fix some potential test err

test/unit/specs/alert.spec.js

@@ -29,7 +29,7 @@ describe('Alert', () => {
     expect(vm.$el.querySelector('.el-alert__description')).to.exist;
   });
 
-  it('close', done => {
+  it('close', () => {
     const vm = createVue({
       template: `
         <div>
@@ -40,9 +40,6 @@ describe('Alert', () => {
       `
     }, true);
     vm.$el.querySelector('.el-alert__closebtn').click();
-    setTimeout(() => {
-      expect(vm.$children[0].$el.style.display).to.equal('none');
-      done();
-    }, 300);
+    expect(vm.$children[0].visible).to.false;
   });
 });

test/unit/specs/slider.spec.js

@@ -36,7 +36,7 @@ describe('Slider', () => {
     }, 100);
   });
 
-  it('show tooltip', () => {
+  it('show tooltip', done => {
     const vm = createVue({
       template: `
         <div>
@@ -57,9 +57,8 @@ describe('Slider', () => {
     vm.$nextTick(() => {
       expect(popup.style.display).to.not.equal('none');
       slider.onDragEnd();
-      setTimeout(() => {
-        expect(popup.style.display).to.equal('none');
-      }, 350);
+      expect(slider.showTip).to.false;
+      done();
     });
   });
 

test/unit/specs/switch.spec.js

@@ -49,7 +49,7 @@ describe('Switch', () => {
     Vue.nextTick(() => {
       expect(vm.value).to.equal(false);
       expect(getComputedStyle(core).backgroundColor).to.equal('rgb(192, 204, 218)');
-      expect(button.style.transform).to.equal('translate3d(2px, 2px, 0)');
+      expect(/2px, 2px/.test(button.style.transform)).to.true;
       core.click();
       expect(vm.value).to.equal(true);
       done();