import React from 'react'; import { fireEvent, render, renderHook, screen, waitFor, within, } from '@testing-library/react'; import { Controller } from '../controller'; import type { Control, UseFieldArrayReturn, UseFormRegister, UseFormReturn, } from '../types'; import { useController } from '../useController'; import { useFieldArray } from '../useFieldArray'; import { useForm } from '../useForm'; import { FormProvider, useFormContext } from '../useFormContext'; import { useWatch } from '../useWatch'; import noop from '../utils/noop'; let i = 0; jest.mock('../logic/generateId', () => () => String(i++)); describe('useWatch', () => { beforeEach(() => { i = 0; }); it('should return default value in useForm', () => { let method; let watched; const Component = () => { method = useForm<{ test: string }>({ defaultValues: { test: 'test' } }); watched = useWatch({ control: method.control }); return
; }; render(); expect(watched).toEqual({ test: 'test' }); }); it('should return default value in useWatch', () => { const { result } = renderHook(() => { const { control } = useForm<{ test: string }>({ defaultValues: { test: 'test', }, }); return useWatch({ control, name: 'test', }); }); expect(result.current).toEqual('test'); }); it('should return default value for single input', () => { const { result } = renderHook(() => { const { control } = useForm<{ test: string; test1: string }>({ defaultValues: { test: 'test', test1: 'test1', }, }); return useWatch({ control, name: 'test', }); }); expect(result.current).toEqual('test'); }); it('should return default values for array of inputs', () => { const { result } = renderHook(() => { const { control } = useForm<{ test: string; test1: string }>({ defaultValues: { test: 'test', test1: 'test1', }, }); return useWatch({ control, name: ['test', 'test1'], }); }); expect(result.current).toEqual(['test', 'test1']); }); it('should return own default value for single input', () => { const { result } = renderHook(() => { const { control } = useForm<{ test: string; test1: string }>({}); return useWatch({ control, name: 'test', defaultValue: 'test', }); }); expect(result.current).toEqual('test'); }); it('should return own default value for array of inputs', () => { const { result } = renderHook(() => { const { control } = useForm<{ test: string; test1: string }>({}); return useWatch({ control, name: ['test', 'test1'], defaultValue: { test: 'test', test1: 'test1', }, }); }); expect(result.current).toEqual(['test', 'test1']); }); it('should return default value when name is undefined', () => { const { result } = renderHook(() => { const { control } = useForm<{ test: string; test1: string }>({ defaultValues: { test: 'test', test1: 'test1', }, }); return useWatch({ control, }); }); expect(result.current).toEqual({ test: 'test', test1: 'test1' }); }); it('should return empty array when watch array fields', () => { const { result } = renderHook(() => { const { control } = useForm<{ test: string }>(); return useWatch({ control, name: ['test'], }); }); expect(result.current).toEqual([undefined]); }); it('should return undefined', () => { const { result } = renderHook(() => { const { control } = useForm<{ test: string }>(); return useWatch({ control, name: 'test', }); }); expect(result.current).toBeUndefined(); }); it('should render with FormProvider', () => { const Provider = ({ children }: { children: React.ReactNode }) => { const methods = useForm<{ test: string }>(); return {children}; }; expect(() => renderHook(() => useWatch({ name: 'test' }), { wrapper: Provider, }), ).not.toThrow(); }); it('should remove input with shouldUnregister: true and deeply nested', async () => { type FormValue = { test: string; }; let submitData = {}; const Child = ({ control, register, }: { register: UseFormRegister; control: Control; }) => { const show = useWatch({ control, name: 'test', }); return <>{show && show !== 'test' && }; }; const Component = () => { const { register, control, handleSubmit } = useForm({ defaultValues: { test: 'bill', }, shouldUnregister: true, }); return (
{ submitData = data; })} > ); }; render(); fireEvent.change(screen.getByRole('textbox'), { target: { value: 'test' }, }); fireEvent.click(screen.getByRole('button', { name: 'submit' })); expect(submitData).toEqual({}); }); it('should return defaultValue with shouldUnregister set to true and keepDefaultValues', () => { const output: unknown[] = []; function App() { const { register, reset, control } = useForm({ defaultValues: { test: 'test' }, shouldUnregister: true, }); const inputs = useWatch({ control }); output.push(inputs); return (
); } render(); fireEvent.click(screen.getByRole('button')); fireEvent.change(screen.getByRole('textbox'), { target: { value: 'test' }, }); fireEvent.click(screen.getByRole('button')); expect(output).toEqual([ { test: 'test' }, { test: 'test' }, { test: 'test' }, { test: 'test' }, { test: 'test' }, { test: 'test' }, ]); }); it('should subscribe to exact input change', () => { const App = () => { const { control, register } = useForm(); const value = useWatch({ name: 'test', control, exact: true, defaultValue: 'test', }); return (

