chore: migrate to useCustomFieldValue (#9201)

src/utils/constant.ts

@@ -1,4 +1,6 @@
-// border
+import type { InjectionKey } from 'vue';
+import type { FormProvide } from '../form/types';
+
 export const BORDER = 'van-hairline';
 export const BORDER_TOP = `${BORDER}--top`;
 export const BORDER_LEFT = `${BORDER}--left`;
@@ -6,3 +8,5 @@ export const BORDER_BOTTOM = `${BORDER}--bottom`;
 export const BORDER_SURROUND = `${BORDER}--surround`;
 export const BORDER_TOP_BOTTOM = `${BORDER}--top-bottom`;
 export const BORDER_UNSET_TOP_BOTTOM = `${BORDER}-unset--top-bottom`;
+
+export const FORM_KEY: InjectionKey<FormProvide> = Symbol('van-form');

src/utils/index.ts

@@ -1,10 +1,12 @@
 export * from './base';
 export * from './create';
+export * from './constant';
 export * from './validate';
+export * from './dom/style';
+export * from './dom/event';
+export * from './dom/scroll';
+export * from './interceptor';
 export * from './with-install';
 export * from './format/unit';
 export * from './format/number';
 export * from './format/string';
-export * from './dom/style';
-export * from './dom/event';
-export * from './dom/scroll';