u-fit/frontend/lib/__tests__/forms.test.tsx

import { renderHook, act } from '@testing-library/react-hooks'

import useFormHandler from '../forms'

describe('form hook return values', () => {

  const { result } = renderHook(() => useFormHandler({ var: 'val' }, values => { return {} }))

  it('returns correct initial states.', () => {
    expect(result.current.values.var).toBe('val')
    expect(result.current.errors).toEqual({})
    expect(result.current.isSubmitting).toBe(false)
  })

  it('returns input element properties for valid input names.', () => {
    expect(result.current.inputProps('var')).toMatchObject({
      name: 'var', id: 'var', onBlur: expect.anything(), onChange: expect.anything()
    })
  })

  it('throws error for invalid input names.', () => {
    expect(() => result.current.inputProps('doh!')).toThrow()
  })

  it('returns form submission properties.', () => {
    expect(result.current.submitProps()).toMatchObject({
      onSubmit: expect.anything()
    })
  })

  it('sets the isSubmitting flag.', () => {
    act(() => result.current.handleSubmit({ preventDefault: () => { } }))

    expect(result.current.isSubmitting).toBe(true)
  })



})