diff --git a/packages/devextreme-angular/src/ui/card-view/index.ts b/packages/devextreme-angular/src/ui/card-view/index.ts
index bedbfc74436f..18850d31fbad 100644
--- a/packages/devextreme-angular/src/ui/card-view/index.ts
+++ b/packages/devextreme-angular/src/ui/card-view/index.ts
@@ -319,10 +319,10 @@ export class DxCardViewComponent<TCardData = any, TKey = any> extends DxComponen
 
     
     @Input()
-    get dataSource(): Array<any> | DataSource | DataSourceOptions | Store | string {
+    get dataSource(): Array<any> | DataSource | DataSourceOptions | Store | string | undefined {
         return this._getOption('dataSource');
     }
-    set dataSource(value: Array<any> | DataSource | DataSourceOptions | Store | string) {
+    set dataSource(value: Array<any> | DataSource | DataSourceOptions | Store | string | undefined) {
         this._setOption('dataSource', value);
     }
 
@@ -479,10 +479,10 @@ export class DxCardViewComponent<TCardData = any, TKey = any> extends DxComponen
 
     
     @Input()
-    get keyExpr(): Array<string> | string {
+    get keyExpr(): Array<string> | string | undefined {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: Array<string> | string) {
+    set keyExpr(value: Array<string> | string | undefined) {
         this._setOption('keyExpr', value);
     }
 
@@ -992,7 +992,7 @@ export class DxCardViewComponent<TCardData = any, TKey = any> extends DxComponen
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() dataSourceChange: EventEmitter<Array<any> | DataSource | DataSourceOptions | Store | string>;
+    @Output() dataSourceChange: EventEmitter<Array<any> | DataSource | DataSourceOptions | Store | string | undefined>;
 
     /**
     
@@ -1104,7 +1104,7 @@ export class DxCardViewComponent<TCardData = any, TKey = any> extends DxComponen
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() keyExprChange: EventEmitter<Array<string> | string>;
+    @Output() keyExprChange: EventEmitter<Array<string> | string | undefined>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/card-view/nested/filter-builder.ts b/packages/devextreme-angular/src/ui/card-view/nested/filter-builder.ts
index 8ae3ebf03689..f3600e3d6fdf 100644
--- a/packages/devextreme-angular/src/ui/card-view/nested/filter-builder.ts
+++ b/packages/devextreme-angular/src/ui/card-view/nested/filter-builder.ts
@@ -187,18 +187,18 @@ export class DxoCardViewFilterBuilderComponent extends NestedOption implements O
     }
 
     @Input()
-    get onEditorPrepared(): ((e: EditorPreparedEvent) => void) {
+    get onEditorPrepared(): ((e: EditorPreparedEvent) => void) | undefined {
         return this._getOption('onEditorPrepared');
     }
-    set onEditorPrepared(value: ((e: EditorPreparedEvent) => void)) {
+    set onEditorPrepared(value: ((e: EditorPreparedEvent) => void) | undefined) {
         this._setOption('onEditorPrepared', value);
     }
 
     @Input()
-    get onEditorPreparing(): ((e: EditorPreparingEvent) => void) {
+    get onEditorPreparing(): ((e: EditorPreparingEvent) => void) | undefined {
         return this._getOption('onEditorPreparing');
     }
-    set onEditorPreparing(value: ((e: EditorPreparingEvent) => void)) {
+    set onEditorPreparing(value: ((e: EditorPreparingEvent) => void) | undefined) {
         this._setOption('onEditorPreparing', value);
     }
 
@@ -219,10 +219,10 @@ export class DxoCardViewFilterBuilderComponent extends NestedOption implements O
     }
 
     @Input()
-    get onValueChanged(): ((e: ValueChangedEvent) => void) {
+    get onValueChanged(): ((e: ValueChangedEvent) => void) | undefined {
         return this._getOption('onValueChanged');
     }
-    set onValueChanged(value: ((e: ValueChangedEvent) => void)) {
+    set onValueChanged(value: ((e: ValueChangedEvent) => void) | undefined) {
         this._setOption('onValueChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/data-grid/index.ts b/packages/devextreme-angular/src/ui/data-grid/index.ts
index 2fd0024629bb..052e9e2f8b75 100644
--- a/packages/devextreme-angular/src/ui/data-grid/index.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/index.ts
@@ -570,10 +570,10 @@ export class DxDataGridComponent<TRowData = any, TKey = any> extends DxComponent
     
      */
     @Input()
-    get dataSource(): Array<any> | DataSource | DataSourceOptions | null | Store | string {
+    get dataSource(): Array<any> | DataSource | DataSourceOptions | Store | string | undefined {
         return this._getOption('dataSource');
     }
-    set dataSource(value: Array<any> | DataSource | DataSourceOptions | null | Store | string) {
+    set dataSource(value: Array<any> | DataSource | DataSourceOptions | Store | string | undefined) {
         this._setOption('dataSource', value);
     }
 
@@ -609,10 +609,10 @@ export class DxDataGridComponent<TRowData = any, TKey = any> extends DxComponent
     
