test: add back-top test

components/back-top/__tests__/index.test.js

@@ -0,0 +1,27 @@
+import { mount } from '@vue/test-utils'
+import BackTop from '..'
+
+describe('BackTop', () => {
+  beforeAll(() => {
+    jest.useFakeTimers()
+  })
+
+  afterAll(() => {
+    jest.useRealTimers()
+  })
+
+  it('should scroll to top after click it', () => {
+    const wrapper = mount(BackTop, {
+      propsData: {
+        visibilityHeight: -1,
+      },
+    })
+    document.documentElement.scrollTop = 400
+    // trigger scroll manually
+    wrapper.vm.handleScroll()
+    jest.runAllTimers()
+    wrapper.find('.ant-back-top').trigger('click')
+    jest.runAllTimers()
+    expect(Math.abs(Math.round(document.documentElement.scrollTop))).toBe(0)
+  })
+})