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

[Rockergmail]

Fixes#2567

Changes you made in this pull request:

• props增加errorText
• data增加error
• load事件增加参数：handleError

[chenjiahan]

👍 很棒的功能

提一点小建议，目前 vant 会尽量避免在 i18n 文件中添加新的字段（除非是比较通用的），避免体积膨胀，所以能否把 error-text 的默认值去除，

[codecov-io]

Codecov Report

Merging #2568 into dev will decrease coverage by 0.08%.
The diff coverage is 33.33%.

@@ Coverage Diff @@## dev #2568 +/- ##
==========================================
- Coverage 87.21% 87.13% -0.09% 
==========================================
Files 104 104 Lines 1893 1896 +3 Branches 188 188 ==========================================
+ Hits 1651 1652 +1 - Misses 211 213 +2 
Partials 31 31

Impacted Files	Coverage Δ
packages/list/index.js	92.59% <33.33%> (-7.41%)	⬇️
packages/card/index.js	100% <0%> (ø)	⬆️
packages/dialog/Dialog.js	100% <0%> (ø)	⬆️
packages/image-preview/index.js	100% <0%> (ø)	⬆️
packages/image-preview/ImagePreview.js	94.04% <0%> (+0.07%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update e45780d...e2558d2. Read the comment docs.

[Rockergmail]

@chenjiahan 谢谢。我先去掉吧。稍等下

[Rockergmail]

@chenjiahan done.

[chenjiahan]

刚想了一下，控制 error 状态可以考虑使用传入 props 配合 sync 修饰符来做

<van-list:error.sync="error" />

exportdefault{data(){
error: false},methods: {onLoad(){ajax().catch(()=>{this.error=true;})}}}

这样的好处是不依赖传入回调函数，使用者可以更灵活地控制错误状态，你看下是否能完成你的需求~

[Rockergmail]

@chenjiahan 请教一下：

1. .sync的jest测试怎么写？

const wrapper = mount(List, {
propsData: {
errorText: 'Request failed. Click to reload...',
error: true
},
listeners: {
'update:error': ($event) => {
// 这个如何为error赋值？下面的写法是错的
this.error = $event;
}
}
});

2. 为什么mockOffsetParent能够模拟父元素位置的偏移？我看了代码，就是为父元素的dom添加了offsetParent这个响应式变量啊

[chenjiahan]

1. 可以用 wrapper.setProps({ error }) 来更新属性
2. offsetParent 是为了跳过代码里的 offsetParent !== null 这个判断

[Rockergmail]

@chenjiahan ci检测说packages/dialog/test/index.spec.js不通过，我没有改过对应的代码

FAIL packages/dialog/test/index.spec.js
● before close
expect(received).toBeFalsy()
Received: [[]]
43 | 44 | cancel.trigger('click');
> 45 | expect(wrapper.emitted('cancel')).toBeFalsy();
| ^
46 | 47 | wrapper.setProps({
48 | beforeClose: (action, done) => done()
at Object.toBeFalsy (packages/dialog/test/index.spec.js:45:37)

[chenjiahan]

Sorry 是我的失误，已经修复了

[chenjiahan]

Merge 了哈~ 会在下个版本发布

[Rockergmail]

@chenjiahan 这是我第一次PR，以后有机会多多指教哈

[chenjiahan]

哈哈，非常欢迎，期待你的下个 PR~