{value}

); }; render(); fireEvent.change(screen.getByRole('textbox'), { target: { value: '1234', }, }); expect(screen.getByText('test')).toBeVisible(); }); it('should return root object subscription', () => { function App() { const { register, control } = useForm({ defaultValues: { field: { firstName: 'value' } }, }); const field = useWatch({ control, name: 'field' }); return (

{field.firstName}

); } render(); fireEvent.change(screen.getByRole('textbox'), { target: { value: '123', }, }); fireEvent.change(screen.getByRole('textbox'), { target: { value: '234', }, }); fireEvent.change(screen.getByRole('textbox'), { target: { value: '345', }, }); expect(screen.getByText('345')).toBeVisible(); }); it('should avoid triggering extra callbacks', () => { const onChange = jest.fn(); type FormInputs = { firstName: string; }; const App = () => { const { register, formState: { errors }, clearErrors, watch, } = useForm(); React.useEffect(() => { const unsubscribe = watch(onChange)?.unsubscribe; return () => unsubscribe?.(); }, [watch]); return (
{errors.firstName &&

This Field is Required

}
); }; render(); fireEvent.click(screen.getByText('Clear All Errors')); expect(onChange).toHaveBeenCalledTimes(0); }); describe('when disabled prop is used', () => { it('should be able to disabled subscription and started with true', async () => { type FormValues = { test: string; }; const ChildComponent = ({ control, }: { control: Control; }) => { const [disabled, setDisabled] = React.useState(true); const test = useWatch({ control, name: 'test', disabled, }); return (

{test}

); }; const App = () => { const { register, control } = useForm({ defaultValues: { test: 'test', }, }); return (
); }; render(); fireEvent.change(screen.getByRole('textbox'), { target: { value: 'what', }, }); expect(screen.getByText('test')).toBeVisible(); fireEvent.click(screen.getByRole('button')); fireEvent.change(screen.getByRole('textbox'), { target: { value: 'what12345', }, }); expect(screen.getByText('what12345')).toBeVisible(); fireEvent.click(screen.getByRole('button')); fireEvent.change(screen.getByRole('textbox'), { target: { value: '12345', }, }); expect(screen.getByText('what12345')).toBeVisible(); }); it('should be able to toggle the subscription and started with false', async () => { type FormValues = { test: string; }; const ChildComponent = ({ control, }: { control: Control; }) => { const [disabled, setDisabled] = React.useState(false); const test = useWatch({ control, name: 'test', disabled, }); return (

{test}

); }; const WatchApp = () => { const { register, control } = useForm({ defaultValues: { test: 'test', }, }); return (
); }; render(); fireEvent.change(screen.getByRole('textbox'), { target: { value: 'what', }, }); expect(screen.getByText('what')).toBeVisible(); fireEvent.click(screen.getByRole('button')); fireEvent.change(screen.getByRole('textbox'), { target: { value: 'what12345', }, }); expect(screen.getByText('what')).toBeVisible(); }); }); describe('update', () => { it('should partial re-render', async () => { type FormInputs = { child: string; parent: string; }; let childCount = 0; const Child = ({ register, control, }: Pick, 'register' | 'control'>) => { useWatch({ name: 'child', control }); childCount++; return ; }; let parentCount = 0; const Parent = () => { const { register, handleSubmit, control, formState: { errors }, } = useForm(); parentCount++; return (
<>

