Test React Hooks with react-native-testing-library

HookTest.spec.ts

import * as React from 'react'
import { fireEvent, render } from 'react-native-testing-library'

import { HookTest } from '../HookTest'

describe('Test Hooks', () => {

  test('changeText', () => {
    const { getByTestId, getByPlaceholder, queryByDisplayValue } = render(
      <HookTest />)

    const output = getByTestId('subText')
    const input = getByPlaceholder(/Input Text/i)
    expect(input).not.toBeNull()
    expect(queryByDisplayValue('Default text')).not.toBeNull()

    const testText = 'Changed text'
    fireEvent(input, 'onChangeText', testText)

    expect(queryByDisplayValue('Default text')).toBeNull()
    expect(output.props.children).toBe(testText)

  })

  test('onSubmitEditing', () => {
    const { getByTestId, getByPlaceholder } = render(
      <HookTest />)

    const output = getByTestId('subText')
    const input = getByPlaceholder(/Input Text/i)

    const testText = 'Submitted text'
    fireEvent(input, 'onSubmitEditing', { nativeEvent: { text: testText } })

    expect(output.props.children).toBe(testText)

  })

  test('mocked callback', () => {
    const myMock = jest.fn()
    const { getByTestId } = render(
      <HookTest myMock={myMock} />)

    const onPressComponent = getByTestId('onPressComponent')

    fireEvent(onPressComponent, 'onPress')

    expect(myMock).toHaveBeenCalled()
  })

})

onSubmitEditing is not passing
the value is not matching with the expected

expect(received).toBe(expected)
expected = "Submitted text"
received = undefined

@goodpic