
-
-    const root = ReactDOMClient.createRoot(div1);
-    let inst;
-    await expect(async () => {
-      await act(() => {
-        root.render(
-          <Parent
-            ref={current => {
-              if (current !== null) {
-                inst = current;
-              }
-            }}
-          />,
-        );
-      });
-    }).toErrorDev([
-      'Component "Parent" contains the string ref "child1". ' +
-        'Support for string refs will be removed in a future major release. ' +
-        'We recommend using useRef() or createRef() instead. ' +
-        'Learn more about using refs safely here: https://react.dev/link/strict-mode-string-ref\n' +
-        '    in div (at **)\n' +
-        '    in Indirection (at **)\n' +
-        '    in Parent (at **)',
-    ]);
-
-    // Only the first ref has rendered yet.
-    expect(inst.refs.child1.tagName).toBe('DIV');
-    expect(inst.refs.child1).toBe(div1.firstChild);
-
-    // Now both refs should be rendered.
-    await act(() => {
-      root.render(<Parent />);
-    });
-    expect(inst.refs.child1.tagName).toBe('DIV');
-    expect(inst.refs.child1).toBe(div1.firstChild);
-    expect(inst.refs.child2.tagName).toBe('DIV');
-    expect(inst.refs.child2).toBe(div2.firstChild);
-  });
-});
-
 describe('refs return clean up function', () => {
   it('calls clean up function if it exists', async () => {
     const container = document.createElement('div');
diff --git a/packages/react-noop-renderer/src/createReactNoop.js b/packages/react-noop-renderer/src/createReactNoop.js
index 3e95e537e9dd..4c1bf05e5404 100644
--- a/packages/react-noop-renderer/src/createReactNoop.js
+++ b/packages/react-noop-renderer/src/createReactNoop.js
@@ -35,7 +35,7 @@ import {
   ConcurrentRoot,
   LegacyRoot,
 } from 'react-reconciler/constants';
-import {disableLegacyMode, disableStringRefs} from 'shared/ReactFeatureFlags';
+import {disableLegacyMode} from 'shared/ReactFeatureFlags';
 
 import ReactSharedInternals from 'shared/ReactSharedInternals';
 import ReactVersion from 'shared/ReactVersion';
@@ -843,14 +843,6 @@ 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,
@@ -858,8 +850,6 @@ function createReactNoop(reconciler: Function, useMutation: boolean) {
         key: null,
         ref: null,
         props: props,
-        _owner: null,
-        _store: __DEV__ ? {} : undefined,
       };
     }
   }
diff --git a/packages/react-reconciler/src/ReactFiberAsyncDispatcher.js b/packages/react-reconciler/src/ReactFiberAsyncDispatcher.js
index d329fb369cae..0d6856f5d0ac 100644
--- a/packages/react-reconciler/src/ReactFiberAsyncDispatcher.js
+++ b/packages/react-reconciler/src/ReactFiberAsyncDispatcher.js
@@ -14,8 +14,6 @@ import {enableCache} from 'shared/ReactFeatureFlags';
 import {readContext} from './ReactFiberNewContext';
 import {CacheContext} from './ReactFiberCacheComponent';
 
-import {disableStringRefs} from 'shared/ReactFeatureFlags';
-
 import {current as currentOwner} from './ReactCurrentFiber';
 
 function getCacheForType<T>(resourceType: () => T): T {
@@ -35,7 +33,7 @@ export const DefaultAsyncDispatcher: AsyncDispatcher = ({
   getCacheForType,
 }: any);
 
-if (__DEV__ || !disableStringRefs) {
+if (__DEV__) {
   DefaultAsyncDispatcher.getOwner = (): null | Fiber => {
     return currentOwner;
   };
diff --git a/packages/react-reconciler/src/ReactFiberBeginWork.js b/packages/react-reconciler/src/ReactFiberBeginWork.js
index efb34826c970..0a5457d20c33 100644
--- a/packages/react-reconciler/src/ReactFiberBeginWork.js
+++ b/packages/react-reconciler/src/ReactFiberBeginWork.js
@@ -110,7 +110,6 @@ import {
   enableRenderableContext,
   disableLegacyMode,
   disableDefaultPropsExceptForClasses,
-  disableStringRefs,
   enableOwnerStacks,
 } from 'shared/ReactFeatureFlags';
 import isArray from 'shared/isArray';
@@ -1052,25 +1051,6 @@ function markRef(current: Fiber | null, workInProgress: Fiber) {
       );
     }
     if (current === null || current.ref !== ref) {
-      if (!disableStringRefs && current !== null) {
-        const oldRef = current.ref;
-        const newRef = ref;
-        if (
-          typeof oldRef === 'function' &&
-          typeof newRef === 'function' &&
-          typeof oldRef.__stringRef === 'string' &&
-          oldRef.__stringRef === newRef.__stringRef &&
-          oldRef.__stringRefType === newRef.__stringRefType &&
-          oldRef.__stringRefOwner === newRef.__stringRefOwner
-        ) {
-          // Although this is a different callback, it represents the same
-          // string ref. To avoid breaking old Meta code that relies on string
-          // refs only being attached once, reuse the old ref. This will
-          // prevent us from detaching and reattaching the ref on each update.
-          workInProgress.ref = oldRef;
-          return;
-        }
-      }
       // Schedule a Ref effect
       workInProgress.flags |= Ref | RefStatic;
     }
@@ -1388,7 +1368,7 @@ function finishClassComponent(
   const instance = workInProgress.stateNode;
 
