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    当前位置：站长学院 > 综合教程 > Jest+Enzyme进行React测试--环境搭建+Enzyme基础知识介绍

    Jest+Enzyme进行React测试--环境搭建+Enzyme基础知识介绍

    正文概述 掘金(sokach)   2021-07-09   767

    如何编写前端测试一直是想了解的领域，之对jest测试的认知一直停留在expect和toBe的高度。这次将学习Jest+Enzyme如何对React项目进行测试。

    环境搭建

    准备react项目

    通过create-react-app搭建一个基本react项目供测试使用。我使用的项目是学习技术胖的React学习路线搭建的项目。

    搭建测试环境

    安装依赖：

     npm install jest --save-dev
 npm install enzyme --save-dev
 npm install enzyme-to-json --save-dev
 npm install enzyme-adapter-react-16

    配置packang.json:

      "scripts": {
    "test": "jest"
  }

    Jest配置文件

    生成jest配置文件

    npx jest --init

    在新生成的jest配置文件jest.config.js中进行配置：

      rootDir: './',
  setupFiles: [
    "<rootDir>/test/setup.js"
  ],
  moduleFileExtensions: [
    "js",
    "jsx",
    "ts",
    "tsx",
    "json",
    "node"
  ],

    setup.js文件

    import Enzyme from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';

Enzyme.configure({ adapter: new Adapter() });

    在测试中可定会使用使用es6的import和export，所以需要通过babel来进行将es6模块转换成commonJs模块。

    npm install @babel/core @babel/preset-env

    .babelrc文件

    {
  "presets": ["@babel/preset-env", "@babel/preset-react"]
}

    编写测试

    待测试的组件：

    // App.js
import React, { Component } from 'react';

class App extends Component {
  render() {
    return (
      <div>
        <h1>hello World</h1>
      </div>
    )
  }
}

export default App;

    测试代码：

    //app.test.js
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find('h1').text()).toBe('hello World')
  })
})

    执行npm test产看运行结果如下：

    Jest+Enzyme进行React测试--环境搭建+Enzyme基础知识介绍

    Enzymejs

    我所理解Enzyme的作用就是将要测试的组件进行渲染，使用户可以在测试环境中对UI渲染情况、DOM事件等进行测试。

    参考文献

    官方文档

    常用API

    .at(index)

    可以理解为根据索引返回节点。嵌套的也在内。

    举个?

    // 待测试组件
import React, { Component } from 'react';

class App extends Component {
  render() {
    return (
      <div>
        <h1>hello</h1>
        <h1>World</h1>
      </div>
    )
  }
}

export default App;

// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    console.log(app.find('h1').at(0))
    console.log(app.find('h1').at(1))
    expect(app.find('h1').at(0).text()).toBe('hello')
    expect(app.find('h1').at(1).text()).toBe('World')
  })
})

    返回值：

    Jest+Enzyme进行React测试--环境搭建+Enzyme基础知识介绍

    再举个?

    // 待测试组件
import React, { Component } from 'react';

class App extends Component {
  render() {
    return (
      <div>
        <h1>hello</h1>
        <h1>World</h1>
        // ********change start******
        <div>
          <h1>!!</h1>
        </div>
        // ********change end******
      </div>
    )
  }
}

export default App;

// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find('h1').at(0).text()).toBe('hello')
    expect(app.find('h1').at(1).text()).toBe('World')
    // **********change start*********
    expect(app.find('h1').at(2).text()).toBe('.')
     // **********change end*********
  })
})

    测试结果：

    Jest+Enzyme进行React测试--环境搭建+Enzyme基础知识介绍

    .childAt(index)

    返回具有指定索引的子元素到新的wrapper。

    举个?

    // 待测试的组件
import React, { Component } from 'react';

class App extends Component {
  render() {
    return (
      <div>
        <h1>hello</h1>
        <h1>World</h1>
      </div>
    )
  }
}
export default App;

// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    // 注意是查找的div 不是h1
    expect(app.find('div').childAt(0).text()).toBe('hello')
    expect(app.find('div').childAt(1).text()).toBe('World')
  })
})

    测试结果

    Jest+Enzyme进行React测试--环境搭建+Enzyme基础知识介绍

    再举个?

