specs/draggable.spec.jsx

/*eslint no-unused-vars:0, no-console:0*/
import React from 'react';
import ReactDOM from 'react-dom';
import TestUtils from 'react-dom/test-utils';
import ShallowRenderer from 'react-test-renderer/shallow';
import Draggable, {DraggableCore} from '../lib/Draggable';
import FrameComponent from 'react-frame-component';
import assert from 'assert';
import _ from 'lodash';
import {getPrefix, browserPrefixToKey, browserPrefixToStyle} from '../lib/utils/getPrefix';
const transformStyle = browserPrefixToStyle('transform', getPrefix('transform'));
const transformKey = browserPrefixToKey('transform', getPrefix('transform'));
const userSelectStyle = browserPrefixToStyle('user-select', getPrefix('user-select'));

describe('react-draggable', function () {
  var drag;

  // Remove body margin so offsetParent calculations work properly
  beforeAll(function() {
    const styleNode = document.createElement('style');
    // browser detection (based on prototype.js)
    const styleText = document.createTextNode('body {margin: 0;}');
    styleNode.appendChild(styleText);
    document.getElementsByTagName('head')[0].appendChild(styleNode);
  });

  beforeEach(function() {
    spyOn(console, 'error');
  });

  afterEach(function() {
    try {
      TestUtils.Simulate.mouseUp(ReactDOM.findDOMNode(drag)); // reset user-select
      ReactDOM.unmountComponentAtNode(ReactDOM.findDOMNode(drag).parentNode);
    } catch(e) { return; }
  });

  describe('props', function () {
    it('should have default properties', function () {
      drag = TestUtils.renderIntoDocument(<Draggable><div/></Draggable>);

      assert.equal(drag.props.axis, 'both');
      assert(drag.props.bounds == false);
      assert.equal(typeof drag.props.onStart, 'function');
      assert.equal(typeof drag.props.onDrag, 'function');
      assert.equal(typeof drag.props.onStop, 'function');
    });

    it('should pass style and className properly from child', function () {
      drag = (<Draggable><div className="foo" style={{color: 'black'}}/></Draggable>);

      const node = renderToNode(drag);
      // Touch-action hack has been removed
      if ('touchAction' in document.body.style) {
        assert.equal(node.getAttribute('style').indexOf('touch-action: none'), -1);
      }
      assert(node.getAttribute('style').indexOf('color: black') >= 0);
      assert(new RegExp(transformStyle + ': translate\\(0px(?:, 0px)?\\)').test(node.getAttribute('style')));
      assert.equal(node.getAttribute('class'), 'foo react-draggable');
    });

    it('should set the appropriate custom className when dragging or dragged', function () {
      drag = TestUtils.renderIntoDocument(
        <Draggable
          defaultClassName='foo'
          defaultClassNameDragging='bar'
          defaultClassNameDragged='baz'
        >
          <div/>
        </Draggable>
      );
      var node = ReactDOM.findDOMNode(drag);
      assert(node.getAttribute('class').indexOf('foo') >= 0);
      TestUtils.Simulate.mouseDown(node);
      assert(node.getAttribute('class').indexOf('bar') >= 0);
      TestUtils.Simulate.mouseUp(node);
      assert(node.getAttribute('class').indexOf('baz') >= 0);
    });

    // NOTE: this runs a shallow renderer, which DOES NOT actually render <DraggableCore>
    it('should pass handle on to <DraggableCore>', function () {
      drag = <Draggable handle=".foo"><div /></Draggable>;
      const renderer = new ShallowRenderer();
      renderer.render(drag);
      const output = renderer.getRenderOutput();

      const expected = (
        <DraggableCore handle=".foo">
          <div
            className="react-draggable"
            style={{
              [transformKey]: 'translate(0px, 0px)'
            }}
            transform={null} />
        </DraggableCore>
      );