   // Rerender
-  if (__DEV__ || !disableStringRefs) {
+  if (__DEV__) {
     setCurrentFiber(workInProgress);
   }
   let nextChildren;
diff --git a/packages/react-reconciler/src/ReactFiberCommitEffects.js b/packages/react-reconciler/src/ReactFiberCommitEffects.js
index 4d10c9ee6faf..70c49bc62fae 100644
--- a/packages/react-reconciler/src/ReactFiberCommitEffects.js
+++ b/packages/react-reconciler/src/ReactFiberCommitEffects.js
@@ -18,7 +18,6 @@ import {
   enableProfilerNestedUpdatePhase,
   enableSchedulingProfiler,
   enableScopeAPI,
-  disableStringRefs,
 } from 'shared/ReactFeatureFlags';
 import {
   ClassComponent,
@@ -773,7 +772,7 @@ function commitAttachRef(finishedWork: Fiber) {
       if (__DEV__) {
         // TODO: We should move these warnings to happen during the render
         // phase (markRef).
-        if (disableStringRefs && typeof ref === 'string') {
+        if (typeof ref === 'string') {
           console.error('String refs are no longer supported.');
         } else if (!ref.hasOwnProperty('current')) {
           console.error(
diff --git a/packages/react-reconciler/src/ReactFiberWorkLoop.js b/packages/react-reconciler/src/ReactFiberWorkLoop.js
index aa5884444063..1ea05dd010a8 100644
--- a/packages/react-reconciler/src/ReactFiberWorkLoop.js
+++ b/packages/react-reconciler/src/ReactFiberWorkLoop.js
@@ -40,7 +40,6 @@ import {
   enableInfiniteRenderLoopDetection,
   disableLegacyMode,
   disableDefaultPropsExceptForClasses,
-  disableStringRefs,
   enableSiblingPrerendering,
   enableComponentPerformanceTrack,
 } from 'shared/ReactFeatureFlags';
@@ -1732,7 +1731,7 @@ function handleThrow(root: FiberRoot, thrownValue: any): void {
   // These should be reset immediately because they're only supposed to be set
   // when React is executing user code.
   resetHooksAfterThrow();
-  if (__DEV__ || !disableStringRefs) {
+  if (__DEV__) {
     resetCurrentFiber();
   }
 
@@ -1928,7 +1927,7 @@ function popDispatcher(prevDispatcher: any) {
 }
 
 function pushAsyncDispatcher() {
-  if (enableCache || __DEV__ || !disableStringRefs) {
+  if (enableCache || __DEV__) {
     const prevAsyncDispatcher = ReactSharedInternals.A;
     ReactSharedInternals.A = DefaultAsyncDispatcher;
     return prevAsyncDispatcher;
@@ -1938,7 +1937,7 @@ function pushAsyncDispatcher() {
 }
 
 function popAsyncDispatcher(prevAsyncDispatcher: any) {
-  if (enableCache || __DEV__ || !disableStringRefs) {
+  if (enableCache || __DEV__) {
     ReactSharedInternals.A = prevAsyncDispatcher;
   }
 }
@@ -2497,9 +2496,6 @@ function performUnitOfWork(unitOfWork: Fiber): void {
     }
   }
 
-  if (!disableStringRefs) {
-    resetCurrentFiber();
-  }
   unitOfWork.memoizedProps = unitOfWork.pendingProps;
   if (next === null) {
     // If this doesn't spawn new work, complete the current work.
@@ -2519,11 +2515,6 @@ function replaySuspendedUnitOfWork(unitOfWork: Fiber): void {
     next = replayBeginWork(unitOfWork);
   }
 
-  // The begin phase finished successfully without suspending. Return to the
-  // normal work loop.
-  if (!disableStringRefs) {
-    resetCurrentFiber();
-  }
   unitOfWork.memoizedProps = unitOfWork.pendingProps;
   if (next === null) {
     // If this doesn't spawn new work, complete the current work.
diff --git a/packages/react-reconciler/src/ReactInternalTypes.js b/packages/react-reconciler/src/ReactInternalTypes.js
index 1c98a9e9c7fb..d91727525c96 100644
--- a/packages/react-reconciler/src/ReactInternalTypes.js
+++ b/packages/react-reconciler/src/ReactInternalTypes.js
@@ -460,6 +460,6 @@ export type Dispatcher = {
 
 export type AsyncDispatcher = {
   getCacheForType: <T>(resourceType: () => T) => T,
-  // DEV-only (or !disableStringRefs)
+  // DEV-only
   getOwner: () => null | Fiber | ReactComponentInfo | ComponentStackNode,
 };
diff --git a/packages/react-reconciler/src/__tests__/ReactFiberRefs-test.js b/packages/react-reconciler/src/__tests__/ReactFiberRefs-test.js
index 8fd5206c94ae..78409c8e2a4e 100644
--- a/packages/react-reconciler/src/__tests__/ReactFiberRefs-test.js
+++ b/packages/react-reconciler/src/__tests__/ReactFiberRefs-test.js
@@ -85,35 +85,6 @@ describe('ReactFiberRefs', () => {
     expect(ref2.current).not.toBe(null);
   });
 
