feat(useWatch): notify watch in preserve mode

docs/examples/useWatch.tsx

@@ -13,6 +13,7 @@ type FieldType = {
   demo2?: string;
   id?: number;
   demo1?: { demo2?: { demo3?: { demo4?: string } } };
+  hidden?: string;
 };
 
 const Demo = React.memo(() => {
@@ -48,12 +49,13 @@ export default () => {
   const demo4 = Form.useWatch(['demo1', 'demo2', 'demo3', 'demo4'], form);
   const demo5 = Form.useWatch(['demo1', 'demo2', 'demo3', 'demo4', 'demo5'], form);
   const more = Form.useWatch(['age', 'name', 'gender'], form);
-  console.log('main watch', values, demo1, demo2, main, age, demo3, demo4, demo5, more);
+  const hidden = Form.useWatch(['hidden'], { form, preserve: true });
+  console.log('main watch', values, demo1, demo2, main, age, demo3, demo4, demo5, more, hidden);
   return (
     <>
       <Form
         form={form}
-        initialValues={{ id: 1, age: '10', name: 'default' }}
+        initialValues={{ id: 1, age: '10', name: 'default', hidden: 'here' }}
         onFinish={v => console.log('submit values', v)}
       >
         no render
@@ -115,6 +117,7 @@ export default () => {
       <button onClick={() => setVisible(c => !c)}>isShow name</button>
       <button onClick={() => setVisible3(c => !c)}>isShow initialValue</button>
       <button onClick={() => setVisible2(c => !c)}>isShow demo2</button>
+      <button onClick={() => form.setFieldsValue({ hidden: `${form.getFieldsValue(true).hidden || ''}1` })}>change hidden field</button>
     </>
   );
 };

src/interface.ts

@@ -193,7 +193,16 @@ export interface Callbacks<Values = any> {
   onFinishFailed?: (errorInfo: ValidateErrorEntity<Values>) => void;
 }
 
-export type WatchCallBack = (values: Store, namePathList: InternalNamePath[]) => void;
+export type WatchCallBack = (
+  values: Store,
+  allValues: Store,
+  namePathList: InternalNamePath[],
+) => void;
+
+export interface WatchOptions<Form extends FormInstance = FormInstance> {
+  form?: Form;
+  preserve?: boolean;
+}
 
 export interface InternalHooks {
   dispatch: (action: ReducerAction) => void;

src/useForm.ts

@@ -200,9 +200,10 @@ export class FormStore {
     // No need to cost perf when nothing need to watch
     if (this.watchList.length) {
       const values = this.getFieldsValue();
+      const allValues = this.getFieldsValue(true);
 
       this.watchList.forEach(callback => {
-        callback(values, namePath);
+        callback(values, allValues, namePath);
       });
     }
   };
@@ -548,7 +549,7 @@ export class FormStore {
     const namePathList: InternalNamePath[] = [];
 
     fields.forEach((fieldData: FieldData) => {
-      const { name, errors, ...data } = fieldData;
+      const { name, ...data } = fieldData;
       const namePath = getNamePath(name);
       namePathList.push(namePath);
 

src/useWatch.ts

@@ -2,9 +2,16 @@ import type { FormInstance } from '.';
 import { FieldContext } from '.';
 import warning from 'rc-util/lib/warning';
 import { HOOK_MARK } from './FieldContext';
-import type { InternalFormInstance, InternalNamePath, NamePath, Store } from './interface';
+import type {
+  InternalFormInstance,
+  InternalNamePath,
+  NamePath,
+  Store,
+  WatchOptions,
+} from './interface';
 import { useState, useContext, useEffect, useRef, useMemo } from 'react';
 import { getNamePath, getValue } from './utils/valueUtil';
+import { isFormInstance } from './utils/typeUtil';
 
 type ReturnPromise<T> = T extends Promise<infer ValueType> ? ValueType : never;
 type GetGeneric<TForm extends FormInstance> = ReturnPromise<ReturnType<TForm['validateFields']>>;
@@ -38,7 +45,7 @@ function useWatch<
   TDependencies4 extends keyof GetGeneric<TForm>[TDependencies1][TDependencies2][TDependencies3],
 >(
   dependencies: [TDependencies1, TDependencies2, TDependencies3, TDependencies4],
-  form?: TForm,
+  form?: TForm | WatchOptions<TForm>,
 ): GetGeneric<TForm>[TDependencies1][TDependencies2][TDependencies3][TDependencies4];
 
 function useWatch<
@@ -48,7 +55,7 @@ function useWatch<
   TDependencies3 extends keyof GetGeneric<TForm>[TDependencies1][TDependencies2],
 >(
   dependencies: [TDependencies1, TDependencies2, TDependencies3],
-  form?: TForm,
+  form?: TForm | WatchOptions<TForm>,
 ): GetGeneric<TForm>[TDependencies1][TDependencies2][TDependencies3];
 
 function useWatch<
@@ -57,22 +64,34 @@ function useWatch<
   TDependencies2 extends keyof GetGeneric<TForm>[TDependencies1],
 >(
   dependencies: [TDependencies1, TDependencies2],
-  form?: TForm,
+  form?: TForm | WatchOptions<TForm>,
 ): GetGeneric<TForm>[TDependencies1][TDependencies2];
 
 function useWatch<TDependencies extends keyof GetGeneric<TForm>, TForm extends FormInstance>(
   dependencies: TDependencies | [TDependencies],
-  form?: TForm,
+  form?: TForm | WatchOptions<TForm>,
 ): GetGeneric<TForm>[TDependencies];
 