      // Not easy to actually test equality here. The functions are bound as static props so we can't test those easily.
      const toOmit = ['onStart', 'onStop', 'onDrag', 'onMouseDown', 'children'];
      assert.deepEqual(
        _.omit(output.props, toOmit),
        _.omit(expected.props, toOmit)
      );
    });

    it('should honor props', function () {
      function handleStart() {}
      function handleDrag() {}
      function handleStop() {}

      drag = TestUtils.renderIntoDocument(
        <Draggable
          axis="y"
          handle=".handle"
          cancel=".cancel"
          grid={[10, 10]}
          onStart={handleStart}
          onDrag={handleDrag}
          onStop={handleStop}>
          <div className="foo bar">
            <div className="handle"/>
            <div className="cancel"/>
          </div>
        </Draggable>
      );

      assert.equal(drag.props.axis, 'y');
      assert.equal(drag.props.handle, '.handle');
      assert.equal(drag.props.cancel, '.cancel');
      assert(_.isEqual(drag.props.grid, [10, 10]));
      assert.equal(drag.props.onStart, handleStart);
      assert.equal(drag.props.onDrag, handleDrag);
      assert.equal(drag.props.onStop, handleStop);
    });

    it('should adjust draggable data output when `scale` prop supplied', function () {
      function onDrag(event, data) {
        assert.equal(data.x, 200);
        assert.equal(data.y, 200);
        assert.equal(data.deltaX, 200);
        assert.equal(data.deltaY, 200);
      }
      drag = TestUtils.renderIntoDocument(
        <Draggable
          scale={0.5}
          onDrag={onDrag}>
          <div />
        </Draggable>
      );

      simulateMovementFromTo(drag, 0, 0, 100, 100);
    });

    it('should throw when setting className', function () {
      drag = (<Draggable className="foo"><span /></Draggable>);

      TestUtils.renderIntoDocument(drag);

      expect(
        console.error.calls.argsFor(0)[0].replace('propType:', 'prop type:').split('\n')[0]
      ).toBe(
        'Warning: Failed prop type: Invalid prop className passed to Draggable - do not set this, set it on the child.'
      );
    });

    it('should throw when setting style', function () {
      drag = (<Draggable style={{color: 'red'}}><span /></Draggable>);

      TestUtils.renderIntoDocument(drag);

      expect(
        console.error.calls.argsFor(0)[0].replace('propType:', 'prop type:').split('\n')[0]
      ).toBe(
        'Warning: Failed prop type: Invalid prop style passed to Draggable - do not set this, set it on the child.'
      );
    });

    it('should throw when setting transform', function () {
      drag = (<Draggable transform="translate(100, 100)"><span /></Draggable>);

      TestUtils.renderIntoDocument(drag);

      expect(
        console.error.calls.argsFor(0)[0].replace('propType:', 'prop type:').split('\n')[0]
      ).toBe(
        'Warning: Failed prop type: Invalid prop transform passed to Draggable - do not set this, set it on the child.'
      );
    });

    it('should call onStart when dragging begins', function () {
      let called = false;
      drag = TestUtils.renderIntoDocument(
        <Draggable onStart={function () { called = true; }}>
          <div/>
        </Draggable>
      );

      TestUtils.Simulate.mouseDown(ReactDOM.findDOMNode(drag));
      assert.equal(called, true);
    });

    it('should call onStop when dragging ends', function () {
      let called = false;
      drag = TestUtils.renderIntoDocument(
        <Draggable onStop={function () { called = true; }}>
          <div/>
        </Draggable>
      );

      TestUtils.Simulate.mouseDown(ReactDOM.findDOMNode(drag));
      TestUtils.Simulate.mouseUp(ReactDOM.findDOMNode(drag));
      assert.equal(called, true);
    });

    it('should not call onStart when dragging begins and disabled', function () {
      let called = false;
      drag = TestUtils.renderIntoDocument(
        <Draggable onStart={function () { called = true; }} disabled={true}>
          <div/>
        </Draggable>
      );

      TestUtils.Simulate.mouseDown(ReactDOM.findDOMNode(drag));
      assert.equal(called, false);
    });

    it('should immediately call onStop if onDrag returns false', function () {
      let called = false;
      drag = TestUtils.renderIntoDocument(
        <Draggable onDrag={function () { return false; }} onStop={function () { called = true; }}>
          <div/>
        </Draggable>
      );

      TestUtils.Simulate.mouseDown(ReactDOM.findDOMNode(drag));
      assert.equal(called, false);
      mouseMove(10, 10);
      assert.equal(called, true);
      assert.equal(drag.state.x, 0);
      assert.equal(drag.state.y, 0);
    });

    it('should render with style translate() for DOM nodes', function () {
      let dragged = false;
      drag = TestUtils.renderIntoDocument(
        <Draggable onDrag={function() { dragged = true; }}>
          <div />
        </Draggable>
      );

      const node = ReactDOM.findDOMNode(drag);
      simulateMovementFromTo(drag, 0, 0, 100, 100);

      const style = node.getAttribute('style');
      assert.equal(dragged, true);
      assert(style.indexOf('transform: translate(100px, 100px);') >= 0);
    });