-  // @gate !disableStringRefs
-  it('string ref props are converted to function refs', async () => {
-    let refProp;
-    function Child({ref}) {
-      refProp = ref;
-      return <div ref={ref} />;
-    }
-
-    let owner;
-    class Owner extends React.Component {
-      render() {
-        owner = this;
-        return <Child ref="child" />;
-      }
-    }
-
-    const root = ReactNoop.createRoot();
-    await act(() => root.render(<Owner />));
-
-    // When string refs aren't disabled, string refs
-    // the receiving component receives a callback ref, not the original string.
-    // This behavior should never be shipped to open source; it's only here to
-    // allow Meta to keep using string refs temporarily while they finish
-    // migrating their codebase.
-    expect(typeof refProp === 'function').toBe(true);
-    expect(owner.refs.child.type).toBe('div');
-  });
-
-  // @gate disableStringRefs
   it('throw if a string ref is passed to a ref-receiving component', async () => {
     let refProp;
     function Child({ref}) {
diff --git a/packages/react-reconciler/src/__tests__/ReactIncrementalSideEffects-test.js b/packages/react-reconciler/src/__tests__/ReactIncrementalSideEffects-test.js
index 81f892b48e35..c4473c1774e9 100644
--- a/packages/react-reconciler/src/__tests__/ReactIncrementalSideEffects-test.js
+++ b/packages/react-reconciler/src/__tests__/ReactIncrementalSideEffects-test.js
@@ -1334,38 +1334,4 @@ describe('ReactIncrementalSideEffects', () => {
 
   // TODO: Test that mounts, updates, refs, unmounts and deletions happen in the
   // expected way for aborted and resumed render life-cycles.
-
-  // @gate !disableStringRefs
-  it('supports string refs', async () => {
-    let fooInstance = null;
-
-    class Bar extends React.Component {
-      componentDidMount() {
-        this.test = 'test';
-      }
-      render() {
-        return <div />;
-      }
-    }
-
-    class Foo extends React.Component {
-      render() {
-        fooInstance = this;
-        return <Bar ref="bar" />;
-      }
-    }
-
-    ReactNoop.render(<Foo />);
-    await expect(async () => {
-      await waitForAll([]);
-    }).toErrorDev([
-      'Component "Foo" contains the string ref "bar". ' +
-        'Support for string refs will be removed in a future major release. ' +
-        'We recommend using useRef() or createRef() instead. ' +
-        'Learn more about using refs safely here: https://react.dev/link/strict-mode-string-ref\n' +
-        '    in Bar (at **)\n' +
-        '    in Foo (at **)',
-    ]);
-    expect(fooInstance.refs.bar.test).toEqual('test');
-  });
 });
diff --git a/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOMEdge-test.js b/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOMEdge-test.js
index ed349cde81f0..1a097ffbda56 100644
--- a/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOMEdge-test.js
+++ b/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOMEdge-test.js
@@ -1001,9 +1001,7 @@ describe('ReactFlightDOMEdge', () => {
       expect(greeting._owner).toBe(lazyWrapper._debugInfo[0]);
     } else {
       expect(lazyWrapper._debugInfo).toBe(undefined);
-      expect(greeting._owner).toBe(
-        gate(flags => flags.disableStringRefs) ? undefined : null,
-      );
+      expect(greeting._owner).toBe(undefined);
     }
   });
 
diff --git a/packages/react-server/src/ReactFizzAsyncDispatcher.js b/packages/react-server/src/ReactFizzAsyncDispatcher.js
index 3a548ae13803..e4d940d463c2 100644
--- a/packages/react-server/src/ReactFizzAsyncDispatcher.js
+++ b/packages/react-server/src/ReactFizzAsyncDispatcher.js
@@ -10,8 +10,6 @@
 import type {AsyncDispatcher} from 'react-reconciler/src/ReactInternalTypes';
 import type {ComponentStackNode} from './ReactFizzComponentStack';
 
-import {disableStringRefs} from 'shared/ReactFeatureFlags';
-
 import {currentTaskInDEV} from './ReactFizzCurrentTask';
 
 function getCacheForType<T>(resourceType: () => T): T {
@@ -29,8 +27,4 @@ if (__DEV__) {
     }
     return currentTaskInDEV.componentStack;
   };
-} else if (!disableStringRefs) {
-  DefaultAsyncDispatcher.getOwner = (): null => {
-    return null;
-  };
 }
diff --git a/packages/react-server/src/ReactFizzServer.js b/packages/react-server/src/ReactFizzServer.js
index 7b881fdbe8cc..f245861ba001 100644
--- a/packages/react-server/src/ReactFizzServer.js
+++ b/packages/react-server/src/ReactFizzServer.js
@@ -162,7 +162,6 @@ import {
   enableRenderableContext,
   disableDefaultPropsExceptForClasses,
   enableAsyncIterableChildren,
-  disableStringRefs,
   enableOwnerStacks,
 } from 'shared/ReactFeatureFlags';
 
@@ -4452,7 +4451,7 @@ export function performWork(request: Request): void {
   const prevDispatcher = ReactSharedInternals.H;
   ReactSharedInternals.H = HooksDispatcher;
   let prevAsyncDispatcher = null;
-  if (enableCache || __DEV__ || !disableStringRefs) {
+  if (enableCache || __DEV__) {
     prevAsyncDispatcher = ReactSharedInternals.A;
     ReactSharedInternals.A = DefaultAsyncDispatcher;
   }
diff --git a/packages/react-server/src/flight/ReactFlightAsyncDispatcher.js b/packages/react-server/src/flight/ReactFlightAsyncDispatcher.js
index f5f031a860ff..00c1abf33292 100644
--- a/packages/react-server/src/flight/ReactFlightAsyncDispatcher.js
+++ b/packages/react-server/src/flight/ReactFlightAsyncDispatcher.js
@@ -7,14 +7,9 @@
  * @flow
  */
 
