feat: add array fields move method (#647)

Author: t-rosa

docs/framework/react/guides/basic-concepts.md

@@ -194,7 +194,7 @@ Example:
 
 Array fields allow you to manage a list of values within a form, such as a list of hobbies. You can create an array field using the `form.Field` component with the `mode="array"` prop.
 
-When working with array fields, you can use the fields `pushValue`, `removeValue`, and `swapValues` methods to add, remove, and swap values in the array.
+When working with array fields, you can use the fields `pushValue`, `removeValue`, `swapValues` and `moveValue` methods to add, remove, and swap values in the array.
 
 Example:
 

packages/form-core/src/FieldApi.ts

@@ -482,6 +482,9 @@ export class FieldApi<
   swapValues = (aIndex: number, bIndex: number) =>
     this.form.swapFieldValues(this.name, aIndex, bIndex)
 
+  moveValue = (aIndex: number, bIndex: number) =>
+    this.form.moveFieldValues(this.name, aIndex, bIndex)
+
   validateSync = (value = this.state.value, cause: ValidationCause) => {
     const validates = getSyncValidatorArray(cause, this.options)
 

packages/form-core/src/FormApi.ts

@@ -718,6 +718,17 @@ export class FormApi<
       return setBy(setBy(prev, `${index1}`, prev2), `${index2}`, prev1)
     })
   }
+
+  moveFieldValues = <TField extends DeepKeys<TFormData>>(
+    field: TField,
+    index1: number,
+    index2: number,
+  ) => {
+    this.setFieldValue(field, (prev: any) => {
+      prev.splice(index2, 0, prev.splice(index1, 1)[0])
+      return prev
+    })
+  }
 }
 
 function normalizeError(rawError?: ValidationError) {

packages/form-core/src/tests/FieldApi.spec.ts

@@ -158,6 +158,23 @@ describe('field api', () => {
     expect(field.getValue()).toStrictEqual(['two', 'one'])
   })
 
+  it('should move a value from an array value correctly', () => {
+    const form = new FormApi({
+      defaultValues: {
+        names: ['one', 'two', 'three', 'four'],
+      },
+    })
+
+    const field = new FieldApi({
+      form,
+      name: 'names',
+    })
+
+    field.moveValue(2, 0)
+
+    expect(field.getValue()).toStrictEqual(['three', 'one', 'two', 'four'])
+  })
+
   it('should not throw errors when no meta info is stored on a field and a form re-renders', async () => {
     const form = new FormApi({
       defaultValues: {