From a0534b5aab42a96a6f2e9fee9898e11f7a9b2cff Mon Sep 17 00:00:00 2001
From: Harry Whorlow <harry.whorlow@technoly.com>
Date: Fri, 22 Nov 2024 19:32:18 +0100
Subject: [PATCH] fix(core): stop onChange triggering onMount and add tests to
 assert this

---
 packages/form-core/src/FieldApi.ts        | 11 ++++++-----
 packages/form-core/tests/FieldApi.spec.ts | 23 +++++++++++++++++++++++
 2 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/packages/form-core/src/FieldApi.ts b/packages/form-core/src/FieldApi.ts
index c9c076e05..49a72d235 100644
--- a/packages/form-core/src/FieldApi.ts
+++ b/packages/form-core/src/FieldApi.ts
@@ -551,11 +551,6 @@ export class FieldApi<
 
           this.prevState = state
           this.state = state
-
-          this.options.listeners?.onChange?.({
-            value: state.value,
-            fieldApi: this,
-          })
         },
       },
     )
@@ -701,6 +696,12 @@ export class FieldApi<
    */
   setValue = (updater: Updater<TData>, options?: UpdateMetaOptions) => {
     this.form.setFieldValue(this.name, updater as never, options)
+
+    this.options.listeners?.onChange?.({
+      value: updater as never,
+      fieldApi: this,
+    })
+
     this.validate('change')
   }
 
diff --git a/packages/form-core/tests/FieldApi.spec.ts b/packages/form-core/tests/FieldApi.spec.ts
index 6ce17b716..a250bcc29 100644
--- a/packages/form-core/tests/FieldApi.spec.ts
+++ b/packages/form-core/tests/FieldApi.spec.ts
@@ -956,6 +956,29 @@ describe('field api', () => {
     expect(triggered).toStrictEqual('other')
   })
 
+  it('should not run the listener onChange on mount', () => {
+    const form = new FormApi({
+      defaultValues: {
+        name: 'test',
+      },
+    })
+
+    let triggered!: string
+    const field = new FieldApi({
+      form,
+      name: 'name',
+      listeners: {
+        onChange: ({ value }) => {
+          triggered = value
+        },
+      },
+    })
+
+    field.mount()
+
+    expect(triggered).toStrictEqual(undefined)
+  })
+
   it('should run listener onBlur', () => {
     const form = new FormApi({
       defaultValues: {