-import type {ReactComponentInfo} from 'shared/ReactTypes';
-
 import type {AsyncDispatcher} from 'react-reconciler/src/ReactInternalTypes';
 
 import {resolveRequest, getCache} from '../ReactFlightServer';
-
-import {disableStringRefs} from 'shared/ReactFeatureFlags';
-
 import {resolveOwner} from './ReactFlightCurrentOwner';
 
 function resolveCache(): Map<Function, mixed> {
@@ -40,9 +35,4 @@ export const DefaultAsyncDispatcher: AsyncDispatcher = ({
 
 if (__DEV__) {
   DefaultAsyncDispatcher.getOwner = resolveOwner;
-} else if (!disableStringRefs) {
-  // Server Components never use string refs but the JSX runtime looks for it.
-  DefaultAsyncDispatcher.getOwner = (): null | ReactComponentInfo => {
-    return null;
-  };
 }
diff --git a/packages/react/src/__tests__/ReactCoffeeScriptClass-test.coffee b/packages/react/src/__tests__/ReactCoffeeScriptClass-test.coffee
index 22ef789f4f6e..3ad6aa023518 100644
--- a/packages/react/src/__tests__/ReactCoffeeScriptClass-test.coffee
+++ b/packages/react/src/__tests__/ReactCoffeeScriptClass-test.coffee
@@ -551,25 +551,4 @@ describe 'ReactCoffeeScriptClass', ->
         ],
       )
 
-  if !featureFlags.disableStringRefs
-    it 'supports string refs', ->
-      class Foo extends React.Component
-        render: ->
-          React.createElement(InnerComponent,
-            name: 'foo'
-            ref: 'inner'
-          )
-
-      ref = React.createRef()
-      expect(->
-        test(React.createElement(Foo, ref: ref), 'DIV', 'foo')
-      ).toErrorDev([
-        'Component "Foo" contains the string ref "inner". ' +
-          'Support for string refs will be removed in a future major release. ' +
-          'We recommend using useRef() or createRef() instead. ' +
-          'Learn more about using refs safely here: https://react.dev/link/strict-mode-string-ref\n' +
-          '    in _Class (at **)'
-      ]);
-      expect(ref.current.refs.inner.getName()).toBe 'foo'
-
   undefined
diff --git a/packages/react/src/__tests__/ReactCreateElement-test.js b/packages/react/src/__tests__/ReactCreateElement-test.js
index 3ab5c34c3304..392f89979e76 100644
--- a/packages/react/src/__tests__/ReactCreateElement-test.js
+++ b/packages/react/src/__tests__/ReactCreateElement-test.js
@@ -218,7 +218,7 @@ describe('ReactCreateElement', () => {
     }
     const root = ReactDOMClient.createRoot(document.createElement('div'));
     await act(() => root.render(React.createElement(Wrapper)));
-    if (__DEV__ || !gate(flags => flags.disableStringRefs)) {
+    if (__DEV__) {
       expect(element._owner.stateNode).toBe(instance);
     } else {
       expect('_owner' in element).toBe(false);
diff --git a/packages/react/src/__tests__/ReactES6Class-test.js b/packages/react/src/__tests__/ReactES6Class-test.js
index 3ac0b18e8e75..eceeab18c5bb 100644
--- a/packages/react/src/__tests__/ReactES6Class-test.js
+++ b/packages/react/src/__tests__/ReactES6Class-test.js
@@ -592,25 +592,4 @@ describe('ReactES6Class', () => {
       ]);
     });
   }
-
-  if (!require('shared/ReactFeatureFlags').disableStringRefs) {
-    it('supports string refs', () => {
-      class Foo extends React.Component {
-        render() {
-          return <Inner name="foo" ref="inner" />;
-        }
-      }
-      const ref = React.createRef();
-      expect(() => {
-        runTest(<Foo ref={ref} />, 'DIV', 'foo');
-      }).toErrorDev([
-        'Component "Foo" contains the string ref "inner". ' +
-          'Support for string refs will be removed in a future major release. ' +
-          'We recommend using useRef() or createRef() instead. ' +
-          'Learn more about using refs safely here: https://react.dev/link/strict-mode-string-ref\n' +
-          '    in Inner (at **)',
-      ]);
-      expect(ref.current.refs.inner.getName()).toBe('foo');
-    });
-  }
 });
diff --git a/packages/react/src/__tests__/ReactElementClone-test.js b/packages/react/src/__tests__/ReactElementClone-test.js
index 4e7d0c5ca2a2..fb0bfe2df8d6 100644
--- a/packages/react/src/__tests__/ReactElementClone-test.js
+++ b/packages/react/src/__tests__/ReactElementClone-test.js
@@ -270,49 +270,8 @@ describe('ReactElementClone', () => {
 
