赛普拉斯测试中如何实现拖放？

Question

我正在努力使用Cypress和Angular Material拖放来测试拖放。因此，目标是将“开始工作”从Todo转移到Done。我创建了以下测试，这应该使您可以轻松重现：

您可以在此处玩Stackblitz 。

describe('Trying to implement drag-n-drop', () => {

    before(() => {
        Cypress.config('baseUrl', null);

        cy.viewport(1000, 600);
        cy.visit('https://angular-oxkc7l-zirwfs.stackblitz.io')
        .url().should('contain', 'angular')
        .get('h2').should('contain', 'To do');
    });

    it('Should work, based on this https://stackoverflow.com/a/54119137/3694288', () => {

        const dataTransfer = new DataTransfer;

        cy.get('#cdk-drop-list-0 > :nth-child(1)')
            .trigger('dragstart', { dataTransfer });

        cy.get('#cdk-drop-list-1')
            .trigger('drop', { dataTransfer });

        cy.get('#cdk-drop-list-0 > :nth-child(1)')
            .trigger('dragend');

        cy.get('#cdk-drop-list-1').should('contain', 'Get to work');
    });


    it('Should work, with this library https://github.com/4teamwork/cypress-drag-drop', () => {
        cy.get('#cdk-drop-list-0 > :nth-child(1)')
            .drag('#cdk-drop-list-1');

        cy.get('#cdk-drop-list-1').should('contain', 'Get to work');
    });

});

运行上述测试的结果如下所示：

这是开发解决方案的仓库。

谢谢您的帮助。

触发事件，使用chrome调试器发现：

项目

• 指针指向
• 指针输入
• 鼠标移到
• 按下鼠标
• 指针移动
• 鼠标移动
• 指针
• 指针离开
• 鼠标移出
• 鼠标离开

拖放区

• 指针指向
• 指针输入
• 鼠标移到
• 指针移动
• 鼠标移动
• 指针离开
• 鼠标移出
• 鼠标离开

解

在@Richard Matsen出色的答案之后，我最终将他的答案添加为自定义命令。解决方案看起来像这样

support / drag-support.ts

export function drag(dragSelector: string, dropSelector: string) {
    // Based on this answer: /sf/answers/3880589261/
    cy.get(dragSelector).should('exist')
      .get(dropSelector).should('exist');

      const draggable = Cypress.$(dragSelector)[0]; // Pick up this
      const droppable = Cypress.$(dropSelector)[0]; // Drop over this

      const coords = droppable.getBoundingClientRect();
      draggable.dispatchEvent(<any>new MouseEvent('mousedown'));
      draggable.dispatchEvent(<any>new MouseEvent('mousemove', {clientX: 10, clientY: 0}));
      draggable.dispatchEvent(<any>new MouseEvent('mousemove', {
          // I had to add (as any here --> maybe this can help solve the issue??)
          clientX: coords.left + 10,
          clientY: coords.top + 10  // A few extra pixels to get the ordering right
      }));
      draggable.dispatchEvent(new MouseEvent('mouseup'));
      return cy.get(dropSelector);
}

support / commands.ts

// Add typings for the custom command
declare global {
    namespace Cypress {
        interface Chainable {
            drag: (dragSelector: string, dropSelector: string) => Chainable;
        }
    }
}
// Finally add the custom command
Cypress.Commands.add('drag', drag);

在规格文件中

it(' Thx to Stackoverflow, drag and drop support now works ', () => {
   cy.drag('#cdk-drop-list-0 > :nth-child(1)', '#cdk-drop-list-1')
   .should('contain', 'Get to work');
});

一个小字，因为我很高兴它终于可以了

CI

现在，它也可以在CI（和本地电子）中使用。经过CircleCI 2.0测试。

Answer 1

我已经写了一个关于如何实现拖放的小例子。

它通过添加如下dragTo命令来工作：

/// <reference types="cypress"/>

it('works', () => {
  cy.visit('https://angular-oxkc7l-zirwfs.stackblitz.io/')
  cy.contains('To do', { timeout: 15000 }) // ensure page is loaded -__-

  const item = '.example-box:not(.cdk-drag-placeholder)'

  cy.get('#cdk-drop-list-1').children(item).should('have.length', 5)

  cy.get('.example-box:contains("Get to work")').dragTo('.example-box:contains("Get up")')
  cy.get('#cdk-drop-list-1').children(item).should('have.length', 6)

