javascript - Enzyme 在浅层渲染的 React 组件上为 prop 返回 null

Question

问题

我刚刚开始进行 enzyme 和 react 测试。我正在尝试让 enzyme 与 karma 和 webpack 在一个简单的 react 组件上一起工作。我的问题是包装器上的 prop() 返回 null，我不确定为什么。

Greeter.js

import React from 'react';

/*
 * A trivial component we added while trying to get the react testing  working
 * */

export default class Greeter extends React.Component {
constructor(props) {
    super(props);
    this.state = { name: props.initialName };

    this.greeterText = this.greeterText.bind(this);
}

greeterText() {
    return (<p>Hello, {this.state.name}!</p>);
}

render() {
    return (<div className="greeter">
        {this.greeterText()}
    </div>);
  }
}

Greeter.defaultProps = { initialName: "World" };

Greeter.propTypes = {
  initialName: React.PropTypes.string
};

greeter.spec.js

import Greeter from '../../components/test/Greeter';
import React from 'react';
import { shallow } from 'enzyme';


describe("Simple testing with shallow rendering", () => {
  beforeEach(function() {
    let initialName = "joe";
    this.wrapper = shallow(<Greeter initialName={initialName} />);
  });

  it("renders default Greeter", function() {
    console.log(this.wrapper.find(".greeter").text());
    console.log(this.wrapper.debug());
    console.log(this.wrapper.state('name'));
    expect(this.wrapper.state('name')).to.equal("joe");
    expect(this.wrapper.prop('initialName')).to.equal("joe");
   });
 });

结果

Simple testing with shallow rendering × renders default Greeter Chrome 50.0.2661 (Windows 10 0.0.0) AssertionError: expected undefined to equal 'joe' at Assertion.assertEqual >>(F:/web/forms/node_modules/chai/chai.js:776:12) at Assertion.ctx.(anonymous function) [as equal] (F:web/forms/node_modules/chai/chai.js:4192:25) at Context. (F:web/forms/spec/components/greeter.spec.js:9:2932 <- webpack:///spec/components/greeter.spec.js:18:52)

堆栈

• react 0.14.8
• 业力
• 网页包
• enzyme 2.2.0

Answer 1

如果你想像这样测试传入的 Prop ，请像这样使用mount:

  it('allows us to set props', () => {
    const wrapper = mount(<Foo bar="baz" />);
    expect(wrapper.props().bar).to.equal("baz");
    wrapper.setProps({ bar: "foo" });
    expect(wrapper.props().bar).to.equal("foo");
  });