     const root = ReactDOMClient.createRoot(document.createElement('div'));
     await act(() => root.render(<Grandparent />));
-    if (gate(flags => flags.disableStringRefs)) {
-      expect(component.childRef).toEqual({current: null});
-      expect(component.parentRef.current.xyzRef.current.tagName).toBe('SPAN');
-    } else if (gate(flags => !flags.disableStringRefs)) {
-      expect(component.childRef).toEqual({current: null});
-      expect(component.parentRef.current.xyzRef.current.tagName).toBe('SPAN');
-    } else {
-      // Not going to bother testing every possible combination.
-    }
-  });
-
-  // @gate !disableStringRefs
-  it('should steal the ref if a new string ref is specified without an owner', async () => {
-    // Regression test for this specific feature combination calling cloneElement on an element
-    // without an owner
-    await expect(async () => {
-      // create an element without an owner
-      const element = React.createElement('div', {id: 'some-id'});
-      class Parent extends React.Component {
-        render() {
-          return <Child>{element}</Child>;
-        }
-      }
-      let child;
-      class Child extends React.Component {
-        render() {
-          child = this;
-          const clone = React.cloneElement(this.props.children, {
-            ref: 'xyz',
-          });
-          return <div>{clone}</div>;
-        }
-      }
-
-      const root = ReactDOMClient.createRoot(document.createElement('div'));
-      await act(() => root.render(<Parent />));
-      expect(child.refs.xyz.tagName).toBe('DIV');
-    }).toErrorDev([
-      'Component "Child" contains the string ref "xyz". Support for ' +
-        'string refs will be removed in a future major release. We recommend ' +
-        'using useRef() or createRef() instead. Learn more about using refs ' +
-        'safely here: https://react.dev/link/strict-mode-string-ref',
-    ]);
+    expect(component.childRef).toEqual({current: null});
+    expect(component.parentRef.current.xyzRef.current.tagName).toBe('SPAN');
   });
 
   it('should overwrite props', async () => {
@@ -403,23 +362,12 @@ describe('ReactElementClone', () => {
     const clone = React.cloneElement(element, props);
     expect(clone.type).toBe(ComponentClass);
     expect(clone.key).toBe('12');
-    if (gate(flags => flags.disableStringRefs)) {
-      expect(clone.props.ref).toBe('34');
-      expect(() => expect(clone.ref).toBe('34')).toErrorDev(
-        'Accessing element.ref was removed in React 19',
-        {withoutStack: true},
-      );
-      expect(clone.props).toEqual({foo: 'ef', ref: '34'});
-    } else if (gate(flags => !flags.disableStringRefs)) {
-      expect(() => {
-        expect(clone.ref).toBe(element.ref);
-      }).toErrorDev('Accessing element.ref was removed in React 19', {
-        withoutStack: true,
-      });
-      expect(clone.props).toEqual({foo: 'ef', ref: element.ref});
-    } else {
-      // Not going to bother testing every possible combination.
-    }
+    expect(clone.props.ref).toBe('34');
+    expect(() => expect(clone.ref).toBe('34')).toErrorDev(
+      'Accessing element.ref was removed in React 19',
+      {withoutStack: true},
+    );
+    expect(clone.props).toEqual({foo: 'ef', ref: '34'});
     if (__DEV__) {
       expect(Object.isFrozen(element)).toBe(true);
       expect(Object.isFrozen(element.props)).toBe(true);
diff --git a/packages/react/src/__tests__/ReactStrictMode-test.js b/packages/react/src/__tests__/ReactStrictMode-test.js
index 2ab9c3fa18c9..97fcc1ec8c4c 100644
--- a/packages/react/src/__tests__/ReactStrictMode-test.js
+++ b/packages/react/src/__tests__/ReactStrictMode-test.js
@@ -956,55 +956,6 @@ describe('symbol checks', () => {
   });
 });
 
-describe('string refs', () => {
-  beforeEach(() => {
-    jest.resetModules();
-    React = require('react');
-    ReactDOM = require('react-dom');
-    ReactDOMClient = require('react-dom/client');
-    act = require('internal-test-utils').act;
-  });
-
-  // @gate !disableStringRefs
-  it('should warn within a strict tree', async () => {
-    const {StrictMode} = React;
-
-    class OuterComponent extends React.Component {
-      render() {
-        return (
-          <StrictMode>
-            <InnerComponent ref="somestring" />
-          </StrictMode>
-        );
-      }
-    }
-
-    class InnerComponent extends React.Component {
-      render() {
-        return null;
-      }
-    }
-
-    const container = document.createElement('div');
-    const root = ReactDOMClient.createRoot(container);
-    await expect(async () => {
-      await act(() => {
-        root.render(<OuterComponent />);
-      });
-    }).toErrorDev(
-      'Component "OuterComponent" contains the string ref "somestring". ' +
-        'Support for string refs will be removed in a future major release. ' +
-        'We recommend using useRef() or createRef() instead. ' +
-        'Learn more about using refs safely here: https://react.dev/link/strict-mode-string-ref\n' +
-        '    in InnerComponent (at **)',
-    );
-
-    await act(() => {
-      root.render(<OuterComponent />);
-    });
-  });
-});
-
 describe('context legacy', () => {
   beforeEach(() => {
     jest.resetModules();
diff --git a/packages/react/src/__tests__/ReactTypeScriptClass-test.ts b/packages/react/src/__tests__/ReactTypeScriptClass-test.ts
index 4f4564d356a8..00e3a8b3ff8a 100644
--- a/packages/react/src/__tests__/ReactTypeScriptClass-test.ts
+++ b/packages/react/src/__tests__/ReactTypeScriptClass-test.ts
@@ -697,20 +697,4 @@ describe('ReactTypeScriptClass', function() {
 ]      );
     });
   }
-
-  if (!ReactFeatureFlags.disableStringRefs) {
-    it('supports string refs', function() {
-      const ref = React.createRef();
-      expect(() => {
-        test(React.createElement(ClassicRefs, {ref: ref}), 'DIV', 'foo');
-      }).toErrorDev([
-        'Component "ClassicRefs" contains the string ref "inner". ' +
-          'Support for string refs will be removed in a future major release. ' +
-          'We recommend using useRef() or createRef() instead. ' +
-          'Learn more about using refs safely here: https://react.dev/link/strict-mode-string-ref\n' +
-          '    in Inner (at **)',
-      ]);
-      expect(ref.current.refs.inner.getName()).toBe('foo');
-    });
-  }
 });
diff --git a/packages/react/src/jsx/ReactJSXElement.js b/packages/react/src/jsx/ReactJSXElement.js
index 3722638ad951..e0a689ec2404 100644
--- a/packages/react/src/jsx/ReactJSXElement.js
+++ b/packages/react/src/jsx/ReactJSXElement.js
@@ -20,13 +20,9 @@ import isValidElementType from 'shared/isValidElementType';
 import isArray from 'shared/isArray';
 import {describeUnknownElementTypeFrameInDEV} from 'shared/ReactComponentStackFrame';
 import {
-  disableStringRefs,
   disableDefaultPropsExceptForClasses,
   enableOwnerStacks,
 } from 'shared/ReactFeatureFlags';
-import {checkPropStringCoercion} from 'shared/CheckStringCoercion';
-import {ClassComponent} from 'react-reconciler/src/ReactWorkTags';
-import getComponentNameFromFiber from 'react-reconciler/src/getComponentNameFromFiber';
 