    测试代码不变，将待测试组件变成如下结构：

    import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div>
        <h1>hello</h1>
        <h1>World</h1>
        // change start------------
        <div>
          <h1>!!</h1>
        </div>
        // change end--------------
      </div>
    )
  }
}
export default App;

    测试结果

    Jest+Enzyme进行React测试--环境搭建+Enzyme基础知识介绍

    总结：要根据独一无二的条件(比如只有一个div)进行find的结果才可使用childAt。

    .find(selector)

    根据选择器，找到渲染树中的节点。

    selector 参数：

    • 标签：find('tag')
    • 类名：find('.className')
    • id：.find('#id')
    • 组合：.find('tag.className')
    • 构造函数：.find(Foo)
    • 组件显示名字：.find('Foo')
    • 对象属性选择器：.find({ prop: 'value' })

    举一堆???????

    // MyCom组件
import React, { Component } from 'react';
class MyCom extends Component {
  render() {
    return (
      <h1>xixi</h1>
    )
  }
}
export default MyCom;

// 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div>
        <h1 className='helloClass'>hello</h1>
        <h1 id="worldID">World</h1>
        <span className="spanClass">ya</span>
        <span>haha</span>
        <span fo="heheKey">hehe</span>
        <MyCom />
      </div>
    )
  }
}
export default App;

// 测试代码
import React from 'react';
import App from '../src/App';
import MyCom from '../src/MyCom';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find('span').at(1).text()).toBe('haha')
    expect(app.find('.helloClass').text()).toBe('hello')
    expect(app.find('#worldID').text()).toBe('World')
    expect(app.find('span.spanClass').text()).toBe('ya')
    expect(app.find('MyCom').text()).toBe('<MyCom />') // 不能匹配到xixi,子组件不渲染
    expect(app.find(MyCom).text()).toBe('<MyCom />')
    expect(app.find({ fo: 'heheKey' }).text()).toBe('hehe')
  })
})

    findWhere(predicate)

    找到渲染树中里被的断言函数（predicate）返回true的节点。断言函数返回不布尔值。

    举个?

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div>
        <h1 className='helloClass'>hello</h1>
        <h1 className='helloClass1'>helloyaya</h1>
        <h1 id="worldID">World</h1>
        <span className="spanClass">ya</span>
        <span>haha</span>
        <span fo="heheKey">hehe</span>
        <MyCom />
      </div>
    )
  }
}
export default App;

// 测试代码
import React from 'react';
import App from '../src/App';
import MyCom from '../src/MyCom';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    const wrapper = app.findWhere(n => n.text().indexOf('hello') > -1);
    expect(wrapper.find('.helloClass').text()).toBe('hello')
    expect(wrapper.find('.helloClass1').text()).toBe('helloyaya')
  })
})
// 测试通过！！！

    我所理解的这个api类似于数组中的filter，满足条件的节点被过滤出来，组成到新的Wrapper中被返回。在返回的Wrapper中我们可以再进行find操作。

    .filter(selector)

    将与提供的选择器匹配的节点包装成wrapper返回。

    举个?

    // 待测试的组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div>
        <h1 className='helloClass'>hello</h1>
        <h1 id="worldID">World</h1>
        <span className="spanClass">ya</span>
        <span>haha</span>
        <span fo="heheKey">hehe</span>
        <MyCom />
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find('h1').filter('.helloClass').text()).toBe('hello');
    expect(app.find('h1').filter('#worldID').text()).toBe('World');
  })
})
// 测试通过

    总结：从已经查找的节点中过滤出满足条件的节点

    .filterWhere(predicate)

    返回满足断言函数的节点。

    举个?

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <>
        <h1 className='helloClass'>hello</h1>
        <h1 id="worldID">World</h1>
        <span className="spanClass">ya</span>
        <span>haha</span>
        <span fo="heheKey">hehe</span>
        <MyCom />
      </>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find('h1').filterWhere(n => n.text() === 'hello').text()).toBe('hello');

    const wrapper = app.find('span').filterWhere(n => n.text().indexOf('h') > -1);
    expect(wrapper.at(0).text()).toBe('haha');
    expect(wrapper.at(1).text()).toBe('hehe');
  })
})
// 测试通过

    .contains(nodeOrNodes)

    返回布尔值，表示给定的节点（nodeOrNodes）是否存在于渲染树中。可以检测props以及相应的值。也就是说，如果预期元素与包装器的元素有相同的props并且共享相同的值就返回true。

    举个?