    it('should render with positionOffset set as string transform and handle subsequent translate() for DOM nodes', function () {
      let dragged = false;
      drag = TestUtils.renderIntoDocument(
        <Draggable positionOffset={{x: '10%', y: '10%'}} onDrag={function() { dragged = true; }}>
          <div />
        </Draggable>
      );

      const node = ReactDOM.findDOMNode(drag);
      simulateMovementFromTo(drag, 0, 0, 100, 100);

      const style = node.getAttribute('style');
      assert.equal(dragged, true);
      assert(style.indexOf('translate(10%, 10%) translate(100px, 100px);') >= 0);
    });

    it('should honor "x" axis', function () {
      let dragged = false;
      drag = TestUtils.renderIntoDocument(
        <Draggable onDrag={function() { dragged = true; }} axis="x">
          <div />
        </Draggable>
      );

      const node = ReactDOM.findDOMNode(drag);
      simulateMovementFromTo(drag, 0, 0, 100, 100);

      const style = node.getAttribute('style');
      assert.equal(dragged, true);
      assert(/transform: translate\(100px(?:, 0px)?\);/.test(style));
    });

    it('should honor "y" axis', function () {
      let dragged = false;
      drag = TestUtils.renderIntoDocument(
        <Draggable onDrag={function() { dragged = true; }} axis="y">
          <div />
        </Draggable>
      );

      const node = ReactDOM.findDOMNode(drag);
      simulateMovementFromTo(drag, 0, 0, 100, 100);

      const style = node.getAttribute('style');
      assert.equal(dragged, true);
      assert(style.indexOf('transform: translate(0px, 100px);') >= 0);
    });

    it('should honor "none" axis', function () {
      let dragged = false;
      drag = TestUtils.renderIntoDocument(
        <Draggable onDrag={function() { dragged = true; }} axis="none">
          <div />
        </Draggable>
      );

      const node = ReactDOM.findDOMNode(drag);
      simulateMovementFromTo(drag, 0, 0, 100, 100);

      const style = node.getAttribute('style');
      assert.equal(dragged, true);
      assert(/transform: translate\(0px(?:, 0px)?\);/.test(style));
    });

    it('should detect if an element is instanceof SVGElement and set state.isElementSVG to true', function() {
      drag = TestUtils.renderIntoDocument(
          <Draggable>
            <svg />
          </Draggable>
      );

      assert.equal(drag.state.isElementSVG, true);
    });

    it('should detect if an element is NOT an instanceof SVGElement and set state.isElementSVG to false', function() {
      drag = TestUtils.renderIntoDocument(
          <Draggable>
            <div />
          </Draggable>
      );

      assert.equal(drag.state.isElementSVG, false);
    });

    it('should render with transform translate() for SVG nodes', function () {
      drag = TestUtils.renderIntoDocument(
          <Draggable>
            <svg />
          </Draggable>
      );

      const node = ReactDOM.findDOMNode(drag);
      simulateMovementFromTo(drag, 0, 0, 100, 100);

      const transform = node.getAttribute('transform');
      assert(transform.indexOf('translate(100,100)') >= 0);
    });

    it('should add and remove transparent selection class', function () {
       drag = TestUtils.renderIntoDocument(
         <Draggable>
           <div />
         </Draggable>
       );

       const node = ReactDOM.findDOMNode(drag);

       assert(!document.body.classList.contains('react-draggable-transparent-selection'));
       TestUtils.Simulate.mouseDown(node, {clientX: 0, clientY: 0});
       assert(document.body.classList.contains('react-draggable-transparent-selection'));
       TestUtils.Simulate.mouseUp(node);
       assert(!document.body.classList.contains('react-draggable-transparent-selection'));
     });

    it('should not add and remove transparent selection class when disabled', function () {

      drag = TestUtils.renderIntoDocument(
        <Draggable enableUserSelectHack={false}>
          <div />
        </Draggable>
      );

      const node = ReactDOM.findDOMNode(drag);

      assert(!document.body.classList.contains('react-draggable-transparent-selection'));
      TestUtils.Simulate.mouseDown(node, {clientX: 0, clientY: 0});
      assert(!document.body.classList.contains('react-draggable-transparent-selection'));
      TestUtils.Simulate.mouseUp(node);
      assert(!document.body.classList.contains('react-draggable-transparent-selection'));
    });

    it('should not add and remove transparent selection class when onStart returns false', function () {
      function onStart() { return false; }

