From fe3f0ec0374b7323bf259e4154eb4ee739caac7b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Markb=C3=A5ge?= <sebastian@calyptus.eu>
Date: Sun, 22 Jun 2025 10:40:56 -0400
Subject: [PATCH] [Flight] Don't use object property initializer for async
 iterable (#33591)

It turns out this was being compiled to a `_defineProperty` helper by
Babel or Closure. We're supposed to have it error the build when we use
features like this that might get compiled.

We should stick to simple ES5 features.
---
 .../react-client/src/ReactFlightClient.js     | 48 ++++++++++---------
 1 file changed, 25 insertions(+), 23 deletions(-)

diff --git a/packages/react-client/src/ReactFlightClient.js b/packages/react-client/src/ReactFlightClient.js
index ec69d8aea9..cfe82093df 100644
--- a/packages/react-client/src/ReactFlightClient.js
+++ b/packages/react-client/src/ReactFlightClient.js
@@ -2077,32 +2077,34 @@ function startAsyncIterable<T>(
       }
     },
   };
-  const iterable: $AsyncIterable<T, T, void> = {
-    [ASYNC_ITERATOR](): $AsyncIterator<T, T, void> {
-      let nextReadIndex = 0;
-      return createIterator(arg => {
-        if (arg !== undefined) {
-          throw new Error(
-            'Values cannot be passed to next() of AsyncIterables passed to Client Components.',
+
+  const iterable: $AsyncIterable<T, T, void> = ({}: any);
+  // $FlowFixMe[cannot-write]
+  iterable[ASYNC_ITERATOR] = (): $AsyncIterator<T, T, void> => {
+    let nextReadIndex = 0;
+    return createIterator(arg => {
+      if (arg !== undefined) {
+        throw new Error(
+          'Values cannot be passed to next() of AsyncIterables passed to Client Components.',
+        );
+      }
+      if (nextReadIndex === buffer.length) {
+        if (closed) {
+          // $FlowFixMe[invalid-constructor] Flow doesn't support functions as constructors
+          return new ReactPromise(
+            INITIALIZED,
+            {done: true, value: undefined},
+            null,
+            response,
           );
         }
-        if (nextReadIndex === buffer.length) {
-          if (closed) {
-            // $FlowFixMe[invalid-constructor] Flow doesn't support functions as constructors
-            return new ReactPromise(
-              INITIALIZED,
-              {done: true, value: undefined},
-              null,
-              response,
-            );
-          }
-          buffer[nextReadIndex] =
-            createPendingChunk<IteratorResult<T, T>>(response);
-        }
-        return buffer[nextReadIndex++];
-      });
-    },
+        buffer[nextReadIndex] =
+          createPendingChunk<IteratorResult<T, T>>(response);
+      }
+      return buffer[nextReadIndex++];
+    });
   };
+
   // TODO: If it's a single shot iterator we can optimize memory by cleaning up the buffer after
   // reading through the end, but currently we favor code size over this optimization.
   resolveStream(