[Flight] Allow a Server Reference to be registered twice

packages/react-server-dom-esm/src/ReactFlightESMReferences.js

@@ -70,8 +70,8 @@ export function registerServerReference<T>(
 ): ServerReference<T> {
   return Object.defineProperties((reference: any), {
     $$typeof: {value: SERVER_REFERENCE_TAG},
-    $$id: {value: id + '#' + exportName},
-    $$bound: {value: null},
-    bind: {value: bind},
+    $$id: {value: id + '#' + exportName, configurable: true},
+    $$bound: {value: null, configurable: true},
+    bind: {value: bind, configurable: true},
   });
 }

packages/react-server-dom-turbopack/src/ReactFlightTurbopackReferences.js

@@ -83,9 +83,12 @@ export function registerServerReference<T>(
 ): ServerReference<T> {
   return Object.defineProperties((reference: any), {
     $$typeof: {value: SERVER_REFERENCE_TAG},
-    $$id: {value: exportName === null ? id : id + '#' + exportName},
-    $$bound: {value: null},
-    bind: {value: bind},
+    $$id: {
+      value: exportName === null ? id : id + '#' + exportName,
+      configurable: true,
+    },
+    $$bound: {value: null, configurable: true},
+    bind: {value: bind, configurable: true},
   });
 }
 

packages/react-server-dom-webpack/src/ReactFlightWebpackReferences.js

@@ -83,9 +83,12 @@ export function registerServerReference<T>(
 ): ServerReference<T> {
   return Object.defineProperties((reference: any), {
     $$typeof: {value: SERVER_REFERENCE_TAG},
-    $$id: {value: exportName === null ? id : id + '#' + exportName},
-    $$bound: {value: null},
-    bind: {value: bind},
+    $$id: {
+      value: exportName === null ? id : id + '#' + exportName,
+      configurable: true,
+    },
+    $$bound: {value: null, configurable: true},
+    bind: {value: bind, configurable: true},
   });
 }
 

packages/react-server-dom-webpack/src/__tests__/ReactFlightDOMBrowser-test.js

@@ -1078,6 +1078,58 @@ describe('ReactFlightDOMBrowser', () => {
     }
   });
 
+  it('can use the same function twice as a server action', async () => {
+    let actionProxy1;
+    let actionProxy2;
+
+    function Client({action1, action2}) {
+      actionProxy1 = action1;
+      actionProxy2 = action2;
+      return 'Click Me';
+    }
+
+    function greet(text) {
+      return 'Hello ' + text;
+    }
+
+    const ServerModule = serverExports({
+      greet,
+      greet2: greet,
+    });
+    const ClientRef = clientExports(Client);
+
+    const stream = ReactServerDOMServer.renderToReadableStream(
+      <ClientRef action1={ServerModule.greet} action2={ServerModule.greet2} />,
+      webpackMap,
+    );
+
+    const response = ReactServerDOMClient.createFromReadableStream(stream, {
+      async callServer(ref, args) {
+        const body = await ReactServerDOMClient.encodeReply(args);
+        return callServer(ref, body);
+      },
+    });
+
+    function App() {
+      return use(response);
+    }
+
+    const container = document.createElement('div');
+    const root = ReactDOMClient.createRoot(container);
+    await act(() => {
+      root.render(<App />);
+    });
+    expect(container.innerHTML).toBe('Click Me');
+    expect(typeof actionProxy1).toBe('function');
+    expect(actionProxy1).not.toBe(greet);
+
+    // TODO: Ideally flight would be encoding this the same.
+    expect(actionProxy1).not.toBe(actionProxy2);
+
+    const result = await actionProxy1('world');
+    expect(result).toBe('Hello world');
+  });
+
   it('supports Float hints before the first await in server components in Fiber', async () => {
     function Component() {
       return <p>hello world</p>;