      drag = TestUtils.renderIntoDocument(
        <Draggable onStart={onStart}>
          <div />
        </Draggable>
      );

      const node = ReactDOM.findDOMNode(drag);

      assert(!document.body.classList.contains('react-draggable-transparent-selection'));
      TestUtils.Simulate.mouseDown(node, {clientX: 0, clientY: 0});
      assert(!document.body.classList.contains('react-draggable-transparent-selection'));
      TestUtils.Simulate.mouseUp(node);
      assert(!document.body.classList.contains('react-draggable-transparent-selection'));
    });

    it('should not defocus inputs when unmounting', function () {
      // Have only successfully gotten this to run on Chrome unfortunately, otherwise the initial
      // select does not work.
      // As of April 2020 we have verified this works in other browsers manually
      if (!/Chrome/.test(window.navigator.userAgent)) {
        return pending();
      }

      class TestCase extends React.Component {
        constructor() {
          super();
          this.state = {text: false};
        }
        render() {
          return (
            <div>
              <input type="text" onChange={(e) => this.setState({text: e.target.value})} size={5} />
              {!this.state.text && (
                <Draggable>
                  <div />
                </Draggable>
              )}
            </div>
          );
        }
      }

      drag = TestUtils.renderIntoDocument(<TestCase/>);
      const dragEl = ReactDOM.findDOMNode(drag);
      // Need to append to a real document to test focus/selection, can't just be a fragment
      document.body.appendChild(dragEl);
      const input = dragEl.querySelector('input');
      input.focus();

      assert.equal(window.getSelection().type, 'Caret', 'Element should be focused before draggable unmounts');
      TestUtils.Simulate.keyDown(input, {key: 'a', keyCode: 65, which: 65});
      assert.equal(window.getSelection().type, 'Caret', 'Element should be focused after draggable unmounts');
      document.body.removeChild(dragEl);
    });

    it('should be draggable when in an iframe', function (done) {
      let dragged = false;
      const dragElement = (
        <Draggable onDrag={function() { dragged = true; }}>
          <div />
        </Draggable>
      );
      const renderRoot = document.body.appendChild(document.createElement('div'));
      const ref = React.createRef();
      const frame = ReactDOM.render(<FrameComponent ref={ref}>{ dragElement }</FrameComponent>, renderRoot);

      setTimeout(function checkIframe() {
        const iframeDoc = ref.current?.contentDocument;
        if (!iframeDoc) return setTimeout(checkIframe, 50);
        const node = iframeDoc.querySelector('.react-draggable');
        if (!node) return setTimeout(checkIframe, 50);
        simulateMovementFromTo(node, 0, 0, 100, 100);

        const style = node.getAttribute('style');
        assert.equal(dragged, true);
        assert(style.indexOf('transform: translate(100px, 100px);') >= 0);

        renderRoot.parentNode.removeChild(renderRoot);
        done();
      }, 0);
    });

    it('should add and remove transparent selection class to iframe\'s body when in an iframe', function (done) {
      const dragElement = (
        <Draggable>
          <div />
        </Draggable>
      );
      const renderRoot = document.body.appendChild(document.createElement('div'));
      const ref = React.createRef();
      ReactDOM.render(<FrameComponent ref={ref}>{ dragElement }</FrameComponent>, renderRoot);

      setTimeout(function checkIframe() {
        const iframeDoc = ref.current?.contentDocument;
        if (!iframeDoc) return setTimeout(checkIframe, 50);
        const node = iframeDoc.querySelector('.react-draggable');
        if (!node) return setTimeout(checkIframe, 50);

        assert(!document.body.classList.contains('react-draggable-transparent-selection'));
        assert(!iframeDoc.body.classList.contains('react-draggable-transparent-selection'));
        TestUtils.Simulate.mouseDown(node, {clientX: 0, clientY: 0});
        assert(!document.body.classList.contains('react-draggable-transparent-selection'));
        assert(iframeDoc.body.classList.contains('react-draggable-transparent-selection'));
        TestUtils.Simulate.mouseUp(node);
        assert(!document.body.classList.contains('react-draggable-transparent-selection'));
        assert(!iframeDoc.body.classList.contains('react-draggable-transparent-selection'));

        renderRoot.parentNode.removeChild(renderRoot);
        done();
      }, 0);
    });
  });

  describe('interaction', function () {

    function mouseDownOn(drag, selector, shouldDrag) {
      resetDragging(drag);
      const node = ReactDOM.findDOMNode(drag).querySelector(selector);
      if (!node) throw new Error(`Selector not found: ${selector}`);
      TestUtils.Simulate.mouseDown(node);
      assert.equal(drag.state.dragging, shouldDrag);
    }

    function resetDragging(drag) {
      TestUtils.Simulate.mouseUp(ReactDOM.findDOMNode(drag));
      assert.equal(drag.state.dragging, false);
    }

    it('should initialize dragging onmousedown', function () {
      drag = TestUtils.renderIntoDocument(<Draggable><div/></Draggable>);