      */
     @Input()
-    get editing(): { allowAdding?: boolean, allowDeleting?: boolean | ((options: { component: dxDataGrid, row: dxDataGridRowObject }) => boolean), allowUpdating?: boolean | ((options: { component: dxDataGrid, row: dxDataGridRowObject }) => boolean), changes?: Array<DataChange>, confirmDelete?: boolean, editColumnName?: string, editRowKey?: any, form?: dxFormOptions, mode?: GridsEditMode, newRowPosition?: NewRowPosition, popup?: dxPopupOptions<any>, refreshMode?: GridsEditRefreshMode, selectTextOnEditStart?: boolean, startEditAction?: StartEditAction, texts?: any | { addRow?: string, cancelAllChanges?: string, cancelRowChanges?: string, confirmDeleteMessage?: string, confirmDeleteTitle?: string, deleteRow?: string, editRow?: string, saveAllChanges?: string, saveRowChanges?: string, undeleteRow?: string, validationCancelChanges?: string }, useIcons?: boolean } {
+    get editing(): { allowAdding?: boolean, allowDeleting?: boolean | ((options: { component: dxDataGrid, row: dxDataGridRowObject }) => boolean), allowUpdating?: boolean | ((options: { component: dxDataGrid, row: dxDataGridRowObject }) => boolean), changes?: Array<DataChange>, confirmDelete?: boolean, editColumnName?: string | undefined, editRowKey?: any | undefined, form?: dxFormOptions, mode?: GridsEditMode, newRowPosition?: NewRowPosition, popup?: dxPopupOptions<any>, refreshMode?: GridsEditRefreshMode, selectTextOnEditStart?: boolean, startEditAction?: StartEditAction, texts?: any | { addRow?: string, cancelAllChanges?: string, cancelRowChanges?: string, confirmDeleteMessage?: string, confirmDeleteTitle?: string, deleteRow?: string, editRow?: string, saveAllChanges?: string, saveRowChanges?: string, undeleteRow?: string, validationCancelChanges?: string }, useIcons?: boolean } {
         return this._getOption('editing');
     }
-    set editing(value: { allowAdding?: boolean, allowDeleting?: boolean | ((options: { component: dxDataGrid, row: dxDataGridRowObject }) => boolean), allowUpdating?: boolean | ((options: { component: dxDataGrid, row: dxDataGridRowObject }) => boolean), changes?: Array<DataChange>, confirmDelete?: boolean, editColumnName?: string, editRowKey?: any, form?: dxFormOptions, mode?: GridsEditMode, newRowPosition?: NewRowPosition, popup?: dxPopupOptions<any>, refreshMode?: GridsEditRefreshMode, selectTextOnEditStart?: boolean, startEditAction?: StartEditAction, texts?: any | { addRow?: string, cancelAllChanges?: string, cancelRowChanges?: string, confirmDeleteMessage?: string, confirmDeleteTitle?: string, deleteRow?: string, editRow?: string, saveAllChanges?: string, saveRowChanges?: string, undeleteRow?: string, validationCancelChanges?: string }, useIcons?: boolean }) {
+    set editing(value: { allowAdding?: boolean, allowDeleting?: boolean | ((options: { component: dxDataGrid, row: dxDataGridRowObject }) => boolean), allowUpdating?: boolean | ((options: { component: dxDataGrid, row: dxDataGridRowObject }) => boolean), changes?: Array<DataChange>, confirmDelete?: boolean, editColumnName?: string | undefined, editRowKey?: any | undefined, form?: dxFormOptions, mode?: GridsEditMode, newRowPosition?: NewRowPosition, popup?: dxPopupOptions<any>, refreshMode?: GridsEditRefreshMode, selectTextOnEditStart?: boolean, startEditAction?: StartEditAction, texts?: any | { addRow?: string, cancelAllChanges?: string, cancelRowChanges?: string, confirmDeleteMessage?: string, confirmDeleteTitle?: string, deleteRow?: string, editRow?: string, saveAllChanges?: string, saveRowChanges?: string, undeleteRow?: string, validationCancelChanges?: string }, useIcons?: boolean }) {
         this._setOption('editing', value);
     }
 
@@ -1209,10 +1209,10 @@ export class DxDataGridComponent<TRowData = any, TKey = any> extends DxComponent
     
      */
     @Input()
-    get stateStoring(): { customLoad?: Function, customSave?: ((gridState: any) => void), enabled?: boolean, savingTimeout?: number, storageKey?: string, type?: StateStoreType } {
+    get stateStoring(): { customLoad?: Function, customSave?: ((gridState: any) => void), enabled?: boolean, savingTimeout?: number, storageKey?: string | undefined, type?: StateStoreType } {
         return this._getOption('stateStoring');
     }
-    set stateStoring(value: { customLoad?: Function, customSave?: ((gridState: any) => void), enabled?: boolean, savingTimeout?: number, storageKey?: string, type?: StateStoreType }) {
+    set stateStoring(value: { customLoad?: Function, customSave?: ((gridState: any) => void), enabled?: boolean, savingTimeout?: number, storageKey?: string | undefined, type?: StateStoreType }) {
         this._setOption('stateStoring', value);
     }
 
@@ -1802,7 +1802,7 @@ export class DxDataGridComponent<TRowData = any, TKey = any> extends DxComponent
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() dataSourceChange: EventEmitter<Array<any> | DataSource | DataSourceOptions | null | Store | string>;
+    @Output() dataSourceChange: EventEmitter<Array<any> | DataSource | DataSourceOptions | Store | string | undefined>;
 
     /**
     
@@ -1823,7 +1823,7 @@ export class DxDataGridComponent<TRowData = any, TKey = any> extends DxComponent
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() editingChange: EventEmitter<{ allowAdding?: boolean, allowDeleting?: boolean | ((options: { component: dxDataGrid, row: dxDataGridRowObject }) => boolean), allowUpdating?: boolean | ((options: { component: dxDataGrid, row: dxDataGridRowObject }) => boolean), changes?: Array<DataChange>, confirmDelete?: boolean, editColumnName?: string, editRowKey?: any, form?: dxFormOptions, mode?: GridsEditMode, newRowPosition?: NewRowPosition, popup?: dxPopupOptions<any>, refreshMode?: GridsEditRefreshMode, selectTextOnEditStart?: boolean, startEditAction?: StartEditAction, texts?: any | { addRow?: string, cancelAllChanges?: string, cancelRowChanges?: string, confirmDeleteMessage?: string, confirmDeleteTitle?: string, deleteRow?: string, editRow?: string, saveAllChanges?: string, saveRowChanges?: string, undeleteRow?: string, validationCancelChanges?: string }, useIcons?: boolean }>;
+    @Output() editingChange: EventEmitter<{ allowAdding?: boolean, allowDeleting?: boolean | ((options: { component: dxDataGrid, row: dxDataGridRowObject }) => boolean), allowUpdating?: boolean | ((options: { component: dxDataGrid, row: dxDataGridRowObject }) => boolean), changes?: Array<DataChange>, confirmDelete?: boolean, editColumnName?: string | undefined, editRowKey?: any | undefined, form?: dxFormOptions, mode?: GridsEditMode, newRowPosition?: NewRowPosition, popup?: dxPopupOptions<any>, refreshMode?: GridsEditRefreshMode, selectTextOnEditStart?: boolean, startEditAction?: StartEditAction, texts?: any | { addRow?: string, cancelAllChanges?: string, cancelRowChanges?: string, confirmDeleteMessage?: string, confirmDeleteTitle?: string, deleteRow?: string, editRow?: string, saveAllChanges?: string, saveRowChanges?: string, undeleteRow?: string, validationCancelChanges?: string }, useIcons?: boolean }>;
 
