From 45ed204abe8ca59e1753c2fead75898908f031cf Mon Sep 17 00:00:00 2001
From: Scott Cooper <scttcper@gmail.com>
Date: Mon, 24 Aug 2026 10:12:59 -0700
Subject: [PATCH] perf(react-form): Use one subscription per Field

Each React Field subscribed to the same atom once for value and again for meta. The field atom already preserves state identity when neither changes, so one whole-state subscription has the same render behavior.

Co-Authored-By: OpenAI Codex <noreply@openai.com>
---
 .../react-form/src/ReactForm/fieldSubscriptions.lib.ts    | 8 +++-----
 packages/react-form/tests/FormGroup.spec.tsx              | 4 ++--
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/packages/react-form/src/ReactForm/fieldSubscriptions.lib.ts b/packages/react-form/src/ReactForm/fieldSubscriptions.lib.ts
index 760b3575e1..8c9f120da4 100644
--- a/packages/react-form/src/ReactForm/fieldSubscriptions.lib.ts
+++ b/packages/react-form/src/ReactForm/fieldSubscriptions.lib.ts
@@ -5,14 +5,12 @@ import type { AnyInternalFieldApi } from '@tanstack/form-core/internals'
 export function useValueFieldSubscription(
   fieldApi: AnyInternalFieldApi,
 ): AnyInternalFieldApi {
-  const value = useSelector(fieldApi.atom, (state) => state.value)
-  const meta = useSelector(fieldApi.atom, (state) => state.meta)
+  const state = useSelector(fieldApi.atom)
 
   return useMemo(() => {
-    void meta
-    void value
+    void state
     return Object.create(fieldApi)
-  }, [fieldApi, meta, value])
+  }, [fieldApi, state])
 }
 
 export function useArrayFieldSubscription(
diff --git a/packages/react-form/tests/FormGroup.spec.tsx b/packages/react-form/tests/FormGroup.spec.tsx
index c040db8d9e..62dd054c29 100644
--- a/packages/react-form/tests/FormGroup.spec.tsx
+++ b/packages/react-form/tests/FormGroup.spec.tsx
@@ -118,7 +118,7 @@ describe('FormGroup', () => {
     expect(getByTestId('app-field-name')).toHaveTextContent('guestDetails.name')
   })
 
-  it('uses the AppForm field provider subscription for field context', async () => {
+  it('uses one AppForm field provider subscription for field context', async () => {
     const subscribe = vi.fn()
     const unsubscribe = vi.fn()
     const instrumentedAtoms = new WeakSet<object>()
@@ -169,7 +169,7 @@ describe('FormGroup', () => {
 
     await vi.waitFor(() => {
       expect(subscribe.mock.calls.length - unsubscribe.mock.calls.length).toBe(
-        2,
+        1,
       )
     })