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div>
        <h1 className='helloClass'>hello</h1>
        <h1 id="worldID">World</h1>
        <span className="spanClass">ya</span>
        <span>haha</span>
        <span fo="heheKey">hehe</span>
        <MyCom />
      </div>
    )
  }
}
export default App;

// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.contains(<h1>hello</h1>)).toEqual(false);
    expect(app.contains(<h1 className={'a'}>hello</h1>)).toEqual(false);
    expect(app.contains(<h1 className={'helloClass'}>Hello</h1>)).toEqual(false);
    expect(app.contains(<h1 className={'helloClass'}>hello</h1>)).toEqual(true);
    expect(app.contains(<h1 className='helloClass'>hello</h1>)).toEqual(true);

    expect(app.contains([
      <h1 id="worldID">World</h1>,
      <span className="spanClass">ya</span>
    ])).toEqual(true)

    expect(app.contains([
      <h1 id="worldID">World</h1>,
      <span>haha</span>
    ])).toEqual(false)
  })
})

    总结：严格匹配，不能差一丝一毫，多个节点必须相邻，否则不成功。

    .containsMatchingElement(node)

    返回浅渲染树中是否存在给定node节点的布尔值。

    举个?

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div>
        <h1 className='helloClass' data-fo="foo">hello</h1>
        <h1 id="worldID">World</h1>
        <span className="spanClass">ya</span>
        <span>haha</span>
        <span fo="heheKey">hehe</span>
        <MyCom />
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.containsMatchingElement(<h1>hello</h1>)).toEqual(true);
    expect(app.containsMatchingElement(<h1 className='helloClass' >hello</h1>)).toEqual(true);
    expect(app.containsMatchingElement(<h1 data-fo='foo'>hello</h1>)).toEqual(true);
    expect(app.containsMatchingElement(<h1 data-fo='foo-data'>hello</h1>)).toEqual(false);
    expect(app.containsMatchingElement(<h1 data-fo='foo' />)).toEqual(false);
  })
})

    总结下来就是：可少不可多。props和值完全对用即可，不像contains那样严格。

    .containsAllMatchingElements(nodes)

    给定所有元素是否都存在于浅渲染树中。遵循containsMatchingElement匹配原则。

    举个?

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div>
        <h1 className='helloClass'>hello</h1>
        <h1 id="worldID">World</h1>
        <span className="spanClass">ya</span>
        <span>haha</span>
        <span fo="heheKey">hehe</span>
        <MyCom />
      </div>
    )
  }
}
export default App;

// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.containsAllMatchingElements([
      <h1>hello</h1>,
      <h1 id="worldID">World</h1>
    ])).toEqual(true);

    expect(app.containsAllMatchingElements([
      <h1 className='helloClass'>hello</h1>,
      <h1 id="worldID">World</h1>
    ])).toEqual(true);

    expect(app.containsAllMatchingElements([
      <h1 className='helloClass'>hello</h1>,
      <span>haha</span>
    ])).toEqual(true);
  })
})
// 测试通过

    .containsAnyMatchingElements(nodes)

    给定节点（nodes）中有一个匹配就返回true。

    举个?