  // interpolates 10 extra mousemove events on the way
  cy.get('#cdk-drop-list-0').dragTo('#cdk-drop-list-1', { steps: 10 })
  cy.get('#cdk-drop-list-1').children(item).should('have.length', 7)

  // sets steps >= 10
  cy.get('#cdk-drop-list-0').dragTo('#cdk-drop-list-1', { smooth: true })
  cy.get('#cdk-drop-list-1').children(item).should('have.length', 8)

  cy.get('#cdk-drop-list-0').dragTo('#cdk-drop-list-1')
  cy.get('#cdk-drop-list-1').children(item).should('have.length', 9)
})

要添加它，请尝试将其放入support/index.js或粘贴到规范文件的底部（警告：代码质量差）：

const getCoords = ($el) => {
  const domRect = $el[0].getBoundingClientRect()
  const coords = { x: domRect.left + (domRect.width / 2 || 0), y: domRect.top + (domRect.height / 2 || 0) }

  return coords
}

const dragTo = (subject, to, opts) => {

  opts = Cypress._.defaults(opts, {
    // delay inbetween steps
    delay: 0,
    // interpolation between coords
    steps: 0,
    // >=10 steps
    smooth: false,
  })

  if (opts.smooth) {
    opts.steps = Math.max(opts.steps, 10)
  }

  const win = subject[0].ownerDocument.defaultView

  const elFromCoords = (coords) => win.document.elementFromPoint(coords.x, coords.y)
  const winMouseEvent = win.MouseEvent

  const send = (type, coords, el) => {

    el = el || elFromCoords(coords)

    el.dispatchEvent(
      new winMouseEvent(type, Object.assign({}, { clientX: coords.x, clientY: coords.y }, { bubbles: true, cancelable: true }))
    )
  }

  const toSel = to

  function drag (from, to, steps = 1) {

    const fromEl = elFromCoords(from)

    const _log = Cypress.log({
      $el: fromEl,
      name: 'drag to',
      message: toSel,
    })

    _log.snapshot('before', { next: 'after', at: 0 })

    _log.set({ coords: to })

    send('mouseover', from, fromEl)
    send('mousedown', from, fromEl)

    cy.then(() => {
      return Cypress.Promise.try(() => {

        if (steps > 0) {

          const dx = (to.x - from.x) / steps
          const dy = (to.y - from.y) / steps

          return Cypress.Promise.map(Array(steps).fill(), (v, i) => {
            i = steps - 1 - i

            let _to = {
              x: from.x + dx * (i),
              y: from.y + dy * (i),
            }

            send('mousemove', _to, fromEl)

            return Cypress.Promise.delay(opts.delay)

          }, { concurrency: 1 })
        }
      })
      .then(() => {

        send('mousemove', to, fromEl)
        send('mouseover', to)
        send('mousemove', to)
        send('mouseup', to)
        _log.snapshot('after', { at: 1 }).end()

      })

    })

  }

  const $el = subject
  const fromCoords = getCoords($el)
  const toCoords = getCoords(cy.$$(to))

  drag(fromCoords, toCoords, opts.steps)
}

Cypress.Commands.addAll(
  { prevSubject: 'element' },
  {
    dragTo,
  }
)

Answer 2

调度MouseEvents似乎是测试Angular Material拖放的唯一方法。

您还应该注意以下问题，该问题在量角器中进行了测试，但也适用于此赛普拉斯测试

在7.0.0-beta.2和7.0.0-rc.2之间进行CDK DragDrop回归：量角器测试停止工作＃13642，

似乎（出于更好的解释）在鼠标移动上需要额外轻推。

作为解决方法（量角器语法）给出的步骤，

private async dragAndDrop ( $element, $destination ) {
  await browser.actions().mouseMove( $element ).perform();
  await browser.actions().mouseDown( $element ).perform();
  await browser.actions().mouseMove( {x: 10, y: 0 } ).perform();
  await browser.actions().mouseMove( $destination ).perform();
  return browser.actions().mouseUp().perform();
}

