酶键模拟不触发onPress功能

Question

目前正在尝试测试按钮'onPress'在单击后是否已被调用，但是我遇到了一些麻烦。在我的fires onPress function when button is clicked测试用例中，它可以找到按钮以及除模拟点击之外的所有内容：

SignUp.test.js

这是我的帮助代码：

SignUp.js

Sign Up Page › fires onPress function when button is clicked

    expect(jest.fn()).toHaveBeenCalled()

    Expected number of calls: >= 1
    Received number of calls:    0

      28 |     // wrapper.find('#navigate').prop('onPress')();
      29 |     wrapper.find('#navigate').at(0).simulate('click');
    > 30 |     expect(onPress).toHaveBeenCalled();
         |                     ^
      31 |   });
      32 | });
      33 |

SignUp.test.js

const SignUp = ({ navigation }) => {
  const navigateOnPress = () => navigation.navigate('SignIn');

  return (
    <View style={Styles.container}>
      <Text>SignUp</Text>
      <Button
        id="navigate"
        title="Press me"
        onPress={navigateOnPress}
      />
    </View>
  );
};

Answer 1

通过直接调用onPress属性并查看是否调用了传递给该属性的函数来解决。

import React from 'react';
import { shallow } from 'enzyme';

import SignUp from '../../../components/SignUp/SignUp';

describe('Sign Up Page', () => {
  function render(args) {
    const defaultProps = {
      navigation: {
        navigate: jest.fn(),
      },
    };

    const props = {
      ...defaultProps, ...args,
    };

    return shallow(<SignUp {...props} />);
  }
  it('renders the sign up page', () => {
    const wrapper = render();
    expect(wrapper).toMatchSnapshot();
  });

  it('fires onPress function when button is clicked', () => {
    const wrapper = render();
    const onPress = jest.fn();
    wrapper.find('#navigate').prop('onPress')();
    wrapper.find('#navigate').at(0).simulate('click');
    expect(onPress).toHaveBeenCalled();
  });
});