[web] Add tests for js/components/helpers/AutoScroll.js

web/src/js/__tests__/components/helpers/AutoScrollSpec.js

@@ -0,0 +1,41 @@
+import React from "react"
+import ReactDOM from "react-dom"
+import AutoScroll from '../../../components/helpers/AutoScroll'
+import { calcVScroll } from '../../../components/helpers/VirtualScroll'
+import TestUtils from 'react-dom/test-utils'
+
+describe('Autoscroll', () => {
+    let mockFn = jest.fn()
+    class tComponent extends React.Component {
+        constructor(props, context){
+            super(props, context)
+            this.state = { vScroll: calcVScroll() }
+        }
+
+       componentWillUpdate() {
+           mockFn("foo")
+       }
+
+       componentDidUpdate() {
+           mockFn("bar")
+       }
+
+       render() {
+           return (<p>foo</p>)
+       }
+    }
+
+    it('should update component', () => {
+        let Foo = AutoScroll(tComponent),
+            autoScroll = TestUtils.renderIntoDocument(<Foo></Foo>),
+            viewport = ReactDOM.findDOMNode(autoScroll)
+        viewport.scrollTop = 10
+        Object.defineProperty(viewport, "scrollHeight", { value: 10, writable: true })
+        autoScroll.componentWillUpdate()
+        expect(mockFn).toBeCalledWith("foo")
+
+        Object.defineProperty(viewport, "scrollHeight", { value: 0, writable: true })
+        autoScroll.componentDidUpdate()
+        expect(mockFn).toBeCalledWith("bar")
+    })
+})