[Flight Reply] Don't allow Symbols to be passed to a reply

packages/react-client/src/ReactFlightReplyClient.js

@@ -105,10 +105,6 @@ function serializeTemporaryReferenceID(id: number): string {
   return '$T' + id.toString(16);
 }
 
-function serializeSymbolReference(name: string): string {
-  return '$S' + name;
-}
-
 function serializeFormDataReference(id: number): string {
   // Why K? F is "Function". D is "Date". What else?
   return '$K' + id.toString(16);
@@ -479,18 +475,16 @@ export function processReply(
     }
 
     if (typeof value === 'symbol') {
-      // $FlowFixMe[incompatible-type] `description` might be undefined
-      const name: string = value.description;
-      if (Symbol.for(name) !== value) {
+      if (temporaryReferences === undefined) {
         throw new Error(
-          'Only global symbols received from Symbol.for(...) can be passed to Server Functions. ' +
-            `The symbol Symbol.for(${
-              // $FlowFixMe[incompatible-type] `description` might be undefined
-              value.description
-            }) cannot be found among global symbols.`,
+          'Symbols cannot be passed to a Server Function without a ' +
+            'temporary reference set. Pass a TemporaryReferenceSet to the options.' +
+            (__DEV__ ? describeObjectForErrorMessage(parent, key) : ''),
         );
       }
-      return serializeSymbolReference(name);
+      return serializeTemporaryReferenceID(
+        writeTemporaryReference(temporaryReferences, value),
+      );
     }
 
     if (typeof value === 'bigint') {

packages/react-client/src/ReactFlightTemporaryReferences.js

@@ -9,15 +9,15 @@
 
 interface Reference {}
 
-export opaque type TemporaryReferenceSet = Array<Reference>;
+export opaque type TemporaryReferenceSet = Array<Reference | symbol>;
 
 export function createTemporaryReferenceSet(): TemporaryReferenceSet {
   return [];
 }
 
 export function writeTemporaryReference(
   set: TemporaryReferenceSet,
-  object: Reference,
+  object: Reference | symbol,
 ): number {
   // We always create a new entry regardless if we've already written the same
   // object. This ensures that we always generate a deterministic encoding of
@@ -27,15 +27,15 @@ export function writeTemporaryReference(
   return newId;
 }
 
-export function readTemporaryReference(
+export function readTemporaryReference<T>(
   set: TemporaryReferenceSet,
   id: number,
-): Reference {
+): T {
   if (id < 0 || id >= set.length) {
     throw new Error(
       "The RSC response contained a reference that doesn't exist in the temporary reference set. " +
         'Always pass the matching set that was used to create the reply when parsing its response.',
     );
   }
-  return set[id];
+  return (set[id]: any);
 }

packages/react-server/src/ReactFlightReplyServer.js

@@ -396,10 +396,6 @@ function parseModelString(
         const chunk = getChunk(response, id);
         return chunk;
       }
-      case 'S': {
-        // Symbol
-        return Symbol.for(value.slice(2));
-      }
       case 'F': {
         // Server Reference
         const id = parseInt(value.slice(2), 16);

scripts/error-codes/codes.json

@@ -501,5 +501,6 @@
   "513": "Cannot render a Client Context Provider on the Server. Instead, you can export a Client Component wrapper that itself renders a Client Context Provider.",
   "514": "Cannot access %s on the server. You cannot dot into a temporary client reference from a server component. You can only pass the value through to the client.",
   "515": "Cannot assign to a temporary client reference from a server module.",
-  "516": "Attempted to call a temporary Client Reference from the server but it is on the client. It's not possible to invoke a client function from the server, it can only be rendered as a Component or passed to props of a Client Component."
+  "516": "Attempted to call a temporary Client Reference from the server but it is on the client. It's not possible to invoke a client function from the server, it can only be rendered as a Component or passed to props of a Client Component.",
+  "517": "Symbols cannot be passed to a Server Function without a temporary reference set. Pass a TemporaryReferenceSet to the options.%s"
 }