[new feature] List 考虑错误情况，增加 error-text 属性 #2567 (#2568)

packages/list/test/__snapshots__/demo.spec.js.snap

@@ -3,7 +3,15 @@
 exports[`renders demo correctly 1`] = `
 <div>
   <div>
-    <p class="page-desc">当即将滚动到元素底部时，会自动加载更多</p>
+    <div class="page-desc">
+      <p class="page-desc--text">当即将滚动到元素底部时，会自动加载更多</p>
+      <div class="page-desc--option van-checkbox">
+        <div class="van-checkbox__icon van-checkbox__icon--round"><i class="van-icon van-icon-success" style="color:undefined;font-size:undefined;">
+            <!----></i></div><span class="van-checkbox__label">
+        模拟加载失败
+      </span>
+      </div>
+    </div>
     <div class="van-pull-refresh">
       <div class="van-pull-refresh__track" style="transition:0ms;transform:translate3d(0,0px, 0);">
         <div class="van-pull-refresh__head">

packages/list/test/index.spec.js

@@ -29,6 +29,35 @@ test('load event', async () => {
   wrapper.destroy();
 });
 
+test('error loaded, click error-text and reload', async () => {
+  const wrapper = mount(List, {
+    propsData: {
+      errorText: 'Request failed. Click to reload...',
+      error: true
+    }
+  });
+
+  mockOffsetParent(wrapper.vm.$el);
+
+  await later();
+
+  expect(wrapper.emitted('load')).toBeFalsy();
+  expect(wrapper.emitted('input')).toBeFalsy();
+
+  // 模拟点击error-text的行为
+  wrapper.setProps({
+    error: false
+  });
+  wrapper.vm.$emit('input', true);
+  wrapper.vm.$emit('load');
+
+  expect(wrapper.vm.$props.error).toBeFalsy();
+  expect(wrapper.emitted('load')).toBeTruthy();
+  expect(wrapper.emitted('input')).toBeTruthy();
+
+  wrapper.destroy();
+});
+
 test('finished', async () => {
   const wrapper = mount(List, {
     propsData: {