reactjs组件的unittest在作为道具传递的函数上失败

我正在尝试为一个简单的组件编写一个单元测试。

这是我的组件:

const ErrorWrpper = (props) =>(
<div className={props.class} style={props.validateForm(props.inputType)?
{display: 'none'}:{}}>
<span>{props.message}</span></div>
)
 export default  ErrorWrpper;

这是我的测试:

import React from 'react';
import { expect } from '../../test_helper';
import { shallow } from 'enzyme';
import { it, describe, beforeEach } from 'mocha';
import  ErrorWrapper  from '../../../src/app/components/login/ErrorWrapper';

let errorWrapper;
describe("ErrorWrapper component unit tests", () => {
 function validateForm(test){

}
before(() => {

    errorWrapper = shallow(<ErrorWrapper class="test"  inputType="all" validateForm={this.validateForm}/>);
});


// these tests check that each className that should exist, exists
describe("className check", () => {
    it('should have className test', () => {
        expect(errorWrapper.find('test')).to.exist;
    });
})
})

现在,当我运行它时,我得到以下信息:

ErrorWrapper component unit tests "before all" hook:
 TypeError: Cannot read property 'validateForm' of undefined

正如您所看到的,我试图将validateError函数作为道具提供给您,但仍然出现了错误。有什么想法吗?