Enzyme 在测试 React 组件时会忽略某些 prop 值

Question

谁能帮我解释一下jest中的以下测试？

StateIdText.jsx

import React, { Component, PropTypes } from 'react';

class StateIdTxt extends Component {
    propTypes: {
        x: PropTypes.number.isRequired,
        y: PropTypes.number.isRequired,
        stateId: PropTypes.number.isRequired
    }

    render() {
        const {x, y, stateId} = this.props;
        return (
                <text x={x} y={y}
                      textAnchor="end"
                      dominantBaseline="text-before-edge"
                      fontSize=".7em" fill="blue">
                    {stateId}
                </text>
        );
    }
}

export default StateIdTxt;

StateIdTxt.test.js

import React from 'react';
import {mount, render, shallow} from 'enzyme';

import StateIdTxt from './StateCoordTxt.jsx';

it('shallow <StateIdTxt />', () => {
    const wrapper = shallow(<StateIdTxt x={1.5} y={2.1} stateId={99} />);
    expect(wrapper.prop('x')).toEqual(1.5);
    expect(wrapper.prop('y')).toEqual(2.1);
    expect(wrapper.prop('stateId')).toBeUndefined();

    expect(wrapper.prop('textAnchor')).toBe('start'); // how come not end?
    expect(wrapper.prop('dominantBaseline')).toBe('text-before-edge');
    expect(wrapper.prop('fontSize')).toBe('.7em');
    expect(wrapper.prop('fill')).toBe('blue');
});

为什么wrapper.prop('textAnchor') 期望它通过的“开始”而不是“结束”？我实际上可以将“结束”更改为其他随机文本，并且测试仍然通过。

Answer 1

根据您在帖子中提到的文件名，我认为您在StateIdTxt.test.js 的导入中有错字：

import StateIdTxt from './StateCoordTxt.jsx';

应该是这样的

import StateIdTxt from './StateIdTxt.jsx';