     /**
     
@@ -2145,7 +2145,7 @@ export class DxDataGridComponent<TRowData = any, TKey = any> extends DxComponent
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() stateStoringChange: EventEmitter<{ customLoad?: Function, customSave?: ((gridState: any) => void), enabled?: boolean, savingTimeout?: number, storageKey?: string, type?: StateStoreType }>;
+    @Output() stateStoringChange: EventEmitter<{ customLoad?: Function, customSave?: ((gridState: any) => void), enabled?: boolean, savingTimeout?: number, storageKey?: string | undefined, type?: StateStoreType }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/editing.ts b/packages/devextreme-angular/src/ui/data-grid/nested/editing.ts
index 64a02cedfc25..a5c0b6774512 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/editing.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/editing.ts
@@ -88,18 +88,18 @@ export class DxoDataGridEditingComponent extends NestedOption implements OnDestr
     }
 
     @Input()
-    get editColumnName(): string {
+    get editColumnName(): string | undefined {
         return this._getOption('editColumnName');
     }
-    set editColumnName(value: string) {
+    set editColumnName(value: string | undefined) {
         this._setOption('editColumnName', value);
     }
 
     @Input()
-    get editRowKey(): any {
+    get editRowKey(): any | undefined {
         return this._getOption('editRowKey');
     }
-    set editRowKey(value: any) {
+    set editRowKey(value: any | undefined) {
         this._setOption('editRowKey', value);
     }
 
@@ -188,14 +188,14 @@ export class DxoDataGridEditingComponent extends NestedOption implements OnDestr
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() editColumnNameChange: EventEmitter<string>;
+    @Output() editColumnNameChange: EventEmitter<string | undefined>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() editRowKeyChange: EventEmitter<any>;
+    @Output() editRowKeyChange: EventEmitter<any | undefined>;
     protected get _optionPath() {
         return 'editing';
     }
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/filter-builder.ts b/packages/devextreme-angular/src/ui/data-grid/nested/filter-builder.ts
index 86340a29362d..a47a9b6b883b 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/filter-builder.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/filter-builder.ts
@@ -187,18 +187,18 @@ export class DxoDataGridFilterBuilderComponent extends NestedOption implements O
     }
 
     @Input()
-    get onEditorPrepared(): ((e: EditorPreparedEvent) => void) {
+    get onEditorPrepared(): ((e: EditorPreparedEvent) => void) | undefined {
         return this._getOption('onEditorPrepared');
     }
-    set onEditorPrepared(value: ((e: EditorPreparedEvent) => void)) {
+    set onEditorPrepared(value: ((e: EditorPreparedEvent) => void) | undefined) {
         this._setOption('onEditorPrepared', value);
     }
 
     @Input()
-    get onEditorPreparing(): ((e: EditorPreparingEvent) => void) {
+    get onEditorPreparing(): ((e: EditorPreparingEvent) => void) | undefined {
         return this._getOption('onEditorPreparing');
     }
-    set onEditorPreparing(value: ((e: EditorPreparingEvent) => void)) {
+    set onEditorPreparing(value: ((e: EditorPreparingEvent) => void) | undefined) {
         this._setOption('onEditorPreparing', value);
     }
 
@@ -219,10 +219,10 @@ export class DxoDataGridFilterBuilderComponent extends NestedOption implements O
     }
 
     @Input()
-    get onValueChanged(): ((e: ValueChangedEvent) => void) {
+    get onValueChanged(): ((e: ValueChangedEvent) => void) | undefined {
         return this._getOption('onValueChanged');
     }
-    set onValueChanged(value: ((e: ValueChangedEvent) => void)) {
+    set onValueChanged(value: ((e: ValueChangedEvent) => void) | undefined) {
         this._setOption('onValueChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/state-storing.ts b/packages/devextreme-angular/src/ui/data-grid/nested/state-storing.ts
index 64cd671dc8bc..9603535b9c88 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/state-storing.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/state-storing.ts
@@ -64,10 +64,10 @@ export class DxoDataGridStateStoringComponent extends NestedOption implements On
     }
 
     @Input()
-    get storageKey(): string {
+    get storageKey(): string | undefined {
         return this._getOption('storageKey');
     }
-    set storageKey(value: string) {
+    set storageKey(value: string | undefined) {
         this._setOption('storageKey', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/list/nested/item-dragging.ts b/packages/devextreme-angular/src/ui/list/nested/item-dragging.ts
index c3baf6f32520..947d57b10f7d 100644
--- a/packages/devextreme-angular/src/ui/list/nested/item-dragging.ts
+++ b/packages/devextreme-angular/src/ui/list/nested/item-dragging.ts
@@ -169,10 +169,10 @@ export class DxoListItemDraggingComponent extends NestedOption implements OnDest
     }
 
     @Input()
-    get onAdd(): ((e: AddEvent) => void) {
+    get onAdd(): ((e: AddEvent) => void) | undefined {
         return this._getOption('onAdd');
     }
-    set onAdd(value: ((e: AddEvent) => void)) {
+    set onAdd(value: ((e: AddEvent) => void) | undefined) {
         this._setOption('onAdd', value);
     }
 
@@ -185,34 +185,34 @@ export class DxoListItemDraggingComponent extends NestedOption implements OnDest
     }
 
     @Input()
-    get onDragChange(): ((e: DragChangeEvent) => void) {
+    get onDragChange(): ((e: DragChangeEvent) => void) | undefined {
         return this._getOption('onDragChange');
     }
-    set onDragChange(value: ((e: DragChangeEvent) => void)) {
+    set onDragChange(value: ((e: DragChangeEvent) => void) | undefined) {
         this._setOption('onDragChange', value);
     }
 
     @Input()
-    get onDragEnd(): ((e: DragEndEvent) => void) {
+    get onDragEnd(): ((e: DragEndEvent) => void) | undefined {
         return this._getOption('onDragEnd');
     }
-    set onDragEnd(value: ((e: DragEndEvent) => void)) {
+    set onDragEnd(value: ((e: DragEndEvent) => void) | undefined) {
         this._setOption('onDragEnd', value);
     }
 
     @Input()
-    get onDragMove(): ((e: DragMoveEvent) => void) {
+    get onDragMove(): ((e: DragMoveEvent) => void) | undefined {
         return this._getOption('onDragMove');
     }
-    set onDragMove(value: ((e: DragMoveEvent) => void)) {
+    set onDragMove(value: ((e: DragMoveEvent) => void) | undefined) {
         this._setOption('onDragMove', value);
     }
 