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div>
        <h1 className='helloClass'>hello</h1>
        <h1 id="worldID">World</h1>
        <span className="spanClass">ya</span>
        <span>haha</span>
        <span fo="heheKey">hehe</span>
        <MyCom />
      </div>
    )
  }
}
export default App;
// 测代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.containsAnyMatchingElements([
      <h1>hello</h1>,
      <h1 id="worldIDDDD">World</h1>
    ])).toEqual(true);

    expect(app.containsAnyMatchingElements([
      <h1 className='helloClass'>hello</h1>,
      <h1 id="worldIDDDD">World</h1>
    ])).toEqual(true);

    expect(app.containsAnyMatchingElements([
      <h1 className='helloClass'>hello</h1>,
      <span>haha</span>
    ])).toEqual(true);

    expect(app.containsAnyMatchingElements([
      <h1 className='helloClass'>hello</h1>,
      <span className='span'>haha</span>
    ])).toEqual(true);
  })
})

    contains总结：匹配规则越来越简单

    标题匹配规则检测节点个数
    contains严格匹配单个或者多个（多个节点相邻才可以匹配成功）containsMatchingElement最短匹配单个containsAllMatchingElements最短匹配多个（多个节点可以不相邻）containsAnyMatchingElements最短匹配多个（多个可以不相邻，多个节点一个满足就返回true）

    .equals(node)

    返回布尔值：表示当前渲染树的根节点是否和传入的相同，忽略未定义的属性。

    举个?

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div>
        <h1 className='helloClass'>hello</h1>
        {/* <h1 id="worldID">World</h1>
        <span className="spanClass">ya</span>
        <span>haha</span>
        <span fo="heheKey">hehe</span>
        <MyCom /> */}
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.equals(<div><h1 className='helloClass'>hello</h1></div>)).toEqual(true)
    expect(app.equals(<div><h1>hello</h1></div>)).toEqual(false)
    expect(app.equals(<h1 className='helloClass'>hello</h1>)).toEqual(false)
    expect(app.equals(<div></div>)).toEqual(false)
  })
})

    注意：当组件中注释部分解注释的时候测试不通过

    .matchesElement(node) => Boolean

    当前node是存在当前浅渲染树中。

    举个?

    // 待测试的组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div>
        <h1 className='helloClass'>hello</h1>
        {/* <h1 id="worldID">World</h1>
        <span className="spanClass">ya</span>
        <span>haha</span>
        <span fo="heheKey">hehe</span>
        <MyCom /> */}
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.matchesElement(<div><h1 className='helloClass'>hello</h1></div>)).toEqual(true)
    expect(app.matchesElement(<div><h1>hello</h1></div>)).toEqual(true)
    expect(app.matchesElement(<h1>hello</h1>)).toEqual(false)
    expect(app.matchesElement(<div></div>)).toEqual(false)
  })
})

    注意：当组件注释部分解注释时，测试不通过

    标题匹配规则
    equals严格匹配matchesElement最短匹配

    但是二者对与嵌套来说都是严格匹配。

    .hasClass(className) => Boolean

    是否有这个className

    举个?

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div>
        <h1 className='helloClass'>hello</h1>
        <h1 id="worldID" className='worldClass'>World</h1>
        <span className="spanClass">ya</span>
        <span>haha</span>
        <span fo="heheKey">hehe</span>
        <MyCom />
      </div>
    )
  }
}
export default App;

// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find('h1').at(0).hasClass('helloClass')).toEqual(true);
    expect(app.find('#worldID').hasClass('worldClass')).toEqual(true);
  })
})

    .is(selector) => Boolean

    返回单个包装节点是否与提供的选择器匹配。它必须是单节点包装器。

    举个?

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <h1 className='helloClass'>hello</h1>
    )
  }
}
export default App;

// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.is('.helloClass')).toEqual(true);
    expect(app.is('h1')).toEqual(true);
  })
})

    再举个?

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div>
        <h1 className='helloClass'>hello</h1>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.is('.helloClass')).toEqual(false);
    expect(app.is('h1')).toEqual(false);
    expect(app.is('div')).toEqual(true);
  })
})

    .exists() => Boolean

    当前节点是否存在

    举个?

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div>
        <h1 className='helloClass'>hello</h1>
        <h1 id="worldID" className='worldClass'>World</h1>
        <span className="spanClass">ya</span>
        <span>haha</span>
        <span fo="heheKey">hehe</span>
        <MyCom />
      </div>
    )
  }
}
export default App;

// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.exists('.helloClass')).toEqual(true);
    expect(app.find('#worldID').exists()).toEqual(true);
  })
})

    .not(selector) => ShallowWrapper

    删除当前wrapper中与所提供的选择器匹配的节点。 (与 .filter()作用相反)

    举个?