 const REACT_CLIENT_REFERENCE = Symbol.for('react.client.reference');
 
@@ -59,7 +55,7 @@ function getTaskName(type) {
 }
 
 function getOwner() {
-  if (__DEV__ || !disableStringRefs) {
+  if (__DEV__) {
     const dispatcher = ReactSharedInternals.A;
     if (dispatcher === null) {
       return null;
@@ -70,17 +66,13 @@ function getOwner() {
 }
 
 let specialPropKeyWarningShown;
-let didWarnAboutStringRefs;
 let didWarnAboutElementRef;
 let didWarnAboutOldJSXRuntime;
 
 if (__DEV__) {
-  didWarnAboutStringRefs = {};
   didWarnAboutElementRef = {};
 }
 
-const enableFastJSXWithoutStringRefs = disableStringRefs;
-
 function hasValidRef(config) {
   if (__DEV__) {
     if (hasOwnProperty.call(config, 'ref')) {
@@ -105,35 +97,6 @@ function hasValidKey(config) {
   return config.key !== undefined;
 }
 
-function warnIfStringRefCannotBeAutoConverted(config, self) {
-  if (__DEV__) {
-    let owner;
-    if (
-      !disableStringRefs &&
-      typeof config.ref === 'string' &&
-      (owner = getOwner()) &&
-      self &&
-      owner.stateNode !== self
-    ) {
-      const componentName = getComponentNameFromType(owner.type);
-
-      if (!didWarnAboutStringRefs[componentName]) {
-        console.error(
-          'Component "%s" contains the string ref "%s". ' +
-            'Support for string refs will be removed in a future major release. ' +
-            'This case cannot be automatically converted to an arrow function. ' +
-            'We ask you to manually fix this case by using useRef() or createRef() instead. ' +
-            'Learn more about using refs safely here: ' +
-            'https://react.dev/link/strict-mode-string-ref',
-          getComponentNameFromType(owner.type),
-          config.ref,
-        );
-        didWarnAboutStringRefs[componentName] = true;
-      }
-    }
-  }
-}
-
 function defineKeyPropWarningGetter(props, displayName) {
   if (__DEV__) {
     const warnAboutAccessingKey = function () {
@@ -259,22 +222,8 @@ function ReactElement(
         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
-      $$typeof: REACT_ELEMENT_TYPE,
-
-      // Built-in properties that belong on the element
-      type,
-      key,
-      ref,
-
-      props,
-    };
   } else {
-    // In prod, `ref` is a regular property. It will be removed in a
-    // future release.
+    // In prod, `ref` is a regular property and _owner doesn't exist.
     element = {
       // This tag allows us to uniquely identify this as a React Element
       $$typeof: REACT_ELEMENT_TYPE,
@@ -285,9 +234,6 @@ function ReactElement(
       ref,
 
       props,
-
-      // Record the component responsible for creating this element.
-      _owner: owner,
     };
   }
 
@@ -368,10 +314,7 @@ export function jsxProd(type, config, maybeKey) {
   }
 
   let props;
-  if (
-    (enableFastJSXWithoutStringRefs || !('ref' in config)) &&
-    !('key' in config)
-  ) {
+  if (!('key' in config)) {
     // If key was not spread in, we can reuse the original props object. This
     // only works for `jsx`, not `createElement`, because `jsx` is a compiler
     // target and the compiler always passes a new object. For `createElement`,
@@ -390,11 +333,7 @@ export function jsxProd(type, config, maybeKey) {
     for (const propName in config) {
       // Skip over reserved prop names
       if (propName !== 'key') {
-        if (!disableStringRefs && propName === 'ref') {
-          props.ref = coerceStringRef(config[propName], getOwner(), type);
-        } else {
-          props[propName] = config[propName];
-        }
+        props[propName] = config[propName];
       }
     }
   }
@@ -637,17 +576,8 @@ function jsxDEVImpl(
       key = '' + config.key;
     }
 
