[new feature] Collapse: add border prop (#2933)

packages/collapse/test/__snapshots__/index.spec.js.snap

@@ -1,5 +1,28 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`disable border 1`] = `
+<div class="van-collapse">
+  <div class="van-collapse-item">
+    <div class="van-cell van-cell--clickable van-collapse-item__title">
+      <div class="van-cell__title"><span>a</span></div><i class="van-icon van-icon-arrow van-cell__right-icon">
+        <!----></i>
+    </div>
+  </div>
+  <div class="van-collapse-item van-hairline--top">
+    <div class="van-cell van-cell--clickable van-collapse-item__title">
+      <div class="van-cell__title"><span>b</span></div><i class="van-icon van-icon-arrow van-cell__right-icon">
+        <!----></i>
+    </div>
+  </div>
+  <div class="van-collapse-item van-hairline--top">
+    <div class="van-cell van-cell--clickable van-collapse-item__title">
+      <div class="van-cell__title"><span>c</span></div><i class="van-icon van-icon-arrow van-cell__right-icon">
+        <!----></i>
+    </div>
+  </div>
+</div>
+`;
+
 exports[`render collapse-item slot 1`] = `
 <div class="van-collapse van-hairline--top-bottom">
   <div class="van-collapse-item">

packages/collapse/test/index.spec.js

@@ -4,7 +4,7 @@ import { later, mount } from '../../../test/utils';
 
 const component = {
   template: `
-  <collapse v-model="active" :accordion="accordion">
+  <collapse v-model="active" :accordion="accordion" :border="border">
     <collapse-item title="a" name="first">content</collapse-item>
     <collapse-item title="b">content</collapse-item>
     <collapse-item title="c">content</collapse-item>
@@ -15,7 +15,11 @@ const component = {
     CollapseItem
   },
   props: {
-    accordion: Boolean
+    accordion: Boolean,
+    border: {
+      type: Boolean,
+      default: true
+    }
   },
   data() {
     return {
@@ -89,3 +93,13 @@ it('render collapse-item slot', () => {
 
   expect(wrapper).toMatchSnapshot();
 });
+
+it('disable border', () => {
+  const wrapper = mount(component, {
+    propsData: {
+      border: false
+    }
+  });
+
+  expect(wrapper).toMatchSnapshot();
+});