{String(errors?.parent)}

); }; render(); const childInput = screen.getAllByRole('textbox')[1]; fireEvent.input(childInput, { target: { value: 'test' }, }); expect(parentCount).toBe(2); expect(childCount).toBe(3); parentCount = 0; childCount = 0; fireEvent.submit(screen.getByRole('button', { name: /submit/i })); await waitFor(() => expect(parentCount).toBe(1)); expect(childCount).toBe(2); parentCount = 0; childCount = 0; fireEvent.input(childInput, { target: { value: 'test1' } }); expect(parentCount).toBe(0); expect(childCount).toBe(1); }); it('should partial re-render with array name and exact option', async () => { type FormInputs = { child: string; childSecond: string; parent: string; }; let childCount = 0; let childSecondCount = 0; const Child = ({ register, control, }: Pick, 'register' | 'control'>) => { useWatch({ name: ['childSecond'], control }); childCount++; return ; }; const ChildSecond = ({ register, control, }: Pick, 'register' | 'control'>) => { useWatch({ name: ['childSecond'], control, exact: true }); childSecondCount++; return ; }; let parentCount = 0; const Parent = () => { const { register, handleSubmit, control, formState: { errors }, } = useForm(); parentCount++; return (
<>

{String(errors.parent)}

); }; render(); const childInput = screen.getAllByRole('textbox')[1]; const childSecondInput = screen.getAllByRole('textbox')[2]; fireEvent.input(childInput, { target: { value: 'test' }, }); expect(parentCount).toBe(2); expect(childCount).toBe(3); expect(childSecondCount).toBe(2); parentCount = 0; childCount = 0; childSecondCount = 0; fireEvent.submit(screen.getByRole('button', { name: /submit/i })); await waitFor(() => expect(parentCount).toBe(1)); expect(childCount).toBe(2); expect(childSecondCount).toBe(2); parentCount = 0; childCount = 0; childSecondCount = 0; fireEvent.input(childInput, { target: { value: 'test1' } }); expect(parentCount).toBe(0); expect(childCount).toBe(1); expect(childSecondCount).toBe(0); parentCount = 0; childCount = 0; childSecondCount = 0; fireEvent.input(childSecondInput, { target: { value: 'test2' } }); expect(parentCount).toBe(0); expect(childCount).toBe(1); expect(childSecondCount).toBe(1); }); it('should only subscribe change at useWatch level instead of useForm', () => { type FormValues = { test: string; test1: string; test2: string; }; let parentRenderCount = 0; let childRenderCount = 0; const Test = ({ control }: { control: Control }) => { useWatch({ control, }); childRenderCount++; return
test
; }; const Component = () => { const { control, register } = useForm(); parentRenderCount++; return (
); }; render(); fireEvent.change(screen.getAllByRole('textbox')[0], { target: { value: '1234', }, }); fireEvent.change(screen.getAllByRole('textbox')[1], { target: { value: '1234', }, }); fireEvent.change(screen.getAllByRole('textbox')[2], { target: { value: '1234', }, }); expect(parentRenderCount).toEqual(2); expect(childRenderCount).toEqual(5); }); it("should not re-render external component when field name don't match", async () => { type FormInputs = { test1: string; test2: string }; const Child = ({ control }: { control: Control }) => { useWatch({ name: 'test2', control }); return
; }; const Parent = () => { const { register, control } = useForm(); useWatch({ name: 'test1', control }); return (
); }; render(); fireEvent.input(screen.getAllByRole('textbox')[1], { target: { name: 'test2', value: 'value', }, }); }); it('should not throw error when null or undefined is set', () => { const watchedValue: Record = {}; const Component = () => { const { register, control } = useForm<{ test: string; test1: string; }>(); register('test'); register('test1'); watchedValue['test'] = useWatch({ name: 'test', control }); watchedValue['test1'] = useWatch({ name: 'test1', control }); return
