Calendar: Should switch to the last date view in multiple & controlled mode (T1279950)

Author: Ruslan Farkhutdinov

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

@@ -39,8 +39,10 @@ class CalendarMultiSelectionStrategy extends CalendarSelectionStrategy {
   }
 
   getDefaultCurrentDate() {
-    const dates = this.dateOption('value').filter((value) => value);
-    return this._getLowestDateInArray(dates);
+    const dates = this.dateOption('value').filter(Boolean);
+    if (dates.length) {
+      return dates[dates.length - 1];
+    }
   }
 
   restoreValue() {

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

@@ -1383,6 +1383,27 @@ QUnit.module('Preserve time component on value change', {
 
         assert.deepEqual(calendar.option('value'), new Date(2015, 8, 2, 12, 57));
     });
+
+    QUnit.test('should switch to the last date after setting option programmatically (T1279950)', function(assert) {
+        this.calendar.option({
+            selectionMode: 'multiple',
+            value: [new Date(2025, 1, 10), new Date(2025, 2, 10)],
+        });
+
+        const calendar = this.calendar;
+
+        assert.ok(
+            dateUtils.sameMonth(calendar.option('currentDate'), new Date(2025, 2, 10)),
+            'initially navigated to the last date'
+        );
+
+        calendar.option('value', [new Date(2025, 2, 10), new Date(2025, 4, 10), new Date(2025, 3, 10)]);
+
+        assert.ok(
+            dateUtils.sameMonth(calendar.option('currentDate'), new Date(2025, 3, 10)),
+            'switched to the last entered date'
+        );
+    });
 });
 
 
@@ -2015,15 +2036,15 @@ QUnit.module('Options', {
 
             [
                 {
-                    value: [new Date('01/05/2023'), new Date('02/01/2023')],
+                    value: [new Date('02/01/2023'), new Date('01/05/2023')],
                     type: 'dates'
                 },
                 {
-                    value: ['01/05/2023', '02/01/2023'],
+                    value: ['02/01/2023', '01/05/2023'],
                     type: 'strings'
                 },
                 {
-                    value: [1672916400000, 1675249200000],
+                    value: [1675249200000, 1672916400000],
                     type: 'numbers'
                 }
             ].forEach(({ value, type }) => {
@@ -2040,14 +2061,23 @@ QUnit.module('Options', {
             });
 
             QUnit.module('CurrentDate', {}, () => {
-                QUnit.test(`Should be equal to the lowest defined date in value on init (selectionMode=${selectionMode}`, function(assert) {
+                const isMultipleMode = selectionMode === 'multiple';
+                const currentDateRule = isMultipleMode ? 'latest entered' : 'lowest defined';
+
+                QUnit.test(`Should be equal to the ${currentDateRule} date in value on init (selectionMode=${selectionMode}`, function(assert) {
+                    const initialValue = [null, new Date('01/15/2023'), new Date('02/01/2023')];
+
                     this.reinit({
-                        value: [null, new Date('01/15/2023'), new Date('02/01/2023')],
+                        value: initialValue,
                         selectionMode
                     });
                     const { currentDate, value } = this.calendar.option();
 
-                    assert.deepEqual(currentDate, new Date(Math.min(...value.filter(value => value))));
+                    if(isMultipleMode) {
+                        assert.deepEqual(currentDate, initialValue[initialValue.length - 1]);
+                    } else {
+                        assert.deepEqual(currentDate, new Date(Math.min(...value.filter(value => value))));
+                    }
                 });
 
                 QUnit.test(`Should be equal to the lowest date in value on runtime value change (selectionMode=${selectionMode}`, function(assert) {
@@ -2106,7 +2136,7 @@ QUnit.module('Options', {
             });
 
             QUnit.test('It should be possible to deselect already selected value by click', function(assert) {
-                const $cell = $(getCurrentViewInstance(this.calendar).$element().find('*[data-value="2023/01/15"]'));
+                const $cell = $(getCurrentViewInstance(this.calendar).$element().find('*[data-value="2023/02/01"]'));
 
                 $cell.trigger('dxclick');