     @Input()
-    get onDragStart(): ((e: DragStartEvent) => void) {
+    get onDragStart(): ((e: DragStartEvent) => void) | undefined {
         return this._getOption('onDragStart');
     }
-    set onDragStart(value: ((e: DragStartEvent) => void)) {
+    set onDragStart(value: ((e: DragStartEvent) => void) | undefined) {
         this._setOption('onDragStart', value);
     }
 
@@ -233,18 +233,18 @@ export class DxoListItemDraggingComponent extends NestedOption implements OnDest
     }
 
     @Input()
-    get onRemove(): ((e: RemoveEvent) => void) {
+    get onRemove(): ((e: RemoveEvent) => void) | undefined {
         return this._getOption('onRemove');
     }
-    set onRemove(value: ((e: RemoveEvent) => void)) {
+    set onRemove(value: ((e: RemoveEvent) => void) | undefined) {
         this._setOption('onRemove', value);
     }
 
     @Input()
-    get onReorder(): ((e: ReorderEvent) => void) {
+    get onReorder(): ((e: ReorderEvent) => void) | undefined {
         return this._getOption('onReorder');
     }
-    set onReorder(value: ((e: ReorderEvent) => void)) {
+    set onReorder(value: ((e: ReorderEvent) => void) | undefined) {
         this._setOption('onReorder', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/editing.ts b/packages/devextreme-angular/src/ui/nested/editing.ts
index 59fe62f432b3..d613de9b97f4 100644
--- a/packages/devextreme-angular/src/ui/nested/editing.ts
+++ b/packages/devextreme-angular/src/ui/nested/editing.ts
@@ -87,18 +87,18 @@ export class DxoEditingComponent extends NestedOption implements OnDestroy, OnIn
     }
 
     @Input()
-    get editColumnName(): string {
+    get editColumnName(): string | undefined {
         return this._getOption('editColumnName');
     }
-    set editColumnName(value: string) {
+    set editColumnName(value: string | undefined) {
         this._setOption('editColumnName', value);
     }
 
     @Input()
-    get editRowKey(): any {
+    get editRowKey(): any | undefined {
         return this._getOption('editRowKey');
     }
-    set editRowKey(value: any) {
+    set editRowKey(value: any | undefined) {
         this._setOption('editRowKey', value);
     }
 
@@ -363,14 +363,14 @@ export class DxoEditingComponent extends NestedOption implements OnDestroy, OnIn
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() editColumnNameChange: EventEmitter<string>;
+    @Output() editColumnNameChange: EventEmitter<string | undefined>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() editRowKeyChange: EventEmitter<any>;
+    @Output() editRowKeyChange: EventEmitter<any | undefined>;
     protected get _optionPath() {
         return 'editing';
     }
diff --git a/packages/devextreme-angular/src/ui/nested/state-storing.ts b/packages/devextreme-angular/src/ui/nested/state-storing.ts
index 89f9ee5fdc9d..f9dc97937748 100644
--- a/packages/devextreme-angular/src/ui/nested/state-storing.ts
+++ b/packages/devextreme-angular/src/ui/nested/state-storing.ts
@@ -64,10 +64,10 @@ export class DxoStateStoringComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get storageKey(): string {
+    get storageKey(): string | undefined {
         return this._getOption('storageKey');
     }
-    set storageKey(value: string) {
+    set storageKey(value: string | undefined) {
         this._setOption('storageKey', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-list/index.ts b/packages/devextreme-angular/src/ui/tree-list/index.ts
index 9b97579a5597..afbe2380d955 100644
--- a/packages/devextreme-angular/src/ui/tree-list/index.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/index.ts
@@ -527,10 +527,10 @@ export class DxTreeListComponent<TRowData = any, TKey = any> extends DxComponent
     
      */
     @Input()
-    get dataSource(): Array<any> | DataSource | DataSourceOptions | null | Store | string {
+    get dataSource(): Array<any> | DataSource | DataSourceOptions | Store | string | undefined {
         return this._getOption('dataSource');
     }
-    set dataSource(value: Array<any> | DataSource | DataSourceOptions | null | Store | string) {
+    set dataSource(value: Array<any> | DataSource | DataSourceOptions | Store | string | undefined) {
         this._setOption('dataSource', value);
     }
 
@@ -579,10 +579,10 @@ export class DxTreeListComponent<TRowData = any, TKey = any> extends DxComponent
     
      */
     @Input()
-    get editing(): { allowAdding?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), allowDeleting?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), allowUpdating?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), changes?: Array<DataChange>, confirmDelete?: boolean, editColumnName?: string, editRowKey?: any, form?: dxFormOptions, mode?: GridsEditMode, popup?: dxPopupOptions<any>, refreshMode?: GridsEditRefreshMode, selectTextOnEditStart?: boolean, startEditAction?: StartEditAction, texts?: { addRow?: string, addRowToNode?: string, cancelAllChanges?: string, cancelRowChanges?: string, confirmDeleteMessage?: string, confirmDeleteTitle?: string, deleteRow?: string, editRow?: string, saveAllChanges?: string, saveRowChanges?: string, undeleteRow?: string, validationCancelChanges?: string }, useIcons?: boolean } {
+    get editing(): { allowAdding?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), allowDeleting?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), allowUpdating?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), changes?: Array<DataChange>, confirmDelete?: boolean, editColumnName?: string | undefined, editRowKey?: any | undefined, form?: dxFormOptions, mode?: GridsEditMode, popup?: dxPopupOptions<any>, refreshMode?: GridsEditRefreshMode, selectTextOnEditStart?: boolean, startEditAction?: StartEditAction, texts?: { addRow?: string, addRowToNode?: string, cancelAllChanges?: string, cancelRowChanges?: string, confirmDeleteMessage?: string, confirmDeleteTitle?: string, deleteRow?: string, editRow?: string, saveAllChanges?: string, saveRowChanges?: string, undeleteRow?: string, validationCancelChanges?: string }, useIcons?: boolean } {
         return this._getOption('editing');
     }
-    set editing(value: { allowAdding?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), allowDeleting?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), allowUpdating?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), changes?: Array<DataChange>, confirmDelete?: boolean, editColumnName?: string, editRowKey?: any, form?: dxFormOptions, mode?: GridsEditMode, popup?: dxPopupOptions<any>, refreshMode?: GridsEditRefreshMode, selectTextOnEditStart?: boolean, startEditAction?: StartEditAction, texts?: { addRow?: string, addRowToNode?: string, cancelAllChanges?: string, cancelRowChanges?: string, confirmDeleteMessage?: string, confirmDeleteTitle?: string, deleteRow?: string, editRow?: string, saveAllChanges?: string, saveRowChanges?: string, undeleteRow?: string, validationCancelChanges?: string }, useIcons?: boolean }) {
+    set editing(value: { allowAdding?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), allowDeleting?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), allowUpdating?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), changes?: Array<DataChange>, confirmDelete?: boolean, editColumnName?: string | undefined, editRowKey?: any | undefined, form?: dxFormOptions, mode?: GridsEditMode, popup?: dxPopupOptions<any>, refreshMode?: GridsEditRefreshMode, selectTextOnEditStart?: boolean, startEditAction?: StartEditAction, texts?: { addRow?: string, addRowToNode?: string, cancelAllChanges?: string, cancelRowChanges?: string, confirmDeleteMessage?: string, confirmDeleteTitle?: string, deleteRow?: string, editRow?: string, saveAllChanges?: string, saveRowChanges?: string, undeleteRow?: string, validationCancelChanges?: string }, useIcons?: boolean }) {
         this._setOption('editing', value);
     }
 