      TestUtils.Simulate.mouseDown(ReactDOM.findDOMNode(drag));
      assert.equal(drag.state.dragging, true);
    });

    it('should only initialize dragging onmousedown of handle', function () {
      drag = TestUtils.renderIntoDocument(
        <Draggable handle=".handle">
          <div>
            <div className="handle">Handle</div>
            <div className="content">Lorem ipsum...</div>
          </div>
        </Draggable>
      );

      mouseDownOn(drag, '.content', false);
      mouseDownOn(drag, '.handle', true);
    });

    it('should only initialize dragging onmousedown of handle, even if children fire event', function () {
      drag = TestUtils.renderIntoDocument(
        <Draggable handle=".handle">
          <div>
            <div className="handle">
              <div><span><div className="deep">Handle</div></span></div>
            </div>
            <div className="content">Lorem ipsum...</div>
          </div>
        </Draggable>
      );

      mouseDownOn(drag, '.content', false);
      mouseDownOn(drag, '.deep', true);
      mouseDownOn(drag, '.handle > div', true);
      mouseDownOn(drag, '.handle span', true);
      mouseDownOn(drag, '.handle', true);
    });

    it('should not initialize dragging onmousedown of cancel', function () {
      drag = TestUtils.renderIntoDocument(
        <Draggable cancel=".cancel">
          <div>
            <div className="cancel">Cancel</div>
            <div className="content">Lorem ipsum...</div>
          </div>
        </Draggable>
      );

      mouseDownOn(drag, '.cancel', false);
      mouseDownOn(drag, '.content', true);
    });

    it('should not initialize dragging onmousedown of handle, even if children fire event', function () {
      drag = TestUtils.renderIntoDocument(
        <Draggable cancel=".cancel">
          <div>
            <div className="cancel">
              <div><span><div className="deep">Cancel</div></span></div>
            </div>
            <div className="content">Lorem ipsum...</div>
          </div>
        </Draggable>
      );

      mouseDownOn(drag, '.content', true);
      mouseDownOn(drag, '.deep', false);
      mouseDownOn(drag, '.cancel > div', false);
      mouseDownOn(drag, '.cancel span', false);
      mouseDownOn(drag, '.cancel', false);
    });

    it('should discontinue dragging onmouseup', function () {
      drag = TestUtils.renderIntoDocument(<Draggable><div/></Draggable>);

      TestUtils.Simulate.mouseDown(ReactDOM.findDOMNode(drag));
      assert.equal(drag.state.dragging, true);

      resetDragging(drag);
    });

    it('should initialize dragging ontouchstart', function () {
      drag = TestUtils.renderIntoDocument(<Draggable><div/></Draggable>);

      // Need to dispatch this ourselves as there is no onTouchStart handler (due to passive)
      // so TestUtils.Simulate will not work
      const e = new Event('touchstart');
      ReactDOM.findDOMNode(drag).dispatchEvent(e);
      assert.equal(drag.state.dragging, true);
    });

    it('should call preventDefault on touchStart event', function () {
      drag = TestUtils.renderIntoDocument(<Draggable><div/></Draggable>);

      const e = new Event('touchstart');
      // Oddly `e.defaultPrevented` is not changing here. Maybe because we're not mounted to a real doc?
      let pdCalled = false;
      e.preventDefault = function() { pdCalled = true; };
      ReactDOM.findDOMNode(drag).dispatchEvent(e);
      assert(pdCalled);
      assert.equal(drag.state.dragging, true);
    });

    it('should not call preventDefault on touchStart event if not on handle', function () {
      drag = TestUtils.renderIntoDocument(
        <Draggable handle=".handle">
          <div>
            <div className="handle">
              <div><span><div className="deep">Handle</div></span></div>
            </div>
            <div className="content">Lorem ipsum...</div>
          </div>
        </Draggable>
      );

      const e = new Event('touchstart');
      let pdCalled = false;
      e.preventDefault = function() { pdCalled = true; };
      ReactDOM.findDOMNode(drag).querySelector('.content').dispatchEvent(e);
      assert(!pdCalled);
      assert(drag.state.dragging !== true);
    });

    it('should modulate position on scroll', function (done) {
      let dragCalled = false;

      function onDrag(e, coreEvent) {
        assert.equal(Math.round(coreEvent.deltaY), 500);
        dragCalled = true;
      }
      drag = TestUtils.renderIntoDocument(<Draggable onDrag={onDrag}><div/></Draggable>);
      const node = ReactDOM.findDOMNode(drag);