; }; render(); expect(watchedValue).toEqual({ test: undefined, test1: undefined }); }); it('should return undefined when input gets unregistered', async () => { const Component = () => { const { register, control, unregister } = useForm<{ test: number }>(); const [show, setShow] = React.useState(true); const data: any = useWatch({ name: 'test', control }); return ( <> {show && } {data} ); }; render(); fireEvent.input(screen.getByRole('textbox'), { target: { value: 'test', }, }); expect(screen.getByText('test')).toBeVisible(); fireEvent.click(screen.getByRole('button')); expect(screen.queryByText('test')).not.toBeInTheDocument(); }); it('should return undefined when input get unregistered', () => { type FormValues = { test: string; }; const Test = ({ control }: { control: Control }) => { const value = useWatch({ control, name: 'test', }); return
{value === undefined ? 'yes' : 'no'}
; }; const Component = () => { const { register, control, unregister } = useForm({ defaultValues: { test: 'test', }, }); React.useEffect(() => { register('test'); }, [register]); return ( <> ); }; render(); fireEvent.click(screen.getByRole('button')); expect(screen.getByText('yes')).toBeVisible(); }); }); describe('fieldArray', () => { it('should watch correct input update with single field array input', () => { const inputValues: string[] = []; type FormValues = { labels: { displayName: string; internalName: string; }[]; }; function Item({ control, register, itemIndex, remove, }: { control: Control; register: UseFormReturn['register']; remove: UseFieldArrayReturn['remove']; itemIndex: number; }) { const actualValue = useWatch({ control, name: `labels.${itemIndex}.displayName` as const, }); inputValues.push(actualValue); return (
); } const Component = () => { const { control, register } = useForm({ defaultValues: { labels: [ { displayName: 'Type', internalName: 'type', }, { displayName: 'Number', internalName: 'number', }, { displayName: 'Totals', internalName: 'totals', }, ], }, }); const { fields, remove } = useFieldArray({ control, name: 'labels', }); return (
{fields.map((item, itemIndex) => ( ))} ); }; render(); fireEvent.click(screen.getAllByRole('button')[1]); expect(inputValues).toEqual([ 'Type', 'Number', 'Totals', 'Type', 'Number', 'Totals', 'Type', 'Number', 'Totals', 'Type', 'Totals', ]); }); it('should return shallow merged watch values', () => { const watchedValue: unknown[] = []; function App() { const methods = useForm({ defaultValues: { name: 'foo', arr: [], }, mode: 'onSubmit', reValidateMode: 'onChange', criteriaMode: 'all', shouldUnregister: false, }); return ( ); } function Preview() { const form = useWatch({}); watchedValue.push(form); return null; } function FieldArray() { useFieldArray({ name: 'arr', shouldUnregister: false, }); return null; } render(); expect(watchedValue).toEqual([ { arr: [], name: 'foo', }, { arr: [], name: 'foo', }, ]); }); }); describe('fieldArray with shouldUnregister true', () => { it('should watch correct input update with single field array input', async () => { const watchData: unknown[] = []; type Unpacked = T extends (infer U)[] ? U : T; type FormValues = { items: { prop: string }[]; }; function App() { const rhfProps = useForm({ defaultValues: { items: [{ prop: 'test' }, { prop: 'test1' }], }, shouldUnregister: true, }); const { control } = rhfProps; const { fields, insert, remove } = useFieldArray({ control, name: 'items', }); return (
{fields.map((item, index) => { return (
); })} ); } function Watcher({ itemsDefault, control, }: { itemsDefault: FormValues['items']; control: Control; }) { const useWatchedItems = useWatch({ name: 'items', control, defaultValue: itemsDefault, }); watchData.push(useWatchedItems); return (
{useWatchedItems.map((item, index) => { return (