@@ -1177,10 +1177,10 @@ export class DxTreeListComponent<TRowData = any, TKey = any> extends DxComponent
     
      */
     @Input()
-    get stateStoring(): { customLoad?: Function, customSave?: ((gridState: any) => void), enabled?: boolean, savingTimeout?: number, storageKey?: string, type?: StateStoreType } {
+    get stateStoring(): { customLoad?: Function, customSave?: ((gridState: any) => void), enabled?: boolean, savingTimeout?: number, storageKey?: string | undefined, type?: StateStoreType } {
         return this._getOption('stateStoring');
     }
-    set stateStoring(value: { customLoad?: Function, customSave?: ((gridState: any) => void), enabled?: boolean, savingTimeout?: number, storageKey?: string, type?: StateStoreType }) {
+    set stateStoring(value: { customLoad?: Function, customSave?: ((gridState: any) => void), enabled?: boolean, savingTimeout?: number, storageKey?: string | undefined, type?: StateStoreType }) {
         this._setOption('stateStoring', value);
     }
 
@@ -1757,7 +1757,7 @@ export class DxTreeListComponent<TRowData = any, TKey = any> extends DxComponent
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() dataSourceChange: EventEmitter<Array<any> | DataSource | DataSourceOptions | null | Store | string>;
+    @Output() dataSourceChange: EventEmitter<Array<any> | DataSource | DataSourceOptions | Store | string | undefined>;
 
     /**
     
@@ -1785,7 +1785,7 @@ export class DxTreeListComponent<TRowData = any, TKey = any> extends DxComponent
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() editingChange: EventEmitter<{ allowAdding?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), allowDeleting?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), allowUpdating?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), changes?: Array<DataChange>, confirmDelete?: boolean, editColumnName?: string, editRowKey?: any, form?: dxFormOptions, mode?: GridsEditMode, popup?: dxPopupOptions<any>, refreshMode?: GridsEditRefreshMode, selectTextOnEditStart?: boolean, startEditAction?: StartEditAction, texts?: { addRow?: string, addRowToNode?: string, cancelAllChanges?: string, cancelRowChanges?: string, confirmDeleteMessage?: string, confirmDeleteTitle?: string, deleteRow?: string, editRow?: string, saveAllChanges?: string, saveRowChanges?: string, undeleteRow?: string, validationCancelChanges?: string }, useIcons?: boolean }>;
+    @Output() editingChange: EventEmitter<{ allowAdding?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), allowDeleting?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), allowUpdating?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean), changes?: Array<DataChange>, confirmDelete?: boolean, editColumnName?: string | undefined, editRowKey?: any | undefined, form?: dxFormOptions, mode?: GridsEditMode, popup?: dxPopupOptions<any>, refreshMode?: GridsEditRefreshMode, selectTextOnEditStart?: boolean, startEditAction?: StartEditAction, texts?: { addRow?: string, addRowToNode?: string, cancelAllChanges?: string, cancelRowChanges?: string, confirmDeleteMessage?: string, confirmDeleteTitle?: string, deleteRow?: string, editRow?: string, saveAllChanges?: string, saveRowChanges?: string, undeleteRow?: string, validationCancelChanges?: string }, useIcons?: boolean }>;
 
     /**
     
@@ -2107,7 +2107,7 @@ export class DxTreeListComponent<TRowData = any, TKey = any> extends DxComponent
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() stateStoringChange: EventEmitter<{ customLoad?: Function, customSave?: ((gridState: any) => void), enabled?: boolean, savingTimeout?: number, storageKey?: string, type?: StateStoreType }>;
+    @Output() stateStoringChange: EventEmitter<{ customLoad?: Function, customSave?: ((gridState: any) => void), enabled?: boolean, savingTimeout?: number, storageKey?: string | undefined, type?: StateStoreType }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/editing.ts b/packages/devextreme-angular/src/ui/tree-list/nested/editing.ts
index f8b187f9b4fb..c6c4c82dec8d 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/editing.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/editing.ts
@@ -88,18 +88,18 @@ export class DxoTreeListEditingComponent extends NestedOption implements OnDestr
     }
 
     @Input()
-    get editColumnName(): string {
+    get editColumnName(): string | undefined {
         return this._getOption('editColumnName');
     }
-    set editColumnName(value: string) {
+    set editColumnName(value: string | undefined) {
         this._setOption('editColumnName', value);
     }
 
     @Input()
-    get editRowKey(): any {
+    get editRowKey(): any | undefined {
         return this._getOption('editRowKey');
     }
-    set editRowKey(value: any) {
+    set editRowKey(value: any | undefined) {
         this._setOption('editRowKey', value);
     }
 
@@ -180,14 +180,14 @@ export class DxoTreeListEditingComponent extends NestedOption implements OnDestr
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() editColumnNameChange: EventEmitter<string>;
+    @Output() editColumnNameChange: EventEmitter<string | undefined>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() editRowKeyChange: EventEmitter<any>;
+    @Output() editRowKeyChange: EventEmitter<any | undefined>;
     protected get _optionPath() {
         return 'editing';
     }
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/filter-builder.ts b/packages/devextreme-angular/src/ui/tree-list/nested/filter-builder.ts
index 932d72422c6f..236d1df4f6a4 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/filter-builder.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/filter-builder.ts
@@ -187,18 +187,18 @@ export class DxoTreeListFilterBuilderComponent extends NestedOption implements O
     }
 
