fix(DateTimePicker): fix incorrecrt inital value (#8193)

src/datetime-picker/test/date-picker.legacy.js

@@ -208,7 +208,7 @@ test('use min-date with filter', async () => {
   });
 
   await later();
-
+  
   wrapper.find('.van-picker__confirm').trigger('click');
   expect(wrapper.emitted('confirm')[0][0]).toEqual(new Date(2030, 0, 0, 0, 30));
 });

src/datetime-picker/test/index.spec.js

@@ -0,0 +1,59 @@
+import {later, mount, triggerDrag} from "../../../test"
+import DatePicker from "../DatePicker"
+
+test('month-day type', async () => {
+  const date = new Date(2020, 10, 1, 0, 0);
+
+  const wrapper = mount(DatePicker, {
+    props: {
+      type: 'month-day',
+      modelValue: date,
+      minDate: new Date(2020, 0, 1),
+      maxDate: new Date(2025, 10, 1),
+    },
+  });
+
+  await later();
+  wrapper.find('.van-picker__confirm').trigger('click');
+  expect(wrapper.emitted('confirm')[0][0].getMonth()).toEqual(10);
+  expect(wrapper.emitted('confirm')[0][0].getDate()).toEqual(1);
+
+  await later();
+  triggerDrag(wrapper.find('.van-picker-column'), 0, -300);
+  wrapper.find('.van-picker__confirm').trigger('click');
+  expect(wrapper.emitted('confirm')[1][0].getMonth()).toEqual(11);
+  expect(wrapper.emitted('confirm')[1][0].getDate()).toEqual(1);
+
+  await later();
+  triggerDrag(wrapper.findAll('.van-picker-column')[1], 0, -300);
+  wrapper.find('.van-picker__confirm').trigger('click');
+  expect(wrapper.emitted('confirm')[2][0].getMonth()).toEqual(11);
+  expect(wrapper.emitted('confirm')[2][0].getDate()).toEqual(31);
+});
+
+test('v-model', async () => {
+  const minDate = new Date(2030, 0, 0, 0, 3);
+
+  const wrapper = mount(DatePicker, {
+    props: {
+      minDate,
+    }
+  })
+  
+  await later();
+  wrapper.find('.van-picker__confirm').trigger('click');
+  expect(wrapper.emitted('confirm')[0][0]).toEqual(minDate);
+});
+
+test('value has an inital value', async () => {
+  const defaultValue = new Date(2020, 0, 0, 0, 0);
+  const wrapper = mount(DatePicker, {
+    propsData: {
+      modelValue: defaultValue,
+    },
+  });
+
+  await later();
+  wrapper.find('.van-picker__confirm').trigger('click');
+  expect(wrapper.emitted('confirm')[0][0]).toEqual(defaultValue);
+});