DatePicker: add reverse selection test (#10035)

test/unit/specs/date-picker.spec.js

@@ -1328,6 +1328,50 @@ describe('DatePicker', () => {
       }, DELAY);
     });
 
+    it('works: reverse selection', done => {
+      vm = createVue({
+        template: '<el-date-picker type="daterange" v-model="value" ref="compo" />',
+        data() {
+          return {
+            value: ''
+          };
+        }
+      }, true);
+
+      const rangePicker = vm.$refs.compo;
+      const inputs = rangePicker.$el.querySelectorAll('input');
+      inputs[0].focus();
+
+      setTimeout(_ => {
+        const panels = rangePicker.picker.$el.querySelectorAll('.el-date-range-picker__content');
+        expect(Array.prototype.slice.call(panels)).to.length(2);
+        panels[1].querySelector('td.available').click();
+        setTimeout(_ => {
+          panels[0].querySelector('td.available').click();
+          setTimeout(_ => {
+            inputs[0].focus();
+            setTimeout(_ => {
+              // correct highlight
+              const startDate = rangePicker.picker.$el.querySelectorAll('.start-date');
+              const endDate = rangePicker.picker.$el.querySelectorAll('.end-date');
+              const inRangeDate = rangePicker.picker.$el.querySelectorAll('.in-range');
+              expect(startDate.length).to.equal(1);
+              expect(endDate.length).to.equal(1);
+              expect(inRangeDate.length).to.above(0);
+              // value is array
+              expect(vm.value).to.be.an.instanceof(Array);
+              // input text is something like date string
+              expect(inputs[0].value.length).to.equal(10);
+              expect(inputs[1].value.length).to.equal(10);
+              // result array is properly ordered
+              expect(vm.value[0].getTime() < vm.value[1].getTime()).to.be.true;
+              done();
+            }, DELAY);
+          }, DELAY);
+        }, DELAY);
+      }, DELAY);
+    });
+
     it('type:daterange unlink:true', done => {
       vm = createVue({
         template: '<el-date-picker type="daterange" unlink-panels v-model="value" ref="compo" />',