     @Input()
-    get onEditorPrepared(): ((e: EditorPreparedEvent) => void) {
+    get onEditorPrepared(): ((e: EditorPreparedEvent) => void) | undefined {
         return this._getOption('onEditorPrepared');
     }
-    set onEditorPrepared(value: ((e: EditorPreparedEvent) => void)) {
+    set onEditorPrepared(value: ((e: EditorPreparedEvent) => void) | undefined) {
         this._setOption('onEditorPrepared', value);
     }
 
     @Input()
-    get onEditorPreparing(): ((e: EditorPreparingEvent) => void) {
+    get onEditorPreparing(): ((e: EditorPreparingEvent) => void) | undefined {
         return this._getOption('onEditorPreparing');
     }
-    set onEditorPreparing(value: ((e: EditorPreparingEvent) => void)) {
+    set onEditorPreparing(value: ((e: EditorPreparingEvent) => void) | undefined) {
         this._setOption('onEditorPreparing', value);
     }
 
@@ -219,10 +219,10 @@ export class DxoTreeListFilterBuilderComponent extends NestedOption implements O
     }
 
     @Input()
-    get onValueChanged(): ((e: ValueChangedEvent) => void) {
+    get onValueChanged(): ((e: ValueChangedEvent) => void) | undefined {
         return this._getOption('onValueChanged');
     }
-    set onValueChanged(value: ((e: ValueChangedEvent) => void)) {
+    set onValueChanged(value: ((e: ValueChangedEvent) => void) | undefined) {
         this._setOption('onValueChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/state-storing.ts b/packages/devextreme-angular/src/ui/tree-list/nested/state-storing.ts
index 95398d71dcda..7f8562ef4335 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/state-storing.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/state-storing.ts
@@ -64,10 +64,10 @@ export class DxoTreeListStateStoringComponent extends NestedOption implements On
     }
 
     @Input()
-    get storageKey(): string {
+    get storageKey(): string | undefined {
         return this._getOption('storageKey');
     }
-    set storageKey(value: string) {
+    set storageKey(value: string | undefined) {
         this._setOption('storageKey', value);
     }
 
diff --git a/packages/devextreme-react/src/card-view.ts b/packages/devextreme-react/src/card-view.ts
index c4c8c18ad6c0..4cf1b45263e7 100644
--- a/packages/devextreme-react/src/card-view.ts
+++ b/packages/devextreme-react/src/card-view.ts
@@ -1172,11 +1172,11 @@ type IFilterBuilderProps = React.PropsWithChildren<{
   maxGroupLevel?: number | undefined;
   onContentReady?: ((e: FilterBuilderContentReadyEvent) => void);
   onDisposing?: ((e: FilterBuilderDisposingEvent) => void);
-  onEditorPrepared?: ((e: EditorPreparedEvent) => void);
-  onEditorPreparing?: ((e: EditorPreparingEvent) => void);
+  onEditorPrepared?: ((e: EditorPreparedEvent) => void) | undefined;
+  onEditorPreparing?: ((e: EditorPreparingEvent) => void) | undefined;
   onInitialized?: ((e: FilterBuilderInitializedEvent) => void);
   onOptionChanged?: ((e: FilterBuilderOptionChangedEvent) => void);
-  onValueChanged?: ((e: ValueChangedEvent) => void);
+  onValueChanged?: ((e: ValueChangedEvent) => void) | undefined;
   rtlEnabled?: boolean;
   tabIndex?: number;
   value?: Array<any> | (() => any) | string;
diff --git a/packages/devextreme-react/src/data-grid.ts b/packages/devextreme-react/src/data-grid.ts
index 4224156bb62e..285e527e5e4d 100644
--- a/packages/devextreme-react/src/data-grid.ts
+++ b/packages/devextreme-react/src/data-grid.ts
@@ -1220,8 +1220,8 @@ type IEditingProps = React.PropsWithChildren<{
   allowUpdating?: boolean | ((options: { component: dxDataGrid, row: dxDataGridRowObject }) => boolean);
   changes?: Array<DataChange>;
   confirmDelete?: boolean;
-  editColumnName?: string;
-  editRowKey?: any;
+  editColumnName?: string | undefined;
+  editRowKey?: any | undefined;
   form?: dxFormOptions;
   mode?: GridsEditMode;
   newRowPosition?: NewRowPosition;
@@ -1245,10 +1245,10 @@ type IEditingProps = React.PropsWithChildren<{
   useIcons?: boolean;
   defaultChanges?: Array<DataChange>;
   onChangesChange?: (value: Array<DataChange>) => void;
-  defaultEditColumnName?: string;
-  onEditColumnNameChange?: (value: string) => void;
-  defaultEditRowKey?: any;
-  onEditRowKeyChange?: (value: any) => void;
+  defaultEditColumnName?: string | undefined;
+  onEditColumnNameChange?: (value: string | undefined) => void;
+  defaultEditRowKey?: any | undefined;
+  onEditRowKeyChange?: (value: any | undefined) => void;
 }>
 const _componentEditing = (props: IEditingProps) => {
   return React.createElement(NestedOption<IEditingProps>, {
@@ -1618,11 +1618,11 @@ type IFilterBuilderProps = React.PropsWithChildren<{
   maxGroupLevel?: number | undefined;
   onContentReady?: ((e: FilterBuilderContentReadyEvent) => void);
   onDisposing?: ((e: FilterBuilderDisposingEvent) => void);
-  onEditorPrepared?: ((e: FilterBuilderEditorPreparedEvent) => void);
-  onEditorPreparing?: ((e: FilterBuilderEditorPreparingEvent) => void);
+  onEditorPrepared?: ((e: FilterBuilderEditorPreparedEvent) => void) | undefined;
+  onEditorPreparing?: ((e: FilterBuilderEditorPreparingEvent) => void) | undefined;
   onInitialized?: ((e: FilterBuilderInitializedEvent) => void);
   onOptionChanged?: ((e: FilterBuilderOptionChangedEvent) => void);
-  onValueChanged?: ((e: FilterBuilderValueChangedEvent) => void);
+  onValueChanged?: ((e: FilterBuilderValueChangedEvent) => void) | undefined;
   rtlEnabled?: boolean;
   tabIndex?: number;
   value?: Array<any> | (() => any) | string;
@@ -3382,7 +3382,7 @@ type IStateStoringProps = React.PropsWithChildren<{
   customSave?: ((gridState: any) => void);
   enabled?: boolean;
   savingTimeout?: number;
-  storageKey?: string;
+  storageKey?: string | undefined;
   type?: StateStoreType;
 }>
 const _componentStateStoring = (props: IStateStoringProps) => {
diff --git a/packages/devextreme-react/src/draggable.ts b/packages/devextreme-react/src/draggable.ts
index 3122e5a6a2f8..492c033e4961 100644
--- a/packages/devextreme-react/src/draggable.ts
+++ b/packages/devextreme-react/src/draggable.ts
@@ -16,9 +16,9 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 
 type IDraggableOptionsNarrowedEvents = {
   onDisposing?: ((e: DisposingEvent) => void);
-  onDragEnd?: ((e: DragEndEvent) => void);
-  onDragMove?: ((e: DragMoveEvent) => void);
-  onDragStart?: ((e: DragStartEvent) => void);
+  onDragEnd?: ((e: DragEndEvent) => void) | undefined;
+  onDragMove?: ((e: DragMoveEvent) => void) | undefined;
+  onDragStart?: ((e: DragStartEvent) => void) | undefined;
   onInitialized?: ((e: InitializedEvent) => void);
 }
 