Value {index}: {item.prop}

); })}
); } function Child({ index, itemDefault, control, }: { index: number; itemDefault: Unpacked; control: Control; }) { const { field } = useController({ name: `items.${index}.prop` as const, control, defaultValue: itemDefault.prop, }); return ; } render(); expect(screen.getByText('Value 0: test')).toBeVisible(); expect(screen.getByText('Value 1: test1')).toBeVisible(); expect( screen.queryByText('Value 1: ShouldBeTHere'), ).not.toBeInTheDocument(); fireEvent.click(screen.getAllByRole('button', { name: 'insert' })[0]); expect(await screen.findByText('Value 1: ShouldBeTHere')).toBeVisible(); expect(screen.getByText('Value 2: test1')).toBeVisible(); fireEvent.click(screen.getAllByRole('button', { name: 'remove' })[0]); expect( screen.queryByText('Value 2: ShouldBeTHere'), ).not.toBeInTheDocument(); expect(watchData).toMatchSnapshot(); }); }); describe('reset', () => { it('should return updated default value with watched field after reset', async () => { type FormValues = { test: string; name: string; }; function Watcher({ control }: { control: Control }) { const testField = useWatch({ name: 'test', control: control, }); return
{testField}
; } function Component() { const { reset, control } = useForm({ defaultValues: { test: '', name: '', }, }); React.useEffect(() => { reset({ test: 'test', }); }, [reset]); return ; } render(); expect(await screen.findByText('test')).toBeVisible(); }); it('should return default value of reset method', async () => { const Component = () => { const { register, reset, control } = useForm<{ test: string; }>(); const test = useWatch<{ test: string; }>({ name: 'test', control }); React.useEffect(() => { reset({ test: 'default' }); }, [reset]); return (
{test}
); }; render(); expect(await screen.findByText('default')).toBeDefined(); }); it('should re-register watched input after reset', async () => { type FormValues = { firstName: string; }; function LivePreview({ control }: { control: Control }) { const value = useWatch({ name: `firstName`, defaultValue: 'yes', control, }); return

{value}

; } const Component = () => { const formMethods = useForm(); const { control, reset, register } = formMethods; React.useEffect(() => { reset({ firstName: 'firstName', }); }, [reset]); return ( <> ); }; render(); expect(screen.getByText('firstName')).toBeVisible(); fireEvent.change(screen.getByRole('textbox'), { target: { value: '123' }, }); expect(screen.getByText('123')).toBeVisible(); }); it('should fallback to inline defaultValue with reset API', () => { const App = () => { const { control, reset } = useForm(); const value = useWatch({ name: 'test', defaultValue: 'yes', control, }); React.useEffect(() => { reset({}); }, [reset]); return

{value ? 'yes' : 'no'}

; }; render(); expect(screen.getByText('yes')).toBeVisible(); }); describe('with useFieldArray', () => { // issue: https://github.com/react-hook-form/react-hook-form/issues/2229 it('should return current value with radio type', () => { type FormValues = { options: { option: string }[]; }; const watchedValue: object[] = []; const Test = ({ control }: { control: Control }) => { const values = useWatch({ control }); const options = values.options; watchedValue.push(values); return (

