add Arrow tests

src/__tests__/Tooltip/Arrow/Arrow.test.js

@@ -0,0 +1,24 @@
+import Arrow from '../../../Tooltip/Arrow/Arrow'
+import style from '../../../Tooltip/Arrow/style'
+
+describe('Arrow', () => {
+  const [arrowSize, buttonSize, backgroundColor, icons] = [
+    5, 10, '#C565A4', { length: 2 }
+  ]
+  const props = { arrowSize, buttonSize, backgroundColor, icons }
+
+  it('should render the tooltip arrow', () => {
+    const arrow = Arrow(props)
+
+    expect(arrow.nodeName).toEqual('DIV')
+  })
+
+  it('should render the arrow with the correct style', () => {
+    const arrow = Arrow(props)
+
+    const expected = document.createElement('div')
+    expected.style.cssText = style(props)
+
+    expect(arrow.style.cssText).toEqual(expected.style.cssText)
+  })
+})