可以翻译成赛普拉斯测试，我发现的最简单的形式是

it('works (simply)', () => {
  const draggable = Cypress.$('#cdk-drop-list-0 > :nth-child(1)')[0]  // Pick up this
  const droppable = Cypress.$('#cdk-drop-list-1 > :nth-child(4)')[0]  // Drop over this

  const coords = droppable.getBoundingClientRect()
  draggable.dispatchEvent(new MouseEvent('mousedown'));
  draggable.dispatchEvent(new MouseEvent('mousemove', {clientX: 10, clientY: 0}));
  draggable.dispatchEvent(new MouseEvent('mousemove', {
    clientX: coords.x+10,   
    clientY: coords.y+10  // A few extra pixels to get the ordering right
  }));
  draggable.dispatchEvent(new MouseEvent('mouseup'));

  cy.get('#cdk-drop-list-1').should('contain', 'Get to work');
  cy.get('#cdk-drop-list-1 > .cdk-drag').eq(3).should('contain', 'Get to work');

});

笔记

• 参考问题中的问题不仅限于量角器。如果mousemove在赛普拉斯测试中删除了第一个，它也会失败。
• 该cy.get(..).trigger()语法似乎不适用于Angular，但本机dispatchEvent()可以。
• 拖动到目标列表中的特定元素上（而不是仅拖放到列表中）可以在目标列表中进行精确定位。
• dragstart, dragend可能不适用于Angular Material，因为代码显示接收到的事件是类型CdkDragDrop而不是DataTransfer对象。
• 如果以异步方式获取内容，则可能必须从切换Cypress.$(...)到cy.get(...).then(el => {...})，以利用cypress在命令中的自动重试功能。
• 我必须添加10秒钟的超时时间才能访问Stackblitz网址。

异步列表获取

如果列表是在组件构建过程中由异步Angular服务（httpClient）获取的，请在测试中使用它

const draggable = Cypress.$('#cdk-drop-list-0 > :nth-child(1)')[0]

将不会起作用，因为只有在获取完成后，第n个孩子才会立即出现。

相反，您可以cy.get()用来提供重试，直到超时（默认为5秒）。

const draggable = Cypress.$('#cdk-drop-list-0 > :nth-child(1)')[0]

或者我更喜欢使用“ canary”测试来确保加载完成，例如

cy.get('#cdk-drop-list-0 > :nth-child(1)').then(el => {
  const draggable = el[0]  // Pick up this
  cy.get('#cdk-drop-list-1 > :nth-child(4)').then(el => {
    const droppable = el[0]  // Drop over this

    const coords = droppable.getBoundingClientRect()
    draggable.dispatchEvent(new MouseEvent('mousemove'));
    draggable.dispatchEvent(new MouseEvent('mousedown'));
    draggable.dispatchEvent(new MouseEvent('mousemove', {clientX: 10, clientY: 0}));
    draggable.dispatchEvent(new MouseEvent('mousemove', {clientX: coords.x+10, clientY: coords.y+10}));
    draggable.dispatchEvent(new MouseEvent('mouseup'));

  })

  cy.get('#cdk-drop-list-1').should('contain', 'Get to work');
  cy.get('#cdk-drop-list-1 > .cdk-drag').eq(3).should('contain', 'Get to work');
})

打字稿支持

警告-这是一种克服Typescript编译器问题的快速技巧，可以进行改进。

• 根据TypeScript错误中的MouseEvent强制MouseEvent转换<any>为不匹配签名

• 输入return getBoundingClientRect()到ClientRect，并使用left和top属性代替x和y。

before(() => {
  cy.get('#cdk-drop-list-0 > :nth-child(1)') // Canary - wait 5s for data
})

it('should...', () => {
  const draggable = Cypress.$('#cdk-drop-list-0 > :nth-child(1)')[0]  // Pick up this
  const droppable = Cypress.$('#cdk-drop-list-1 > :nth-child(4)')[0]  // Drop over this
  ...
})

Answer 3

经过一番努力，我成功地使拖放工作与此相关：

cy.get('.list .item')
      .contains(startpos)
      .trigger('dragstart', { dataTransfer: new DataTransfer });
cy.get('.list .item')
      .eq(endpos)
      .trigger('drop')
      .trigger('dragend');

非常容易使用。