      // Create a container we can scroll. I'm doing it this way so we can still access <Draggable>.
      // Enzyme (airbnb project) would make this a lot easier.
      const fragment = fragmentFromString(`
        <div style="overflow: auto; height: 100px;">
          <div style="height: 10000px; position: relative;">
          </div>
        </div>
      `);
      transplantNodeInto(node, fragment, (f) => f.children[0]);

      TestUtils.Simulate.mouseDown(node, {clientX: 0, clientY: 0});
      assert.equal(drag.state.dragging, true);

      // Scroll the inner container & trigger a scroll
      fragment.scrollTop = 500;
      mouseMove(0, 0);
      TestUtils.Simulate.mouseUp(node);
      setTimeout(function() {
        assert.equal(drag.state.dragging, false);
        assert.equal(dragCalled, true);
        assert.equal(drag.state.y, 500);
        // Cleanup
        document.body.removeChild(fragment);
        done();
      }, 50);

    });

    it('should respect offsetParent on nested div scroll', function (done) {
      let dragCalled = false;
      function onDrag(e, coreEvent) {
        dragCalled = true;
        // Because the offsetParent is the body, we technically haven't moved at all relative to it
        assert.equal(coreEvent.deltaY, 0);
      }
      drag = TestUtils.renderIntoDocument(<Draggable onDrag={onDrag} offsetParent={document.body}><div/></Draggable>);
      const node = ReactDOM.findDOMNode(drag);

      // Create a container we can scroll. I'm doing it this way so we can still access <Draggable>.
      // Enzyme (airbnb project) would make this a lot easier.
      const fragment = fragmentFromString(`
        <div style="overflow: auto; height: 100px;">
          <div style="height: 10000px; position: relative;">
          </div>
        </div>
      `);
      transplantNodeInto(node, fragment, (f) => f.children[0]);

      TestUtils.Simulate.mouseDown(node, {clientX: 0, clientY: 0});
      fragment.scrollTop = 500;

      mouseMove(0, 0);
      TestUtils.Simulate.mouseUp(node);
      setTimeout(function() {
        assert(dragCalled);
        // Cleanup
        document.body.removeChild(fragment);
        done();
      }, 50);
    });
  });

  describe('draggable callbacks', function () {
    it('should call back on drag', function (done) {
      function onDrag(event, data) {
        assert.equal(data.x, 100);
        assert.equal(data.y, 100);
        assert.equal(data.deltaX, 100);
        assert.equal(data.deltaY, 100);
        assert.equal(data.node, ReactDOM.findDOMNode(drag));
        done();
      }
      drag = TestUtils.renderIntoDocument(
        <Draggable onDrag={onDrag}>
          <div />
        </Draggable>
      );

      // (element, fromX, fromY, toX, toY)
      simulateMovementFromTo(drag, 0, 0, 100, 100);
    });

    it('should call back with correct dom node with nodeRef', function (done) {
      function onDrag(event, data) {
        // Being tricky here and installing the ref on the inner child, to ensure it's working
        // and not just falling back on ReactDOM.findDOMNode()
        assert.equal(data.node, ReactDOM.findDOMNode(drag).firstChild);
        done();
      }
      const nodeRef = React.createRef();
      drag = TestUtils.renderIntoDocument(
        <Draggable onDrag={onDrag} nodeRef={nodeRef}>
          <span>
            <div ref={nodeRef} />
          </span>
        </Draggable>
      );

      // (element, fromX, fromY, toX, toY)
      simulateMovementFromTo(drag, 0, 0, 100, 100);
    });

    it('should call back with correct dom node with nodeRef (forwardRef)', function (done) {

      const Component1 = React.forwardRef(function (props, ref) {
        return <div {...props} ref={ref}>Nested component</div>;
      });

      function onDrag(event, data) {
        assert.equal(data.node, ReactDOM.findDOMNode(drag));
        assert.equal(data.node.innerText, 'Nested component');
        done();
      }
      const nodeRef = React.createRef();
      drag = TestUtils.renderIntoDocument(
        <DraggableCore onDrag={onDrag} nodeRef={nodeRef}>
          <Component1 ref={nodeRef} />
        </DraggableCore>
      );