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div>
        <h1 className='helloClass'>hello</h1>
        <h1 id="worldID" className='worldClass'>World</h1>
        <span className="spanClass">ya</span>
        <span>haha</span>
        <span fo="heheKey">hehe</span>
        <MyCom />
      </div>
    )
  }
}
export default App;
//测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find('h1').not('.helloClass').text()).toBe('World')
  })
})

    .children() => ShallowWrapper

    获取当前 wrapper 中所有子节点的 wrapper.

    ???

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div>
        <h1 className='helloClass'>hello</h1>
        <h1 id="worldID" className='worldClass'>World</h1>
        <span className="spanClass">ya</span>
        <span>haha</span>
        <span fo="heheKey">hehe</span>
        <MyCom />
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find('div').children()).toHaveLength(6)
    expect(app.find('h1').children()).toHaveLength(2)
    expect(app.find('h1').children().at(0).text()).toBe('hello')
    expect(app.find('h1').children().at(1).text()).toBe('World')
  })
})

    .childAt(index) => ShallowWrapper

    返回具有指定索引的子元素的 wrapper

    ???

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div>
        <h1 className='helloClass'>hello</h1>
        <h1 id="worldID" className='worldClass'>World</h1>
        <span className="spanClass">ya</span>
        <span>haha</span>
        <span fo="heheKey">hehe</span>
        <MyCom />
      </div>
    )
  }
}
export default App;
//测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find('div').childAt(0).text()).toBe('hello')
    // expect(app.find('h1').childAt(1)).toBe('World')
    //“childAt” is meant to be run on 1 node. 2 found instead.
  })
})

    .parents() => ShallowWrapper

    获取当前节点的所有父级（祖先）

    ???

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div>
        <h1>
          <p>haha</p>
        </h1>
        <span>xixi</span>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find('p').parents()).toHaveLength(2)
    expect(app.find('span').parents()).toHaveLength(1)
  })
})

    .parent() => ShallowWrapper

    获取当前节点的直接父级

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div>
        <h1>
          <p>haha</p>
        </h1>
        <span>xixi</span>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find('p').parent()).toHaveLength(1)
    expect(app.find('span').parent()).toHaveLength(1)
  })
})

    .closest(selector) => ShallowWrapper

    从自身开始向上遍历，返回与当前选择器匹配的节点。必须是单节点包装器。

    ???

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <span className='calss1'>
        <h1>
          <p>haha</p>
        </h1>
        <span>xixi</span>
        {/* <p className='class2'>hehe</p> */}
      </span>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find('p').closest('.calss1').children().at(1).text()).toBe('xixi')
  })
})

    当组件中注释部分被解注释的时候，会报错：

    Jest+Enzyme进行React测试--环境搭建+Enzyme基础知识介绍

    应该保证查找节点(p)是单一节点。

    .shallow([options]) => ShallowWrapper

    浅渲染当前组件，生成虚拟DOM。

    .render() => CheerioWrapper

    返回当前节点的子树的CheerioWrapper

    .unmount() => ShallowWrapper

    一种卸载组件的方法。这可用于模拟经历卸载/安装生命周期的组件。

    .text() => String

    返回当前渲染树中文本节点的字符串表示形式。

    .html() => String

    返回当前节点的静态HTML呈现

    ???

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <span className='calss1'>
        <h1>
          <p>haha</p>
        </h1>
        <span>xixi</span>
        <p className='class2'>hehe</p>
      </span>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    console.log(app.find('.class2').html())
  })
})

    测试结果：

    Jest+Enzyme进行React测试--环境搭建+Enzyme基础知识介绍

    .get(index) => ReactElement

    返回给出索引的节点 ReactElement

    ???

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <h1>
          <p>haha</p>
        </h1>
        <span foo='foo-data'>xixi</span>
        <p className='class2'>hehe</p>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find('div').children().get(1).props.foo).toBe('foo-data')
  })
})

    可用于测试props参数。

    .at(index) => ShallowWrapper

    根据索引返回节点。

    ???

