Add spec for dragging carg

__mocks__/react-beautiful-dnd.js

@@ -1,9 +1,5 @@
 import React from 'react'
 
-const callbacks = {
-  onDragEnd: jest.fn()
-}
-
 function DragDropContext (props) {
   callbacks.onDragEnd = props.onDragEnd
 
@@ -23,8 +19,15 @@ const draggableProvide = {
   draggableProps: {},
   dragHandleProps: {}
 }
+const draggableSnapshot = {
+  isDragging: false
+}
 function Draggable (props) {
-  return <>{props.children(draggableProvide)}</>
+  return <>{props.children(draggableProvide, draggableSnapshot)}</>
 }
 
+const callbacks = {
+  onDragEnd: jest.fn(),
+  isDragging: isDragging => { draggableSnapshot.isDragging = isDragging }
+}
 export { DragDropContext, Droppable, Draggable, callbacks }

src/components/Board/components/Lane/components/Card/index.spec.js

@@ -1,30 +1,43 @@
 import React from 'react'
 import { render } from 'react-testing-library'
 import Card from './'
+import { callbacks } from 'react-beautiful-dnd'
 
 describe('<Card />', () => {
   let subject
 
-  beforeEach(() => {
+  function mount () {
     const card = {
       id: 1,
       title: 'Card title',
       description: 'Card content'
     }
 
     subject = render(<Card>{card}</Card>)
-  })
+    return subject
+  }
   afterEach(() => { subject = undefined })
 
   it('renders a card', () => {
-    expect(subject.container).toBeInTheDocument()
+    expect(mount().container).toBeInTheDocument()
   })
 
   it("renders the card's title", () => {
-    expect(subject.queryByText(/^Card title$/)).toBeInTheDocument()
+    expect(mount().queryByText(/^Card title$/)).toBeInTheDocument()
   })
 
   it("renders the card's description", () => {
-    expect(subject.queryByText(/^Card content$/)).toBeInTheDocument()
+    expect(mount().queryByText(/^Card content$/)).toBeInTheDocument()
+  })
+
+  describe('when the card is being dragging', () => {
+    beforeEach(() => {
+      callbacks.isDragging(true)
+      mount()
+    })
+
+    it('shows the card with a box shadow', () => {
+      expect(subject.queryByText(/^Card title$/).parentNode).toHaveStyle('box-shadow: 2px 2px grey')
+    })
   })
 })