From d6a7af9e306aca34c88e899dc596df811e09bf09 Mon Sep 17 00:00:00 2001
From: Mishra-coder <devendramishra495@gmail.com>
Date: Fri, 27 Mar 2026 00:14:59 +0530
Subject: [PATCH 1/2] fix: prevent initialFormState from overriding client
 state

Closes #2089
---
 packages/react-form-nextjs/src/createServerValidate.ts | 3 +--
 packages/react-form-remix/src/createServerValidate.ts  | 3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/packages/react-form-nextjs/src/createServerValidate.ts b/packages/react-form-nextjs/src/createServerValidate.ts
index b936f1e8e..41ddc4cb7 100644
--- a/packages/react-form-nextjs/src/createServerValidate.ts
+++ b/packages/react-form-nextjs/src/createServerValidate.ts
@@ -133,6 +133,5 @@ export const initialFormState: ServerFormState<any, undefined> = {
   errorMap: {
     onServer: undefined,
   },
-  values: undefined,
   errors: [],
-}
+} as unknown as ServerFormState<any, undefined>
diff --git a/packages/react-form-remix/src/createServerValidate.ts b/packages/react-form-remix/src/createServerValidate.ts
index b936f1e8e..41ddc4cb7 100644
--- a/packages/react-form-remix/src/createServerValidate.ts
+++ b/packages/react-form-remix/src/createServerValidate.ts
@@ -133,6 +133,5 @@ export const initialFormState: ServerFormState<any, undefined> = {
   errorMap: {
     onServer: undefined,
   },
-  values: undefined,
   errors: [],
-}
+} as unknown as ServerFormState<any, undefined>

From 4d8e0abf2740fea8c6a2245479a4845a8ab8abb7 Mon Sep 17 00:00:00 2001
From: Mishra-coder <devendramishra495@gmail.com>
Date: Mon, 30 Mar 2026 00:13:01 +0530
Subject: [PATCH 2/2] test: add regression tests for initialFormState override
 fix

---
 .../tests/createServerValidate.spec.tsx       | 22 +++++++++++++++++++
 .../tests/createServerValidate.spec.tsx       | 22 +++++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 packages/react-form-nextjs/tests/createServerValidate.spec.tsx
 create mode 100644 packages/react-form-remix/tests/createServerValidate.spec.tsx

diff --git a/packages/react-form-nextjs/tests/createServerValidate.spec.tsx b/packages/react-form-nextjs/tests/createServerValidate.spec.tsx
new file mode 100644
index 000000000..a26db617c
--- /dev/null
+++ b/packages/react-form-nextjs/tests/createServerValidate.spec.tsx
@@ -0,0 +1,22 @@
+import { describe, expect, it } from 'vitest'
+import { mutateMergeDeep } from '@tanstack/react-form'
+import { initialFormState } from '../src/createServerValidate'
+
+describe('initialFormState', () => {
+  it('should not contain values property', () => {
+    expect(initialFormState).not.toHaveProperty('values')
+  })
+
+  it('should not override client values when merged', () => {
+    const clientState = {
+      values: { name: 'client-name' },
+      errors: [],
+      errorMap: {}
+    }
+
+    // @ts-ignore
+    mutateMergeDeep(clientState, initialFormState)
+
+    expect(clientState.values).toEqual({ name: 'client-name' })
+  })
+})
diff --git a/packages/react-form-remix/tests/createServerValidate.spec.tsx b/packages/react-form-remix/tests/createServerValidate.spec.tsx
new file mode 100644
index 000000000..a26db617c
--- /dev/null
+++ b/packages/react-form-remix/tests/createServerValidate.spec.tsx
@@ -0,0 +1,22 @@
+import { describe, expect, it } from 'vitest'
+import { mutateMergeDeep } from '@tanstack/react-form'
+import { initialFormState } from '../src/createServerValidate'
+
+describe('initialFormState', () => {
+  it('should not contain values property', () => {
+    expect(initialFormState).not.toHaveProperty('values')
+  })
+
+  it('should not override client values when merged', () => {
+    const clientState = {
+      values: { name: 'client-name' },
+      errors: [],
+      errorMap: {}
+    }
+
+    // @ts-ignore
+    mutateMergeDeep(clientState, initialFormState)
+
+    expect(clientState.values).toEqual({ name: 'client-name' })
+  })
+})