types: test cases typing

src/button/test/index.spec.ts

@@ -1,4 +1,4 @@
-import { mount } from '@vue/test-utils';
+import { mount } from '../../../test';
 import Button from '..';
 
 test('should emit click event', () => {
@@ -37,7 +37,7 @@ test('should hide border when color is gradient', () => {
     },
   });
 
-  expect(wrapper.element.style.border).toEqual('0px');
+  expect(wrapper.style.border).toEqual('0px');
 });
 
 test('should change icon class prefix when using icon-prefix prop', () => {
@@ -72,7 +72,7 @@ test('should render loading of a specific size when using loading-size prop', ()
     },
   });
 
-  const loading = wrapper.find('.van-loading__spinner').element;
+  const loading = wrapper.find('.van-loading__spinner');
   expect(loading.style.width).toEqual('10px');
   expect(loading.style.height).toEqual('10px');
 });