[improvement] update eslint rules (#2089)

packages/image-preview/ImagePreview.vue

@@ -6,14 +6,22 @@
     @touchend="onWrapperTouchEnd"
     @touchcancel="onWrapperTouchEnd"
   >
-    <div v-if="showIndex" :class="b('index')">{{ active + 1 }}/{{ count }}</div>
+    <div
+      v-if="showIndex"
+      :class="b('index')"
+    >
+      {{ active + 1 }}/{{ count }}
+    </div>
     <swipe
       ref="swipe"
       :initial-swipe="startPosition"
       :show-indicators="showIndicators"
       @change="onChange"
     >
-      <swipe-item v-for="(item, index) in images" :key="index">
+      <swipe-item
+        v-for="(item, index) in images"
+        :key="index"
+      >
         <img
           :class="b('image')"
           :src="item"

packages/image-preview/test/__snapshots__/index.spec.js.snap

@@ -2,7 +2,9 @@
 
 exports[`render image 1`] = `
 <div class="van-image-preview">
-  <div class="van-image-preview__index">1/3</div>
+  <div class="van-image-preview__index">
+    1/3
+  </div>
   <div class="van-swipe">
     <div class="van-swipe__track" style="width: 0px;">
       <div class="van-swipe-item" style="width: 0px; height: 100%;">
@@ -22,7 +24,9 @@ exports[`render image 1`] = `
 
 exports[`zoom 1`] = `
 <div class="van-image-preview">
-  <div class="van-image-preview__index">1/3</div>
+  <div class="van-image-preview__index">
+    1/3
+  </div>
   <div class="van-swipe">
     <div class="van-swipe__track" style="width: 300px;">
       <div class="van-swipe-item" style="width: 100px; height: 100%;">