diff --git a/packages/devextreme-react/src/filter-builder.ts b/packages/devextreme-react/src/filter-builder.ts
index a8d6be7357f6..7c4e2bffbd77 100644
--- a/packages/devextreme-react/src/filter-builder.ts
+++ b/packages/devextreme-react/src/filter-builder.ts
@@ -21,10 +21,10 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 type IFilterBuilderOptionsNarrowedEvents = {
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
-  onEditorPrepared?: ((e: EditorPreparedEvent) => void);
-  onEditorPreparing?: ((e: EditorPreparingEvent) => void);
+  onEditorPrepared?: ((e: EditorPreparedEvent) => void) | undefined;
+  onEditorPreparing?: ((e: EditorPreparingEvent) => void) | undefined;
   onInitialized?: ((e: InitializedEvent) => void);
-  onValueChanged?: ((e: ValueChangedEvent) => void);
+  onValueChanged?: ((e: ValueChangedEvent) => void) | undefined;
 }
 
 type IFilterBuilderOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IFilterBuilderOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/list.ts b/packages/devextreme-react/src/list.ts
index 9514436e019e..5d9a88eff606 100644
--- a/packages/devextreme-react/src/list.ts
+++ b/packages/devextreme-react/src/list.ts
@@ -217,16 +217,16 @@ type IItemDraggingProps = React.PropsWithChildren<{
   height?: number | string | undefined;
   itemOrientation?: Orientation;
   moveItemOnDrop?: boolean;
-  onAdd?: ((e: AddEvent) => void);
+  onAdd?: ((e: AddEvent) => void) | undefined;
   onDisposing?: ((e: SortableDisposingEvent) => void);
-  onDragChange?: ((e: DragChangeEvent) => void);
-  onDragEnd?: ((e: DragEndEvent) => void);
-  onDragMove?: ((e: DragMoveEvent) => void);
-  onDragStart?: ((e: DragStartEvent) => void);
+  onDragChange?: ((e: DragChangeEvent) => void) | undefined;
+  onDragEnd?: ((e: DragEndEvent) => void) | undefined;
+  onDragMove?: ((e: DragMoveEvent) => void) | undefined;
+  onDragStart?: ((e: DragStartEvent) => void) | undefined;
   onInitialized?: ((e: SortableInitializedEvent) => void);
   onOptionChanged?: ((e: OptionChangedEvent) => void);
-  onRemove?: ((e: RemoveEvent) => void);
-  onReorder?: ((e: ReorderEvent) => void);
+  onRemove?: ((e: RemoveEvent) => void) | undefined;
+  onReorder?: ((e: ReorderEvent) => void) | undefined;
   rtlEnabled?: boolean;
   scrollSensitivity?: number;
   scrollSpeed?: number;
diff --git a/packages/devextreme-react/src/sortable.ts b/packages/devextreme-react/src/sortable.ts
index bdfd07424b92..d2f5b9a1d7b2 100644
--- a/packages/devextreme-react/src/sortable.ts
+++ b/packages/devextreme-react/src/sortable.ts
@@ -15,15 +15,15 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 }
 
 type ISortableOptionsNarrowedEvents = {
-  onAdd?: ((e: AddEvent) => void);
+  onAdd?: ((e: AddEvent) => void) | undefined;
   onDisposing?: ((e: DisposingEvent) => void);
-  onDragChange?: ((e: DragChangeEvent) => void);
-  onDragEnd?: ((e: DragEndEvent) => void);
-  onDragMove?: ((e: DragMoveEvent) => void);
-  onDragStart?: ((e: DragStartEvent) => void);
+  onDragChange?: ((e: DragChangeEvent) => void) | undefined;
+  onDragEnd?: ((e: DragEndEvent) => void) | undefined;
+  onDragMove?: ((e: DragMoveEvent) => void) | undefined;
+  onDragStart?: ((e: DragStartEvent) => void) | undefined;
   onInitialized?: ((e: InitializedEvent) => void);
-  onRemove?: ((e: RemoveEvent) => void);
-  onReorder?: ((e: ReorderEvent) => void);
+  onRemove?: ((e: RemoveEvent) => void) | undefined;
+  onReorder?: ((e: ReorderEvent) => void) | undefined;
 }
 
