From 428390dfa26349130ac75bc6d708449f8f29a349 Mon Sep 17 00:00:00 2001
From: Ray <hello@ramonclaudio.com>
Date: Thu, 7 May 2026 19:07:36 -0400
Subject: [PATCH] fix(react): wrap fetchAccessToken in new Promise to fix
 useConvexAuth on Hermes V1

The /convex/token response triggers a session rotation (via Better
Auth's Set-Cookie processing) plus a setCachedToken call inside the
bridge's .then. The next render rebuilds fetchAccessToken's
useCallback (keyed on [sessionId]) and fires
ConvexAuthStateFirstEffect's client.setAuth a second time.

On Hermes V1 native async (Expo SDK 56 canary 2026-05-05+ since
expo/expo#45345 dropped @babel/plugin-transform-async-to-generator),
that second setAuth lands inside the first setConfig's await window
in authentication_manager.ts. fetchTokenAndGuardAgainstRace bumps
configVersion on entry and the original await sees the stale value,
returning isFromOutdatedConfig: true. setConfig bails without
resumeSocket() and the chain repeats.

Drop the async keyword and wrap the body in new Promise(executor)
directly. The constructor's resolve(thenable) schedules a
NewPromiseResolveThenableJob microtask, the same hop regenerator's
_asyncToGenerator provides. With the hop in place the second setAuth
lands after the first setConfig finishes rather than during its
await window.
---
 src/react/index.tsx | 48 ++++++++++++++++++++++++---------------------
 1 file changed, 26 insertions(+), 22 deletions(-)

diff --git a/src/react/index.tsx b/src/react/index.tsx
index dc10909a..2f906878 100644
--- a/src/react/index.tsx
+++ b/src/react/index.tsx
@@ -127,30 +127,34 @@ function useUseAuthFromBetterAuth(
           }
         }, [session, isSessionPending]);
         const fetchAccessToken = useCallback(
-          async ({
+          ({
             forceRefreshToken = false,
           }: { forceRefreshToken?: boolean } = {}) => {
-            if (cachedToken && !forceRefreshToken) {
-              return cachedToken;
-            }
-            if (!forceRefreshToken && pendingTokenRef.current) {
-              return pendingTokenRef.current;
-            }
-            pendingTokenRef.current = authClient.convex
-              .token({ fetchOptions: { throw: false } })
-              .then(({ data }) => {
-                const token = data?.token || null;
-                setCachedToken(token);
-                return token;
-              })
-              .catch(() => {
-                setCachedToken(null);
-                return null;
-              })
-              .finally(() => {
-                pendingTokenRef.current = null;
-              });
-            return pendingTokenRef.current;
+            return new Promise<string | null>((resolve, reject) => {
+              if (cachedToken && !forceRefreshToken) {
+                resolve(cachedToken);
+                return;
+              }
+              if (!forceRefreshToken && pendingTokenRef.current) {
+                pendingTokenRef.current.then(resolve, reject);
+                return;
+              }
+              pendingTokenRef.current = authClient.convex
+                .token({ fetchOptions: { throw: false } })
+                .then(({ data }) => {
+                  const token = data?.token || null;
+                  setCachedToken(token);
+                  return token;
+                })
+                .catch(() => {
+                  setCachedToken(null);
+                  return null;
+                })
+                .finally(() => {
+                  pendingTokenRef.current = null;
+                });
+              pendingTokenRef.current.then(resolve, reject);
+            });
           },
           // Build a new fetchAccessToken to trigger setAuth() whenever the
           // session changes.