问为什么用jest.mock模拟expo时，@expo/向量图标没有定义？

EN

jest.mock('expo', () => {
  const { View } = require('react-native');
  const constantsMock = { // the camera class has constants defined on it
    Type: {
      back: 'BACK',
      front: 'FRONT',
    },
  };
  const cameraMock = Object.assign({}, View, { Constants: constantsMock }); // assign so we can modify a copy, not the orig View - since its passed by reference

  return {
    Permissions: {
      askAsync: jest.fn(),
    },
    Camera: cameraMock,
    CameraObject: View,
  };
});

Warning: React.createElement: type is invalid -- expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.

    Check the render method of `InKeyboardCamera`.
        in InKeyboardCamera

(<SimpleLineIcons name="refresh" size={19} color="white" />)

import { SimpleLineIcons } from '@expo/vector-icons';

jest.mock('@expo/vector-icons', () => {
  const { View } = require('react-native');
  return {
    SimpleLineIcons: View,
    Ionicons: View,
  };
});