    // 待测试的组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <h1>
          <p>haha</p>
        </h1>
        <span foo='foo-data'>xixi</span>
        <p className='class2'>hehe</p>
      </div>
    )
  }
}
export default App;

// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find('p')
    .at(0)
    .text()).toBe('haha')
  })
})
// 测试通过

    .first() => ShallowWrapper

    返回当前第一个节点 wrapper

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <h1>
          <p>haha</p>
        </h1>
        <span foo='foo-data'>xixi</span>
        <p className='class2'>hehe</p>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find('p')
    .first()
    .text()).toBe('haha')
  })
})

    .last() => ShallowWrapper

    返回当前最后一个节点 wrapper

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <h1>
          <p>haha</p>
        </h1>
        <span foo='foo-data'>xixi</span>
        <p className='class2'>hehe</p>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find('p')
    .last()
    .text()).toBe('hehe')
  })
})

    .state([key]) => Any

    返回根组件的状态，只能应用于跟组件，如果在find的某个节点上使用会报错。 ShallowWrapper::state() can only be called on the root

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  constructor(props) {
    super(props);
    this.state = {
      name: 'jerry',
      age: 23
    }
  }
  render() {
    return (
      <div className='calss1'>
        <h1>
          <p>haha</p>
          <span>enen</span>
        </h1>
        <span foo='foo-data'>xixi</span>
        <p className='class2'>hehe</p>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.state('name')).toBe('jerry')
  })
})

    .context([key]) => Any

    返回根组件的上下文环境

    .props() => Object

    返回当前节点的 props

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <h1>
          <p>haha</p>
          <span>enen</span>
        </h1>
        <span foo='foo-data'>xixi</span>
        <p className='class2'>hehe</p>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    console.log(app.find("span").at(1).props());
    // { foo: 'foo-data', children: 'xixi' }
  })
})

    .prop(key) => Any

    返回当前节点props的某个(key)属性的值

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <h1>
          <p>haha</p>
          <span>enen</span>
        </h1>
        <span foo='foo-data'>xixi</span>
        <p className='class2'>hehe</p>
      </div>
    )
  }
}
export default App;

// 测试代码 
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find("span").at(1).prop('foo')).toBe('foo-data');
  })
})

    .key() => String

    返回当前节点的键（key）

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <h1 key='h1Key'>
          <p>haha</p>
          <span>enen</span>
        </h1>
        <span foo='foo-data'>xixi</span>
        <p className='class2'>hehe</p>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.find("h1").key()).toBe('h1Key');
  })
})

    .simulate(event[, data]) => ShallowWrapper

    模拟当前节点上的事件

    ???

    当前存在如下组件：

    import React, { Component } from 'react';
class App extends Component {
  constructor(props) {
    super(props);
    this.state = {
      count: 0
    }
  }
  handleClick = () => {
    this.setState({
      count: this.state.count + 1
    })
  }
  render() {
    return (
      <div className='calss1'>
        <button onClick={this.handleClick}>increase</button>
      </div>
    )
  }
}
export default App;

    我们需要测试的内容有：

    1. 点击increase按钮触发点击事件---simulate
    2. 测试点击事件后状态中count是否增1
    // 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.state("count")).toBe(0)
    const btn = app.find('button');
    btn.simulate('click');
    expect(app.state('count')).toBe(1)
  })
})

    .setState(nextState) => ShallowWrapper

    手动setState更新根组件状态

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  constructor(props) {
    super(props);
    this.state = {
      count: 0
    }
  }
  handleClick = () => {
    this.setState({
      count: this.state.count + 1
    })
  }
  render() {
    return (
      <div className='calss1'>
        <button onClick={this.handleClick}>increase</button>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App />);
    expect(app.state('count')).toBe(0);
    app.setState({count:5})
    expect(app.state('count')).toBe(5)
  })
})

    .setProps(nextProps) => ShallowWrapper

    手动更新根组件的props

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <p>hi:{this.props.name}</p>
      </div>
    )
  }
}
export default App;

// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App name='jerry' />);
    expect(app.find('p').text()).toBe('hi:jerry');
    app.setProps({name:'tom'});
    expect(app.find('p').text()).toBe('hi:tom')
  })
})

