feat(Popup): add close-icon prop (#4366)

src/popup/test/__snapshots__/demo.spec.js.snap

@@ -14,6 +14,7 @@ exports[`renders demo correctly 1`] = `
     <!---->
   </div>
   <div><button class="van-button van-button--primary van-button--normal"><span class="van-button__text">关闭图标</span></button>
+    <!----> <button class="van-button van-button--primary van-button--normal"><span class="van-button__text">自定义图标</span></button>
     <!---->
   </div>
   <div><button class="van-button van-button--primary van-button--normal"><span class="van-button__text">圆角弹窗</span></button>

src/popup/test/__snapshots__/index.spec.js.snap

@@ -1,5 +1,10 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`close-icon prop 1`] = `
+<div class="van-popup van-popup--center" name="van-fade"><i class="van-icon van-icon-success van-popup__close-icon">
+    <!----></i></div>
+`;
+
 exports[`duration prop 1`] = `<div class="van-popup van-popup--center" style="transition-duration: 0.5s;" name="van-fade"></div>`;
 
 exports[`reset z-index 1`] = `<div class="van-popup van-popup--center" name="van-fade"></div>`;

src/popup/test/index.spec.js

@@ -239,3 +239,15 @@ test('closeable prop', () => {
   wrapper.find('.van-popup__close-icon').trigger('click');
   expect(wrapper.emitted('input')[0][0]).toEqual(false);
 });
+
+test('close-icon prop', () => {
+  const wrapper = mount(Popup, {
+    propsData: {
+      value: true,
+      closeable: true,
+      closeIcon: 'success'
+    }
+  });
+
+  expect(wrapper).toMatchSnapshot();
+});