-function useWatch<TForm extends FormInstance>(dependencies: [], form?: TForm): GetGeneric<TForm>;
+function useWatch<TForm extends FormInstance>(
+  dependencies: [],
+  form?: TForm | WatchOptions<TForm>,
+): GetGeneric<TForm>;
 
-function useWatch<TForm extends FormInstance>(dependencies: NamePath, form?: TForm): any;
+function useWatch<TForm extends FormInstance>(
+  dependencies: NamePath,
+  form?: TForm | WatchOptions<TForm>,
+): any;
 
-function useWatch<ValueType = Store>(dependencies: NamePath, form?: FormInstance): ValueType;
+function useWatch<ValueType = Store>(
+  dependencies: NamePath,
+  form?: FormInstance | WatchOptions<FormInstance>,
+): ValueType;
+
+function useWatch(...args: [NamePath, FormInstance | WatchOptions<FormInstance>]) {
+  const [dependencies = [], _form = {}] = args;
+  const options = isFormInstance(_form) ? { form: _form } : _form;
+  const form = options.form;
 
-function useWatch(...args: [NamePath, FormInstance]) {
-  const [dependencies = [], form] = args;
   const [value, setValue] = useState<any>();
 
   const valueStr = useMemo(() => stringify(value), [value]);
@@ -107,8 +126,8 @@ function useWatch(...args: [NamePath, FormInstance]) {
       const { getFieldsValue, getInternalHooks } = formInstance;
       const { registerWatch } = getInternalHooks(HOOK_MARK);
 
-      const cancelRegister = registerWatch(store => {
-        const newValue = getValue(store, namePathRef.current);
+      const cancelRegister = registerWatch((values, allValues) => {
+        const newValue = getValue(options.preserve ? allValues : values, namePathRef.current);
         const nextValueStr = stringify(newValue);
 
         // Compare stringify in case it's nest object
@@ -119,7 +138,10 @@ function useWatch(...args: [NamePath, FormInstance]) {
       });
 
       // TODO: We can improve this perf in future
-      const initialValue = getValue(getFieldsValue(), namePathRef.current);
+      const initialValue = getValue(
+        options.preserve ? getFieldsValue(true) : getFieldsValue(),
+        namePathRef.current,
+      );
       setValue(initialValue);
 
       return cancelRegister;

src/utils/typeUtil.ts

@@ -1,7 +1,13 @@
+import type { FormInstance, InternalFormInstance } from '../interface';
+
 export function toArray<T>(value?: T | T[] | null): T[] {
   if (value === undefined || value === null) {
     return [];
   }
 
   return Array.isArray(value) ? value : [value];
 }
+
+export function isFormInstance<T>(form: T | FormInstance): form is FormInstance {
+  return form && !!(form as InternalFormInstance)._init;
+}

tests/useWatch.test.tsx

@@ -407,4 +407,34 @@ describe('useWatch', () => {
     );
     errorSpy.mockRestore();
   });
+
+  it('useWatch with preserve option', async () => {
+    const logSpy = jest.spyOn(console, 'log').mockImplementation(() => {});
+    const Demo: React.FC = () => {
+      const [form] = Form.useForm();
+      const nameValuePreserve = Form.useWatch<string>('name', {
+        form,
+        preserve: true,
+      });
+      const nameValue = Form.useWatch<string>('name', form);
+      React.useEffect(() => {
+        console.log(nameValuePreserve, nameValue);
+      }, [nameValuePreserve, nameValue]);
+      return (
+        <div>
+          <Form form={form} initialValues={{ name: 'bamboo' }} />
+          <div className="values">{nameValuePreserve}</div>
+          <button className="test-btn" onClick={() => form.setFieldValue('name', 'light')} />
+        </div>
+      );
+    };
+    await act(async () => {
+      const { container } = render(<Demo />);
+      await timeout();
+      expect(logSpy).toHaveBeenCalledWith('bamboo', undefined); // initialValue
+      fireEvent.click(container.querySelector('.test-btn'));
+      await timeout();
+      expect(logSpy).toHaveBeenCalledWith('light', undefined); // after setFieldValue
+    });
+  });
 });