      // (element, fromX, fromY, toX, toY)
      simulateMovementFromTo(drag, 0, 0, 100, 100);
    });

    it('should call back on drag, with values within the defined bounds', function(done){
      function onDrag(event, data) {
        assert.equal(data.x, 90);
        assert.equal(data.y, 90);
        assert.equal(data.deltaX, 90);
        assert.equal(data.deltaY, 90);
        done();
      }
      drag = TestUtils.renderIntoDocument(
        <Draggable onDrag={onDrag} bounds={{left: 0, right: 90, top: 0, bottom: 90}}>
          <div />
        </Draggable>
      );

      // (element, fromX, fromY, toX, toY)
      simulateMovementFromTo(drag, 0, 0, 100, 100);

    });

    it('should call back with offset left/top, not client', function(done) {
      function onDrag(event, data) {
        assert.equal(data.x, 100);
        assert.equal(data.y, 100);
        assert.equal(data.deltaX, 100);
        assert.equal(data.deltaY, 100);
        done();
      }
      drag = TestUtils.renderIntoDocument(
        <Draggable onDrag={onDrag} >
          <div style={{position: 'relative', top: '200px', left: '200px'}} />
        </Draggable>
      );

      simulateMovementFromTo(drag, 200, 200, 300, 300);
    });

    it('should call back with correct position when parent element is 2x scaled', function(done) {
      function onDrag(event, data) {
        // visually it will look like 100, because parent is 2x scaled
        assert.equal(data.x, 50);
        assert.equal(data.y, 50);
        assert.equal(data.deltaX, 50);
        assert.equal(data.deltaY, 50);
        assert.equal(data.node, ReactDOM.findDOMNode(drag));
        done();
      }
      drag = TestUtils.renderIntoDocument(
        <Draggable onDrag={onDrag} scale={2}>
          <div />
        </Draggable>
      );

      // (element, fromX, fromY, toX, toY)
      simulateMovementFromTo(drag, 0, 0, 100, 100);
    });

    it('should call back with correct position when parent element is 0.5x scaled', function(done) {
      function onDrag(event, data) {
        // visually it will look like 100, because parent is 0.5x scaled
        assert.equal(data.x, 200);
        assert.equal(data.y, 200);
        assert.equal(data.deltaX, 200);
        assert.equal(data.deltaY, 200);
        assert.equal(data.node, ReactDOM.findDOMNode(drag));
        done();
      }
      drag = TestUtils.renderIntoDocument(
        <Draggable onDrag={onDrag} scale={0.5}>
          <div />
        </Draggable>
      );

      // (element, fromX, fromY, toX, toY)
      simulateMovementFromTo(drag, 0, 0, 100, 100);
    });

    it('should not throw an error if unmounted during a callback', function () {
      function App(props) {
        const [firstVisible, setFirstVisible] = React.useState(true);
        // Callback with ref to draggable
        const dragRef = React.useRef(null);
        props.draggableRefCb(dragRef);
        return (
          <div className="App">
            <button onClick={() => setFirstVisible(true)}>Show draggables</button>

            {firstVisible && (
              <Draggable onStop={() => setFirstVisible(false)} ref={dragRef}>
                <h2>1. Drag me!</h2>
              </Draggable>
            )}
          </div>
        );
      }
      let dragRef;
      const appContainer = TestUtils.renderIntoDocument(
        <App draggableRefCb={(_ref) => {dragRef = _ref;}}/>
      );

      // (element, fromX, fromY, toX, toY)
      simulateMovementFromTo(dragRef.current, 0, 0, 100, 100);

      // ok, was a setstate warning thrown?
      // Assert unmounted
      assert.equal(dragRef.current, null);
    });

  });

  describe('DraggableCore callbacks', function () {
    it('should call back with node on drag', function(done) {
      function onDrag(event, data) {
        assert.equal(data.x, 100);
        assert.equal(data.y, 100);
        assert.equal(data.deltaX, 100);
        assert.equal(data.deltaY, 100);
        assert.equal(data.node, ReactDOM.findDOMNode(drag));
        done();
      }
      drag = TestUtils.renderIntoDocument(
        <DraggableCore onDrag={onDrag}>
          <div />
        </DraggableCore>
      );

