feat(Calendar): add multiple type (#5705)

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

@@ -7,6 +7,10 @@ exports[`renders demo correctly 1`] = `
       <div class="van-cell__title"><span>选择单个日期</span></div><i class="van-icon van-icon-arrow van-cell__right-icon">
         <!----></i>
     </div>
+    <div role="button" tabindex="0" class="van-cell van-cell--clickable">
+      <div class="van-cell__title"><span>选择多个日期</span></div><i class="van-icon van-icon-arrow van-cell__right-icon">
+        <!----></i>
+    </div>
     <div role="button" tabindex="0" class="van-cell van-cell--clickable">
       <div class="van-cell__title"><span>选择日期区间</span></div><i class="van-icon van-icon-arrow van-cell__right-icon">
         <!----></i>

src/calendar/test/index.spec.js

@@ -18,6 +18,10 @@ function formatRange([start, end]) {
   return `${formatDate(start)}-${formatDate(end)}`;
 }
 
+function formatMultiple(dates) {
+  return dates.map(formatDate).join(',');
+}
+
 test('select event when type is single', async () => {
   const wrapper = mount(Calendar, {
     propsData: {
@@ -63,6 +67,36 @@ test('select event when type is range', async () => {
   expect(formatRange(emittedSelect[3][0])).toEqual('2010/1/13-');
 });
 
+test('select event when type is multiple', async () => {
+  const wrapper = mount(Calendar, {
+    propsData: {
+      type: 'multiple',
+      minDate,
+      maxDate,
+      poppable: false,
+    },
+  });
+
+  await later();
+
+  const days = wrapper.findAll('.van-calendar__day');
+  days.at(15).trigger('click');
+  days.at(16).trigger('click');
+
+  await later();
+  days.at(15).trigger('click');
+  days.at(12).trigger('click');
+
+  const emittedSelect = wrapper.emitted('select');
+  expect(formatMultiple(emittedSelect[0][0])).toEqual('2010/1/10,2010/1/16');
+  expect(formatMultiple(emittedSelect[1][0])).toEqual(
+    '2010/1/10,2010/1/16,2010/1/17'
+  );
+  expect(formatMultiple(emittedSelect[2][0])).toEqual(
+    '2010/1/10,2010/1/17,2010/1/13'
+  );
+});
+
 test('should not trigger select event when click disabled day', async () => {
   const wrapper = mount(Calendar, {
     propsData: {