-    if (!disableStringRefs) {
-      if (hasValidRef(config)) {
-        warnIfStringRefCannotBeAutoConverted(config, self);
-      }
-    }
-
     let props;
-    if (
-      (enableFastJSXWithoutStringRefs || !('ref' in config)) &&
-      !('key' in config)
-    ) {
+    if (!('key' in config)) {
       // If key was not spread in, we can reuse the original props object. This
       // only works for `jsx`, not `createElement`, because `jsx` is a compiler
       // target and the compiler always passes a new object. For `createElement`,
@@ -666,11 +596,7 @@ function jsxDEVImpl(
       for (const propName in config) {
         // Skip over reserved prop names
         if (propName !== 'key') {
-          if (!disableStringRefs && propName === 'ref') {
-            props.ref = coerceStringRef(config[propName], getOwner(), type);
-          } else {
-            props[propName] = config[propName];
-          }
+          props[propName] = config[propName];
         }
       }
     }
@@ -800,11 +726,6 @@ export function createElement(type, config, children) {
       }
     }
 
-    if (__DEV__ && !disableStringRefs) {
-      if (hasValidRef(config)) {
-        warnIfStringRefCannotBeAutoConverted(config, config.__self);
-      }
-    }
     if (hasValidKey(config)) {
       if (__DEV__) {
         checkKeyStringCoercion(config.key);
@@ -825,11 +746,7 @@ export function createElement(type, config, children) {
         propName !== '__self' &&
         propName !== '__source'
       ) {
-        if (!disableStringRefs && propName === 'ref') {
-          props.ref = coerceStringRef(config[propName], getOwner(), type);
-        } else {
-          props[propName] = config[propName];
-        }
+        props[propName] = config[propName];
       }
     }
   }
@@ -889,7 +806,7 @@ export function cloneAndReplaceKey(oldElement, newKey) {
     newKey,
     undefined,
     undefined,
-    !__DEV__ && disableStringRefs ? undefined : oldElement._owner,
+    !__DEV__ ? undefined : oldElement._owner,
     oldElement.props,
     __DEV__ && enableOwnerStacks ? oldElement._debugStack : undefined,
     __DEV__ && enableOwnerStacks ? oldElement._debugTask : undefined,
@@ -921,11 +838,11 @@ export function cloneElement(element, config, children) {
   let key = element.key;
 
   // Owner will be preserved, unless ref is overridden
-  let owner = !__DEV__ && disableStringRefs ? undefined : element._owner;
+  let owner = !__DEV__ ? undefined : element._owner;
 
   if (config != null) {
     if (hasValidRef(config)) {
-      owner = __DEV__ || !disableStringRefs ? getOwner() : undefined;
+      owner = __DEV__ ? getOwner() : undefined;
     }
     if (hasValidKey(config)) {
       if (__DEV__) {
@@ -969,11 +886,7 @@ export function cloneElement(element, config, children) {
           // Resolve default props
           props[propName] = defaultProps[propName];
         } else {
-          if (!disableStringRefs && propName === 'ref') {
-            props.ref = coerceStringRef(config[propName], owner, element.type);
-          } else {
-            props[propName] = config[propName];
-          }
+          props[propName] = config[propName];
         }
       }
     }
@@ -1173,99 +1086,3 @@ function getCurrentComponentErrorInfo(parentType) {
     return info;
   }
 }
-
-function coerceStringRef(mixedRef, owner, type) {
-  if (disableStringRefs) {
-    return mixedRef;
-  }
-
-  let stringRef;
-  if (typeof mixedRef === 'string') {
-    stringRef = mixedRef;
-  } else {
-    if (typeof mixedRef === 'number' || typeof mixedRef === 'boolean') {
-      if (__DEV__) {
-        checkPropStringCoercion(mixedRef, 'ref');
-      }
-      stringRef = '' + mixedRef;
-    } else {
-      return mixedRef;
-    }
-  }
-
-  const callback = stringRefAsCallbackRef.bind(null, stringRef, type, owner);
-  // This is used to check whether two callback refs conceptually represent
-  // the same string ref, and can therefore be reused by the reconciler. Needed
-  // for backwards compatibility with old Meta code that relies on string refs
-  // not being reattached on every render.
-  callback.__stringRef = stringRef;
-  callback.__type = type;
-  callback.__owner = owner;
-  return callback;
-}
-
-function stringRefAsCallbackRef(stringRef, type, owner, value) {
-  if (disableStringRefs) {
-    return;
-  }
-  if (!owner) {
-    throw new Error(
-      `Element ref was specified as a string (${stringRef}) but no owner was set. This could happen for one of` +
-        ' the following reasons:\n' +
-        '1. You may be adding a ref to a function component\n' +
-        "2. You may be adding a ref to a component that was not created inside a component's render method\n" +
-        '3. You have multiple copies of React loaded\n' +
-        'See https://react.dev/link/refs-must-have-owner for more information.',
-    );
-  }
-  if (owner.tag !== ClassComponent) {
-    throw new Error(
-      'Function components cannot have string refs. ' +
-        'We recommend using useRef() instead. ' +
-        'Learn more about using refs safely here: ' +
-        'https://react.dev/link/strict-mode-string-ref',
-    );
-  }
-
-  if (__DEV__) {
-    if (
-      // Will already warn with "Function components cannot be given refs"
-      !(typeof type === 'function' && !isReactClass(type))
-    ) {
-      const componentName = getComponentNameFromFiber(owner) || 'Component';
-      if (!didWarnAboutStringRefs[componentName]) {
-        if (__DEV__) {
-          console.error(
-            'Component "%s" contains the string ref "%s". Support for string refs ' +
-              'will be removed in a future major release. We recommend using ' +
-              'useRef() or createRef() instead. ' +
-              'Learn more about using refs safely here: ' +
-              'https://react.dev/link/strict-mode-string-ref',
-            componentName,
-            stringRef,
-          );
-        }
-        didWarnAboutStringRefs[componentName] = true;
-      }
-    }
-  }
-
-  const inst = owner.stateNode;
-  if (!inst) {
-    throw new Error(
-      `Missing owner for string ref ${stringRef}. This error is likely caused by a ` +
-        'bug in React. Please file an issue.',
-    );
-  }
-
-  const refs = inst.refs;
-  if (value === null) {
-    delete refs[stringRef];
-  } else {
-    refs[stringRef] = value;
-  }
-}
-
-function isReactClass(type) {
-  return type.prototype && type.prototype.isReactComponent;
-}
diff --git a/packages/shared/ReactFeatureFlags.js b/packages/shared/ReactFeatureFlags.js
index d1159e60373c..44d6e8629db8 100644
--- a/packages/shared/ReactFeatureFlags.js
+++ b/packages/shared/ReactFeatureFlags.js
@@ -208,8 +208,6 @@ export const enableFilterEmptyStringAttributesDOM = true;
 // Disabled caching behavior of `react/cache` in client runtimes.
 export const disableClientCache = true;
 
