fix cascader test

test/unit/specs/cascader.spec.js

@@ -358,9 +358,9 @@ describe('Cascader', () => {
 
       const menu = vm.$refs.cascader.menu;
       const menuElm = menu.$el;
-      const item1 = menuElm.children[0].querySelector('.el-cascader-menu__item');
-      const item2 = menuElm.children[1].querySelector('.el-cascader-menu__item');
-      const item3 = menuElm.children[2].querySelector('.el-cascader-menu__item');
+      const item1 = menuElm.children[1].querySelector('.el-cascader-menu__item');
+      const item2 = menuElm.children[2].querySelector('.el-cascader-menu__item');
+      const item3 = menuElm.children[3].querySelector('.el-cascader-menu__item');
 
       expect(menuElm.children.length).to.be.equal(4);
       expect(item1.classList.contains('is-active')).to.be.true;
@@ -600,7 +600,7 @@ describe('Cascader', () => {
         const item1 = menuElm.querySelector('.el-cascader-menu__item');
 
         expect(menuElm.children.length).to.be.equal(2);
-        expect(menuElm.children[0].children.length).to.be.equal(3);
+        expect(menuElm.children[1].children.length).to.be.equal(3);
 
         item1.click();