First: {options?.[0].option}

Second: {options?.[1].option}

); }; const Component = () => { const { register, reset, control } = useForm(); const { fields } = useFieldArray({ name: 'options', control }); React.useEffect(() => { reset({ options: [ { option: 'yes', }, { option: 'yes', }, ], }); }, [reset]); return (
{fields.map((_, i) => (
))} ); }; render(); const firstField = screen.getByTestId('field-0'); expect(within(firstField).getByLabelText('Yes')).toBeChecked(); expect(screen.getByText('First: yes')).toBeVisible(); const secondField = screen.getByTestId('field-1'); expect(within(secondField).getByLabelText('Yes')).toBeChecked(); expect(screen.getByText('Second: yes')).toBeVisible(); fireEvent.click(within(firstField).getByLabelText('No')); expect(screen.getByText('First: no')).toBeVisible(); expect(screen.getByText('Second: yes')).toBeVisible(); // Let's check all values of renders with implicitly the number of render (for each value) expect(watchedValue).toMatchSnapshot(); }); it("should watch item correctly with useFieldArray's remove method", async () => { let watchedValue: { [x: string]: any } | undefined; const Component = () => { const { register, control } = useForm<{ test: { firstName: string; lsatName: string; }[]; }>({ defaultValues: { test: [{ firstName: 'test' }, { firstName: 'test1' }], }, }); const { fields, remove } = useFieldArray({ name: 'test', control, }); watchedValue = useWatch({ name: 'test', control, }); return (
{fields.map((item, i) => (
))}
); }; render(); expect(watchedValue).toEqual([ { firstName: 'test' }, { firstName: 'test1' }, ]); fireEvent.click(screen.getAllByRole('button')[0]); expect(watchedValue).toEqual([{ firstName: 'test1' }]); }); }); describe('with custom register', () => { it('should return default value of reset method when value is not empty', async () => { const Component = () => { const { register, reset, control } = useForm<{ test: string; }>(); const test = useWatch<{ test: string; }>({ name: 'test', control, }); React.useEffect(() => { register('test'); }, [register]); React.useEffect(() => { reset({ test: 'default1' }); }, [reset]); return (
{test}
); }; render(); expect((await screen.findByTestId('result')).textContent).toBe( 'default1', ); }); it('should return default value of reset method', async () => { const Component = () => { const { register, reset, control } = useForm<{ test: string; }>(); const test = useWatch<{ test: string; }>({ name: 'test', control }); React.useEffect(() => { register('test'); }, [register]); React.useEffect(() => { reset({ test: 'default' }); }, [reset]); return (
{test}
); }; render(); expect(await screen.findByText('default')).toBeDefined(); }); it('should return default value', async () => { const Component = () => { const { register, reset, control } = useForm<{ test: string }>({ defaultValues: { test: 'test', }, }); const test = useWatch<{ test: string }>({ name: 'test', control, }); React.useEffect(() => { register('test'); }, [register]); React.useEffect(() => { reset(); }, [reset]); return (
{test}
); }; render(); expect(await screen.findByText('test')).toBeDefined(); }); }); it('Should update the value immediately after reset when used with Controller', async () => { const getDefaultValue = () => ({ test: undefined, }); const Component = () => { const { reset, control } = useForm({ defaultValues: getDefaultValue(), }); return (
( )} /> ); }; render(); fireEvent.change(screen.getByTestId('test-select'), { target: { value: 'test1' }, }); expect(screen.getByTestId('test-select')).toHaveValue('test1'); fireEvent.click(screen.getByTestId('reset-button')); expect(screen.getByTestId('test-select')).toHaveValue(''); fireEvent.change(screen.getByTestId('test-select'), { target: { value: 'test2' }, }); expect(screen.getByTestId('test-select')).toHaveValue('test2'); fireEvent.click(screen.getByTestId('reset-button')); expect(screen.getByTestId('test-select')).toHaveValue(''); }); }); describe('unregister', () => { it('should return correct value after input get unregistered', async () => { type FormValues = { test: string }; const Component = ({ control }: { control: Control }) => { const test = useWatch<{ test: string }>({ name: 'test', control }); return
{test === undefined ? 'no' : test}
; }; const Form = () => { const { control, unregister, register } = useForm({ defaultValues: { test: 'test' }, }); return ( <> ); }; render(
); expect(screen.getByText('test')).toBeVisible(); fireEvent.click(screen.getByRole('button')); expect(screen.getByText('no')).toBeVisible(); }); }); describe('setValue', () => { it('should return correct value after input get unregistered', async () => { type FormValues = { test: string }; const Child = ({ register }: UseFormReturn) => { return ; }; const Component = ({ control }: { control: Control }) => { const test = useWatch<{ test: string }>({ name: 'test', control }); return
{test === 'bill' ? 'no' : test}
; }; const Form = () => { const methods = useForm({ defaultValues: { test: 'test' }, }); const { setValue } = methods; React.useEffect(() => { setValue('test', 'bill'); }, [setValue]); return ( <> ); }; render(); expect(await screen.findByText('no')).toBeVisible(); }); it('should keep set type after set value', async () => { const Form = () => { const { control, setValue } = useForm({ defaultValues: { test: new Set(['test']) }, }); const { field } = useController({ control, name: 'test', }); React.useEffect(() => { setValue('test', new Set(['test'])); }, [setValue]); return <>{field.value instanceof Set ? 'yes' : 'no'}; }; render(); await waitFor(() => { screen.getByText('yes'); }); }); it('should watch nested object field update', () => { interface FormData { one: { two: { dep: number; }; }; } const Component1 = () => { const watchedDep = useWatch({ name: 'one.two.dep' }); return

