shallow rendering可以把组件当做一个单元来测试，而且确保不会因为子组件的行为而直接出现断言（Shallow rendering is useful to constrain yourself to testing a component as a unit, and to ensure that your tests aren’t indirectly asserting on behavior of child components.）

import { shallow } from 'enzyme';

describe('<MyComponent />', () => {

  it('should render three <Foo /> components', () => {
    const wrapper = shallow(<MyComponent />);
    expect(wrapper.find(Foo)).to.have.length(3);
  });

  it('should render an `.icon-star`', () => {
    const wrapper = shallow(<MyComponent />);
    expect(wrapper.find('.icon-star')).to.have.length(1);
  });

  it('should render children when passed in', () => {
    const wrapper = shallow(
      <MyComponent>
        <div className="unique" />
      </MyComponent>
    );
    expect(wrapper.contains(<div className="unique" />)).to.equal(true);
  });

  it('simulates click events', () => {
    const onButtonClick = sinon.spy();
    const wrapper = shallow(
      <Foo onButtonClick={onButtonClick} />
    );
    wrapper.find('button').simulate('click');
    expect(onButtonClick.calledOnce).to.equal(true);
  });

});

shallow(node[, options]) => ShallowWrapper

参数

1. node (ReactElement)要渲染的节点

2. options (对象 [可选]):

3. options.context: (对象 [可选]): 传给组件的Context

返回

ShallowWrapper：这是一个cheerio的解析对象

API

• .find(selector) => ShallowWrapper
  找到所有匹配的节点

• .findWhere(predicate) => ShallowWrapper
  找到所有渲染树下满足函数内判断的节点

• .filter(selector) => ShallowWrapper
  过滤匹配的节点

• .filterWhere(predicate) => ShallowWrapper

• .contains(nodeOrNodes) => Boolean

• .containsMatchingElement(node) => Boolean

• .containsAllMatchingElements(nodes) => Boolean

• .containsAllMatchingElements(nodes) => Boolean

• .equals(node) => Boolean

• .matchesElement(node) => Boolean

• .hasClass(className) => Boolean

• .is(selector) => Boolean

• .isEmpty() => Boolean

• .not(selector) => ShallowWrapper

• .children() => ShallowWrapper

• .childAt(index) => ShallowWrapper

• .parents() => ShallowWrapper

• .parent() => ShallowWrapper

• .closest(selector) => ShallowWrapper

• .shallow([options]) => ShallowWrapper

• .render() => CheerioWrapper

参照这里，不一一列举，方法和jQuery