Calendar: Should not switch to earliest date if same value is set programmatically (T1279950)

packages/devextreme/js/__internal/core/utils/m_date.ts

@@ -459,6 +459,26 @@ const sameCentury = function (date1, date2) {
   return date1 && date2 && startCenturyDate1 === startCenturyDate2;
 };
 
+const sameDatesArrays = (arr1: Date[], arr2: Date[]): boolean => {
+  if (!Array.isArray(arr1) || !Array.isArray(arr2) || arr1.length !== arr2.length) {
+    return false;
+  }
+
+  return arr1.every((date1, index) => {
+    const date2 = arr2[index];
+
+    if ([date1, date2].some((date) => date !== null && !(date instanceof Date))) {
+      return false;
+    }
+
+    if (date1 instanceof Date && date2 instanceof Date) {
+      return sameDate(date1, date2);
+    }
+
+    return date1 === date2;
+  });
+};
+
 function getFirstDecadeInCentury(date) {
   return date && date.getFullYear() - date.getFullYear() % 100;
 }
@@ -768,6 +788,7 @@ const dateUtils = {
   sameDecade,
   sameCentury,
   sameView,
+  sameDatesArrays,
   getDifferenceInMonth,
   getDifferenceInMonthForCells,
   getFirstYearInDecade,

packages/devextreme/js/__internal/ui/calendar/m_calendar.multiple.selection.strategy.ts

@@ -39,7 +39,7 @@ class CalendarMultiSelectionStrategy extends CalendarSelectionStrategy {
   }
 
   getDefaultCurrentDate() {
-    const dates = this.dateOption('value').filter((value) => value);
+    const dates = this.dateOption('value').filter(Boolean);
     return this._getLowestDateInArray(dates);
   }
 

packages/devextreme/js/__internal/ui/calendar/m_calendar.ts

@@ -1608,11 +1608,17 @@ class Calendar<
         this._correctZoomLevel();
         this._updateButtonsVisibility();
         break;
-      case 'value':
-        this._selectionStrategy.processValueChanged(value, previousValue);
+      case 'value': {
+        const isSameValue = dateUtils.sameDatesArrays(value, previousValue);
+
+        if (!isSameValue) {
+          this._selectionStrategy.processValueChanged(value, previousValue);
+        }
+
         this._setSubmitValue(value);
         super._optionChanged(args);
         break;
+      }
       case 'viewsCount':
         this._refreshViews();
         this._renderNavigator();

packages/devextreme/testing/tests/DevExpress.core/utils.date.tests.js

@@ -1773,3 +1773,50 @@ QUnit.module('intervalsOverlap', () => {
         }), 'Intervals overlaps');
     });
 });
+
+QUnit.module('sameDatesArrays', () => {
+    QUnit.test('Empty arrays', function(assert) {
+        assert.ok(dateUtils.sameDatesArrays([], []), 'empty arrays are equal');
+    });
+
+    QUnit.test('Arrays of different length', function(assert) {
+        assert.notOk(dateUtils.sameDatesArrays([], [new Date(2025, 1, 1)]), 'arrays of different length are not equal');
+    });
+
+    QUnit.test('Non-arrays', function(assert) {
+        assert.notOk(dateUtils.sameDatesArrays(null, null), 'both null arguments are not array');
+        assert.notOk(dateUtils.sameDatesArrays(null, new Date(2025, 1, 1)), 'first null is not an array');
+        assert.notOk(dateUtils.sameDatesArrays(new Date(2025, 1, 1), null), 'second null is not an array');
+        assert.notOk(dateUtils.sameDatesArrays('string', 'string'), 'strings are not arrays');
+    });
+
+    QUnit.test('Same arrays with valid dates', function(assert) {
+        const arr1 = [new Date(2025, 1, 1), new Date(2025, 2, 1)];
+        const arr2 = [new Date(2025, 1, 1), new Date(2025, 2, 1)];
+        assert.ok(dateUtils.sameDatesArrays(arr1, arr2), 'arrays with same dates are equal');
+    });
+
+    QUnit.test('Same arrays with null dates', function(assert) {
+        const arr1 = [new Date(2025, 1, 1), null];
+        const arr2 = [new Date(2025, 1, 1), null];
+        assert.ok(dateUtils.sameDatesArrays(arr1, arr2), 'arrays with same empty dates are equal');
+    });
+
+    QUnit.test('Different arrays with valid dates', function(assert) {
+        const arr1 = [new Date(2025, 1, 1), new Date(2025, 2, 1)];
+        const arr2 = [new Date(2025, 1, 1), new Date(2025, 3, 1)];
+        assert.notOk(dateUtils.sameDatesArrays(arr1, arr2), 'arrays with different dates are not equal');
+    });
+
+    QUnit.test('Different arrays with null dates', function(assert) {
+        const arr1 = [null, new Date(2025, 2, 1)];
+        const arr2 = [new Date(2025, 2, 1), null];
+        assert.notOk(dateUtils.sameDatesArrays(arr1, arr2), 'arrays with different empty dates are not equal');
+    });
+
+    QUnit.test('Arrays with non-null and non-Date values', function(assert) {
+        const arr1 = ['string'];
+        const arr2 = ['string'];
+        assert.notOk(dateUtils.sameDatesArrays(arr1, arr2), 'arrays with strings are not equal dates');
+    });
+});

packages/devextreme/testing/tests/DevExpress.ui.widgets.editors/calendar.tests.js

@@ -873,6 +873,46 @@ QUnit.module('Views integration', {
 
         assert.strictEqual($contouredCell.length, 0, 'there is no contoured date cell');
     });
+
+    QUnit.test('should not navigate view after new date UI select, even in React controlled mode (T1279950)', function(assert) {
+        this.calendar.option({
+            selectionMode: 'multiple',
+            value: [new Date(2025, 1, 10), new Date(2025, 2, 10)],
+        });
+
+        const calendar = this.calendar;
+        const $nextMonthButton = this.$element.find(toSelector(CALENDAR_NAVIGATOR_NEXT_MONTH_CLASS));
+
+        assert.ok(
+            dateUtils.sameMonth(calendar.option('currentDate'), new Date(2025, 1, 10)),
+            'initially navigated to the earliest date'
+        );
+
+        $($nextMonthButton).trigger('dxclick');
+
+        assert.ok(
+            dateUtils.sameMonth(calendar.option('currentDate'), new Date(2025, 2, 10)),
+            'navigated to the next month'
+        );
+
+        calendar.option('value', [new Date(2025, 1, 10), new Date(2025, 2, 10)]);
+
+        assert.ok(
+            dateUtils.sameMonth(calendar.option('currentDate'), new Date(2025, 2, 10)),
+            'did not navigate back to the earliest date'
+        );
+
+        const $cell = this.$element.find('*[data-value="2025/03/10"]');
+
+        $cell.trigger('dxclick');
+
+        assert.strictEqual(this.calendar.option('value').length, 1, 'deselected correctly');
+
+        assert.ok(
+            dateUtils.sameMonth(calendar.option('currentDate'), new Date(2025, 2, 10)),
+            'did not navigate back to the earliest date after deseleting'
+        );
+    });
 });