    .setContext(context) => ShallowWrapper

    手动设置根组件的上下文

    .instance() => ReactComponent

    返回根组件的实例

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <p>hi:{this.props.name}</p>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App name='jerry' />);
    console.log(app.instance())
  })
})

    Jest+Enzyme进行React测试--环境搭建+Enzyme基础知识介绍

    注意：只能在根实例的包装器实例上调用。 在 React 16 及更高版本中，instance() 为无状态功能组件返回 null。

    .update() => ShallowWrapper

    在根组件实例上调用.forceUpdate()

    .debug() => String

    返回当前浅渲染树的字符串表示形式，以便进行调试

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <p>hi:{this.props.name}</p>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App name='jerry' />);
    console.log(app.debug())
  })
})

    Jest+Enzyme进行React测试--环境搭建+Enzyme基础知识介绍

    .type() => String|Function

    返回包装器的当前节点的类型。

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <p>hi:{this.props.name}</p>
      </div>
    )
  }
}
export default App;
// 测试组件
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App name='jerry' />);
    expect(app.find('p').type()).toBe("p")
    expect(app.find('div').type()).toBe('div')
  })
})

    .name() => String

    返回当前节点的名称

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <p>hi:{this.props.name}</p>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App name='jerry' />);
    expect(app.find('p').name()).toBe("p")
    expect(app.find('div').name()).toBe('div')
  })
})

    .forEach(fn) => ShallowWrapper

    迭代当前的每个节点并执行提供的函数

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <div className="foo bax" />
        <div className="foo bar" />
        <div className="foo baz" />
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App name='jerry' />);
    const wrappers = app.find('.calss1').children();
    wrappers.forEach(e=>{
      expect(e.hasClass('foo')).toEqual(true);
    })
  })
})

    .map(fn) => Array

    将当前的节点数组映射到另一个数组

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <div className="foo bax" >a</div>
        <div className="foo bar" >b</div>
        <div className="foo baz bar" >c</div>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App name='jerry' />);
    const wrappers = app.find('.calss1').children();
    const map_wrappers = wrappers.map(e => e.hasClass('bar'));
    expect(map_wrappers).toEqual([false, true, true]);

    const text_wrappers = wrappers.map(e=>e.text());
    expect(text_wrappers).toEqual(['a','b','c'])
  })
})

    .reduce(fn[, initialValue]) => Any

    将提供的减少函数应用于包装器中的每个节点以减少到单个值。每个节点作为一个 ShallowWrapper 传入，并从左到右进行处理。

    1. function:为集合中的每个节点运行的归约函数，具有以下参数：
      • value：上次调用此函数返回的值
      • node：正在处理的节点wrapper
      • index：正在处理的节点索引
    2. initialValue:如果提供，这将作为第一个参数传入减少函数的第一次调用。 如果省略，将提供第一个节点，迭代将从集合中的第二个节点开始。

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <div className="foo" count={2}>a</div>
        <div className="foo" count={12}>b</div>
        <div className="foo" count={14}>c</div>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App name='jerry' />);
    const wrappers = app.find('.foo');
    const totalCount = wrappers.reduce((count, n) => count + n.prop('count'), 0);

    expect(totalCount).toEqual(28);
    const totalCount1 = wrappers.reduce((count, n) => count + n.prop('count'));
    expect(totalCount1).toEqual("[object Object]1214")

  })
})

    .reduceRight(fn[, initialValue]) => Any

    将当前节点数组从右到左减少为一个值。reduce为从左到右，这个为从右到左。

    .slice([begin[, end]]) => ShallowWrapper

    根据Array的slice的规则返回具有原始包装器的节点的子集的新包装器。

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <div className="foo" count={2}>a</div>
        <div className="foo" count={12}>b</div>
        <div className="foo" count={14}>c</div>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App name='jerry' />);
    const wrappers = app.find('.foo');
    const slice_wrapper = wrappers.slice(1,2);
    const text = slice_wrapper.map(e=>e.text())
    expect(text).toEqual(['b'])
  })
})