-export const disableStringRefs = true;
-
 // Warn on any usage of ReactTestRenderer
 export const enableReactTestRendererWarning = true;
 
diff --git a/packages/shared/forks/ReactFeatureFlags.native-fb.js b/packages/shared/forks/ReactFeatureFlags.native-fb.js
index 7e63db5ef45e..a553c275fed8 100644
--- a/packages/shared/forks/ReactFeatureFlags.native-fb.js
+++ b/packages/shared/forks/ReactFeatureFlags.native-fb.js
@@ -41,7 +41,6 @@ export const disableLegacyContext = false;
 export const disableLegacyContextForFunctionComponents = false;
 export const disableLegacyMode = false;
 export const disableSchedulerTimeoutInWorkLoop = false;
-export const disableStringRefs = true;
 export const disableTextareaChildren = false;
 export const enableAsyncActions = true;
 export const enableAsyncDebugInfo = false;
diff --git a/packages/shared/forks/ReactFeatureFlags.native-oss.js b/packages/shared/forks/ReactFeatureFlags.native-oss.js
index 644b23b46afa..d59e3f9698d4 100644
--- a/packages/shared/forks/ReactFeatureFlags.native-oss.js
+++ b/packages/shared/forks/ReactFeatureFlags.native-oss.js
@@ -30,7 +30,6 @@ export const disableLegacyContext = true;
 export const disableLegacyContextForFunctionComponents = true;
 export const disableLegacyMode = false;
 export const disableSchedulerTimeoutInWorkLoop = false;
-export const disableStringRefs = true;
 export const disableTextareaChildren = false;
 export const enableAsyncActions = true;
 export const enableAsyncDebugInfo = false;
diff --git a/packages/shared/forks/ReactFeatureFlags.test-renderer.js b/packages/shared/forks/ReactFeatureFlags.test-renderer.js
index 2946d5efa11b..c27b2d6913dc 100644
--- a/packages/shared/forks/ReactFeatureFlags.test-renderer.js
+++ b/packages/shared/forks/ReactFeatureFlags.test-renderer.js
@@ -90,7 +90,6 @@ export const enableSiblingPrerendering = false;
 // We really need to get rid of this whole module. Any test renderer specific
 // flags should be handled by the Fiber config.
 // const __NEXT_MAJOR__ = __EXPERIMENTAL__;
-export const disableStringRefs = true;
 export const disableLegacyMode = true;
 export const disableLegacyContext = true;
 export const disableLegacyContextForFunctionComponents = true;
diff --git a/packages/shared/forks/ReactFeatureFlags.test-renderer.native-fb.js b/packages/shared/forks/ReactFeatureFlags.test-renderer.native-fb.js
index 1d505aaf56b9..170145c93db6 100644
--- a/packages/shared/forks/ReactFeatureFlags.test-renderer.native-fb.js
+++ b/packages/shared/forks/ReactFeatureFlags.test-renderer.native-fb.js
@@ -22,7 +22,6 @@ export const disableLegacyContext = false;
 export const disableLegacyContextForFunctionComponents = false;
 export const disableLegacyMode = false;
 export const disableSchedulerTimeoutInWorkLoop = false;
-export const disableStringRefs = true;
 export const disableTextareaChildren = false;
 export const enableAsyncActions = true;
 export const enableAsyncDebugInfo = false;
diff --git a/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js b/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js
index 8e9e8f0ca2d5..46e939fd7319 100644
--- a/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js
+++ b/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js
@@ -82,8 +82,6 @@ export const disableClientCache = true;
 export const enableServerComponentLogs = true;
 export const enableInfiniteRenderLoopDetection = false;
 
-export const disableStringRefs = true;
-
 export const enableReactTestRendererWarning = false;
 export const disableLegacyMode = true;
 
diff --git a/packages/shared/forks/ReactFeatureFlags.www.js b/packages/shared/forks/ReactFeatureFlags.www.js
index dac110129ef5..32a39121441b 100644
--- a/packages/shared/forks/ReactFeatureFlags.www.js
+++ b/packages/shared/forks/ReactFeatureFlags.www.js
@@ -52,7 +52,6 @@ export const enableSuspenseAvoidThisFallback = true;
 export const enableSuspenseAvoidThisFallbackFizz = false;
 
 export const disableIEWorkarounds = true;
-export const disableStringRefs = true;
 export const enableCPUSuspense = true;
 export const enableUseMemoCacheHook = true;
 export const enableUseEffectEventHook = true;