      // (element, fromX, fromY, toX, toY)
      simulateMovementFromTo(drag, 0, 0, 100, 100);
    });

    it('should call back with correct position when parent element is 2x scaled', function(done) {
      function onDrag(event, data) {
        // visually it will look like 100, because parent is 2x scaled
        assert.equal(data.x, 50);
        assert.equal(data.y, 50);
        assert.equal(data.deltaX, 50);
        assert.equal(data.deltaY, 50);
        assert.equal(data.node, ReactDOM.findDOMNode(drag));
        done();
      }
      drag = TestUtils.renderIntoDocument(
        <DraggableCore onDrag={onDrag} scale={2}>
          <div />
        </DraggableCore>
      );

      // (element, fromX, fromY, toX, toY)
      simulateMovementFromTo(drag, 0, 0, 100, 100);
    });

    it('should call back with correct position when parent element is 0.5x scaled', function(done) {
      function onDrag(event, data) {
        // visually it will look like 100, because parent is  0.5x scaled
        assert.equal(data.x, 200);
        assert.equal(data.y, 200);
        assert.equal(data.deltaX, 200);
        assert.equal(data.deltaY, 200);
        assert.equal(data.node, ReactDOM.findDOMNode(drag));
        done();
      }
      drag = TestUtils.renderIntoDocument(
        <DraggableCore onDrag={onDrag} scale={0.5}>
          <div />
        </DraggableCore>
      );

      // (element, fromX, fromY, toX, toY)
      simulateMovementFromTo(drag, 0, 0, 100, 100);
    });

    it('should call back with snapped data output when grid prop is provided', function(done) {
      function onDrag(event, data) {
        assert.equal(data.x, 99);
        assert.equal(data.y, 96);
        assert.equal(data.deltaX, 99);
        assert.equal(data.deltaY, 96);
        assert.equal(data.node, ReactDOM.findDOMNode(drag));
      }
      function onStop(event, data) {
        assert.equal(data.x, 99);
        assert.equal(data.y, 96);
        // Single drag-and-stop so stop {x, y} is same as drag {x, y}.
        assert.equal(data.deltaX, 0);
        assert.equal(data.deltaY, 0);
        assert.equal(data.node, ReactDOM.findDOMNode(drag));
        done();
      }
      drag = TestUtils.renderIntoDocument(
        <DraggableCore onDrag={onDrag} onStop={onStop} grid={[9, 16]}>
          <div />
        </DraggableCore>
      );

      // (element, fromX, fromY, toX, toY)
      simulateMovementFromTo(drag, 0, 0, 100, 100);
    });
  });


  describe('validation', function () {
    it('should result with invariant when there isn\'t a child', function () {
      const renderer = new ShallowRenderer();

      assert.throws(() => renderer.render(<Draggable />));
    });

    it('should result with invariant if there\'s more than a single child', function () {
      const renderer = new ShallowRenderer();

      assert.throws(() => renderer.render(<Draggable><div/><div/></Draggable>));
    });
  });
});

function renderToHTML(component) {
  return renderToNode(component).outerHTML;
}

function renderToNode(component) {
  return ReactDOM.findDOMNode(TestUtils.renderIntoDocument(component));
}

// Simulate a movement; can't use TestUtils here because it uses react's event system only,
// but <DraggableCore> attaches event listeners directly to the document.
// Would love to new MouseEvent() here but it doesn't work with PhantomJS / old browsers.
// var e = new MouseEvent('mousemove', {clientX: 100, clientY: 100});
function mouseMove(x, y, node) {
  const doc = node ? node.ownerDocument : document;
  const evt = doc.createEvent('MouseEvents');
  evt.initMouseEvent('mousemove', true, true, window,
      0, 0, 0, x, y, false, false, false, false, 0, null);
  doc.dispatchEvent(evt);
  return evt;
}


function simulateMovementFromTo(drag, fromX, fromY, toX, toY) {
  const node = ReactDOM.findDOMNode(drag);

  TestUtils.Simulate.mouseDown(node, {clientX: fromX, clientY: fromY});
  mouseMove(toX, toY, node);
  TestUtils.Simulate.mouseUp(node);
}

function fragmentFromString(strHTML) {
  var temp = document.createElement('div');
  temp.innerHTML = strHTML;
  return temp.children[0];
}

function transplantNodeInto(node, into, selector) {
  node.parentNode.removeChild(node);
  selector(into).appendChild(node);
  document.body.appendChild(into);
}