    .tap(intercepter) => Self

    点击wrapper方法链。有助于调试。

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <div className="foo" count={2}>a</div>
        <div className="foo" count={12}>b</div>
        <div className="foo" count={14}>c</div>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App name='jerry' />);
    const wrappers = app.find('.foo');
    
    const result= wrappers.tap(n=>console.log(n.debug())).map(n=>n.text());
    expect(result).toEqual(['a','b','c'])
  })
})

    Jest+Enzyme进行React测试--环境搭建+Enzyme基础知识介绍

    .some(selector) => Boolean

    返回渲染树中是否有节点与提供的选择器匹配。

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <div className="foo" id='aId' count={2}>a</div>
        <div className="foo" count={12}>b</div>
        <div className="foo" count={14}>c</div>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App name='jerry' />);
    const wrappers = app.find('.foo');
    expect(wrappers.some('#aId')).toEqual(true)
  })
})

    .someWhere(predicate) => Boolean

    返回渲染树中是否有节点与提供的断言函数匹配。个人理解是some的函数表现形式，比如需要处理再进行断言的时候可以通过这种方式。

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <div className="foo bar" count={2}>a</div>
        <div className="foo" count={12}>b</div>
        <div className="foo" count={14}>c</div>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App name='jerry' />);
    const wrappers = app.find('.foo');
    expect(wrappers.someWhere(n => n.hasClass('bar'))).toEqual(true)
  })
})

    .every(selector) => Boolean

    返回渲染树中是否所有节点与提供的选择器匹配。

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <div className="foo bar" count={2}>a</div>
        <div className="foo boo" count={12}>b</div>
        <div className="foo aoo" count={14}>c</div>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App name='jerry' />);
    const wrappers = app.find('.foo');
    expect(wrappers.every('.bar')).toEqual(false);
    expect(wrappers.every('.boo')).toEqual(false);
    expect(wrappers.every('.foo')).toEqual(true);

  })
})

    .everyWhere(predicate) => Boolean

    返回是否所有节点都满足所提供的断言函数。

    ???

    // 待测试组件
import React, { Component } from 'react';
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <div className="foo bar" count={2}>a</div>
        <div className="foo boo" count={12}>b</div>
        <div className="foo aoo" count={14}>c</div>
      </div>
    )
  }
}
export default App;
// 测试代码
import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App name='jerry' />);
    const wrappers = app.find('.foo');
    expect(wrappers.everyWhere(n=>n.hasClass('bar'))).toEqual(false);
    expect(wrappers.everyWhere(n=>n.hasClass('boo'))).toEqual(false);
    expect(wrappers.everyWhere(n=>n.hasClass('foo'))).toEqual(true);

  })
})

    .dive([options]) => ShallowWrapper

    浅渲染当前wrapper的一个非DOM子元素，并在结果周围返回一个wrapper，必须是单节点包装器。

    ???

    // 待测试组件
import React, { Component } from 'react';
import MyCom from './MyCom'
class App extends Component {
  render() {
    return (
      <div className='calss1'>
        <div className="foo bar" count={2}>a</div>
        <MyCom />
      </div>
    )
  }
}
export default App;

// MyCom
import React, { Component } from 'react';
class MyCom extends Component {
  render() {
    return (
      <h1>xixi</h1>
    )
  }
}
export default MyCom;

// 测试代码

import React from 'react';
import App from '../src/App';
import { shallow } from 'enzyme'

describe('component APP test', () => {
  it('测试hello world', () => {
    const app = shallow(<App name='jerry' />);
    const wrapper = app.find('MyCom');
    expect(wrapper.text()).toBe('<MyCom />');
    // expect(wrapper.find('h1').text()).toBe('xixi')
    // Method “text” is meant to be run on 1 node. 0 found instead. 
    expect(wrapper.dive().find('h1').text()).toBe('xixi')
  })
})

    只能在单个非 DOM 组件元素节点的包装器上调用，否则会抛出错误。 如果您必须对具有多个子节点的包装器进行浅包装，请使用 .shallow()。

    我所理解就是shallow不能渲染出来子组件，所以就不能查找到子组件中的内容，通过dive()可以实现。


    起源地下载网 » Jest+Enzyme进行React测试--环境搭建+Enzyme基础知识介绍

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