PivotGrid: T1317109 — fix memory leak after PivotGridDataSource is reassigned

packages/devextreme/js/__internal/grids/pivot_grid/field_chooser/m_field_chooser.ts

@@ -143,7 +143,7 @@ export class FieldChooser extends FieldChooserBase {
 
   _dispose() {
     this._disposeDataSource();
-    super._dispose.apply(this, arguments);
+    super._dispose();
   }
 
   _init() {

packages/devextreme/js/__internal/grids/pivot_grid/m_widget.ts

@@ -135,6 +135,8 @@ class PivotGrid extends Widget {
 
   _fieldChooser: any;
 
+  _fieldChooserBase: any;
+
   _columnsArea: any;
 
   _rowsArea: any;
@@ -408,6 +410,9 @@ class PivotGrid extends Widget {
       case 'allowSortingBySummary':
       case 'scrolling':
       case 'stateStoring':
+        if (that._fieldChooserBase) {
+          that._fieldChooserBase._dispose();
+        }
         that._initDataController();
         that.getFieldChooserPopup().hide();
         that._renderFieldChooser();
@@ -1174,7 +1179,7 @@ class PivotGrid extends Widget {
 
     that.$element().addClass(OVERFLOW_HIDDEN_CLASS);
 
-    that._createComponent(that.$element(), FieldChooserBase, {
+    that._fieldChooserBase = that._createComponent(that.$element(), FieldChooserBase, {
       dataSource: that.getDataSource(),
       encodeHtml: that.option('encodeHtml'),
       allowFieldDragging: that.option('fieldPanel.allowFieldDragging'),
@@ -1266,10 +1271,16 @@ class PivotGrid extends Widget {
   _dispose() {
     const that = this;
     clearTimeout(that._hideLoadingTimeoutID);
-    super._dispose();
+
+    if (that._fieldChooserBase) {
+      that._fieldChooserBase._dispose();
+    }
+
     if (that._dataController) {
       that._dataController.dispose();
     }
+
+    super._dispose();
   }
 
   _tableElement() {

packages/devextreme/testing/tests/DevExpress.ui.widgets.pivotGrid/pivotGrid.tests.js

@@ -1044,6 +1044,24 @@ QUnit.module('dxPivotGrid', {
 
     });
 
+    QUnit.test('T1317109: fieldChooser disposes on dataSource change', function(assert) {
+        const pivotGrid = createPivotGrid({
+            dataSource: {
+                rows: [],
+                columns: [],
+                values: []
+            }
+        });
+
+        const disposeSpy = sinon.spy(pivotGrid._fieldChooserBase, '_dispose');
+
+        pivotGrid.option('dataSource', this.testOptions.dataSource);
+
+        this.clock.tick(500);
+
+        assert.ok(disposeSpy.calledOnce, '_dispose was called once on dataSource change');
+    });
+
     QUnit.test('not show field chooser popup on description area click when fieldChooser disabled', function(assert) {
         createPivotGrid({
             fieldChooser: {