{watchedDep}

; }; const Component2 = () => { const { register, setValue } = useFormContext(); const field = register('one.two.dep'); return ( <> ); }; const Component: React.FC = () => { const form = useForm({ defaultValues: { one: { two: { dep: 111, }, }, }, }); return ( <> ); }; render(); fireEvent.click(screen.getByRole('button')); expect(screen.getByText('333')).toBeVisible(); expect((screen.getByRole('textbox') as HTMLInputElement).value).toEqual( '333', ); }); it('should return field value, not resolver transformed value', async () => { const Form = () => { const { control, setValue } = useForm< { test: string }, any, { test: number } >({ defaultValues: { test: '3' }, resolver: ({ test }) => ({ values: { test: parseInt(test, 10) }, errors: {}, }), }); const { field } = useController({ control, name: 'test', }); React.useEffect(() => { setValue('test', '9'); }, [setValue]); return <>{field.value === '9' ? 'yes' : 'no'}; }; render(); await waitFor(() => { screen.getByText('yes'); }); }); it('should return field value when resolver transformed value is a different shape', async () => { const Form = () => { const { control, setValue } = useForm< { alpha: string; beta: string }, any, { add: number } >({ defaultValues: { alpha: '3', beta: '4' }, resolver: ({ alpha, beta }) => ({ values: { add: parseInt(alpha, 10) + parseInt(beta, 10) }, errors: {}, }), }); const { field } = useController({ control, name: 'alpha', }); React.useEffect(() => { setValue('alpha', '9'); }, [setValue]); return <>{field.value === '9' ? 'yes' : 'no'}; }; render(); await waitFor(() => { screen.getByText('yes'); }); }); }); describe('formContext', () => { it('should work with form context', async () => { const Component = () => { const test = useWatch<{ test: string }>({ name: 'test' }); return
{test}
; }; const Form = () => { const methods = useForm<{ test: string }>({ defaultValues: { test: 'test' }, }); return ( ); }; render(); expect(await screen.findByText('test')).toBeDefined(); }); }); describe('compute ', () => { it('should only update when value changed within compute', () => { type FormValue = { test: string; }; let renderCount = 0; const Form = () => { const methods = useForm({ defaultValues: { test: '' }, }); const watchedValue = useWatch({ control: methods.control, compute: (data: FormValue) => data.test?.length > 2, }); renderCount++; return (

{watchedValue ? 'yes' : 'no'}

{renderCount}

); }; render(); screen.getByText('no'); fireEvent.change(screen.getByRole('textbox'), { target: { value: '12' }, }); screen.getByText('no'); fireEvent.change(screen.getByRole('textbox'), { target: { value: '123' }, }); screen.getByText('yes'); expect(renderCount).toEqual(4); fireEvent.change(screen.getByRole('textbox'), { target: { value: '12' }, }); screen.getByText('no'); expect(renderCount).toEqual(5); fireEvent.change(screen.getByRole('textbox'), { target: { value: '1' }, }); screen.getByText('no'); expect(renderCount).toEqual(5); }); }); });