 type ISortableOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, ISortableOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/tree-list.ts b/packages/devextreme-react/src/tree-list.ts
index 5a6d53ae3ffc..25acb626d9eb 100644
--- a/packages/devextreme-react/src/tree-list.ts
+++ b/packages/devextreme-react/src/tree-list.ts
@@ -1037,8 +1037,8 @@ type IEditingProps = React.PropsWithChildren<{
   allowUpdating?: boolean | ((options: { component: dxTreeList, row: dxTreeListRowObject }) => boolean);
   changes?: Array<DataChange>;
   confirmDelete?: boolean;
-  editColumnName?: string;
-  editRowKey?: any;
+  editColumnName?: string | undefined;
+  editRowKey?: any | undefined;
   form?: dxFormOptions;
   mode?: GridsEditMode;
   popup?: dxPopupOptions<any>;
@@ -1062,10 +1062,10 @@ type IEditingProps = React.PropsWithChildren<{
   useIcons?: boolean;
   defaultChanges?: Array<DataChange>;
   onChangesChange?: (value: Array<DataChange>) => void;
-  defaultEditColumnName?: string;
-  onEditColumnNameChange?: (value: string) => void;
-  defaultEditRowKey?: any;
-  onEditRowKeyChange?: (value: any) => void;
+  defaultEditColumnName?: string | undefined;
+  onEditColumnNameChange?: (value: string | undefined) => void;
+  defaultEditRowKey?: any | undefined;
+  onEditRowKeyChange?: (value: any | undefined) => void;
 }>
 const _componentEditing = (props: IEditingProps) => {
   return React.createElement(NestedOption<IEditingProps>, {
@@ -1387,11 +1387,11 @@ type IFilterBuilderProps = React.PropsWithChildren<{
   maxGroupLevel?: number | undefined;
   onContentReady?: ((e: FilterBuilderContentReadyEvent) => void);
   onDisposing?: ((e: FilterBuilderDisposingEvent) => void);
-  onEditorPrepared?: ((e: FilterBuilderEditorPreparedEvent) => void);
-  onEditorPreparing?: ((e: FilterBuilderEditorPreparingEvent) => void);
+  onEditorPrepared?: ((e: FilterBuilderEditorPreparedEvent) => void) | undefined;
+  onEditorPreparing?: ((e: FilterBuilderEditorPreparingEvent) => void) | undefined;
   onInitialized?: ((e: FilterBuilderInitializedEvent) => void);
   onOptionChanged?: ((e: FilterBuilderOptionChangedEvent) => void);
-  onValueChanged?: ((e: FilterBuilderValueChangedEvent) => void);
+  onValueChanged?: ((e: FilterBuilderValueChangedEvent) => void) | undefined;
   rtlEnabled?: boolean;
   tabIndex?: number;
   value?: Array<any> | (() => any) | string;
@@ -2986,7 +2986,7 @@ type IStateStoringProps = React.PropsWithChildren<{
   customSave?: ((gridState: any) => void);
   enabled?: boolean;
   savingTimeout?: number;
-  storageKey?: string;
+  storageKey?: string | undefined;
   type?: StateStoreType;
 }>
 const _componentStateStoring = (props: IStateStoringProps) => {
diff --git a/packages/devextreme-vue/src/data-grid.ts b/packages/devextreme-vue/src/data-grid.ts
index 56a5258d1881..7eb39a9740a6 100644
--- a/packages/devextreme-vue/src/data-grid.ts
+++ b/packages/devextreme-vue/src/data-grid.ts
@@ -423,7 +423,7 @@ const componentConfig = {
     columnWidth: [String, Number] as PropType<Mode | number>,
     customizeColumns: Function as PropType<((columns: Array<dxDataGridColumn>) => void)>,
     dataRowTemplate: {},
-    dataSource: [Array, Object, String] as PropType<Array<any> | DataSource | DataSourceOptions | null | Store | string | Record<string, any>>,
+    dataSource: [Array, Object, String] as PropType<Array<any> | DataSource | DataSourceOptions | Store | string | Record<string, any>>,
     dateSerializationFormat: String,
     disabled: Boolean,
     editing: Object as PropType<Record<string, any>>,
diff --git a/packages/devextreme-vue/src/tree-list.ts b/packages/devextreme-vue/src/tree-list.ts
index 945e4e273a83..a6abed1aea26 100644
--- a/packages/devextreme-vue/src/tree-list.ts
+++ b/packages/devextreme-vue/src/tree-list.ts
@@ -418,7 +418,7 @@ const componentConfig = {
     columns: Array as PropType<Array<dxTreeListColumn | string>>,
     columnWidth: [String, Number] as PropType<Mode | number>,
     customizeColumns: Function as PropType<((columns: Array<dxTreeListColumn>) => void)>,
-    dataSource: [Array, Object, String] as PropType<Array<any> | DataSource | DataSourceOptions | null | Store | string | Record<string, any>>,
+    dataSource: [Array, Object, String] as PropType<Array<any> | DataSource | DataSourceOptions | Store | string | Record<string, any>>,
     dataStructure: String as PropType<DataStructure>,
     dateSerializationFormat: String,
     disabled: Boolean,
diff --git a/packages/devextreme/js/__internal/filter_builder/m_filter_builder.ts b/packages/devextreme/js/__internal/filter_builder/m_filter_builder.ts
index 53d37766067f..778dcb14c85b 100644
--- a/packages/devextreme/js/__internal/filter_builder/m_filter_builder.ts
+++ b/packages/devextreme/js/__internal/filter_builder/m_filter_builder.ts
@@ -97,11 +97,11 @@ class FilterBuilder extends Widget<any> {
   _getDefaultOptions() {
     // @ts-expect-error
     return extend(super._getDefaultOptions(), {
-      onEditorPreparing: null,
+      onEditorPreparing: undefined,
 
-      onEditorPrepared: null,
+      onEditorPrepared: undefined,
 
-      onValueChanged: null,
+      onValueChanged: undefined,
 
       fields: [],
 
diff --git a/packages/devextreme/js/__internal/grids/grid_core/adaptivity/m_adaptivity.ts b/packages/devextreme/js/__internal/grids/grid_core/adaptivity/m_adaptivity.ts
index 3a76473a7882..10741d6ab5a0 100644
--- a/packages/devextreme/js/__internal/grids/grid_core/adaptivity/m_adaptivity.ts
+++ b/packages/devextreme/js/__internal/grids/grid_core/adaptivity/m_adaptivity.ts
@@ -1430,8 +1430,6 @@ export const adaptivityModule: Module = {
   defaultOptions() {
     return {
       columnHidingEnabled: false,
-      // @ts-expect-error
-      onAdaptiveDetailRowPreparing: null as undefined,
     };
   },
   controllers: {
diff --git a/packages/devextreme/js/__internal/grids/grid_core/context_menu/m_context_menu.ts b/packages/devextreme/js/__internal/grids/grid_core/context_menu/m_context_menu.ts
index aadc49ad231c..34e3595ade9e 100644
--- a/packages/devextreme/js/__internal/grids/grid_core/context_menu/m_context_menu.ts
+++ b/packages/devextreme/js/__internal/grids/grid_core/context_menu/m_context_menu.ts
@@ -129,9 +129,7 @@ export class ContextMenuView extends modules.View {
 
 export const contextMenuModule = {
   defaultOptions() {
-    return {
-      onContextMenuPreparing: null,
-    };
+    return {};
   },
   controllers: {
     contextMenu: ContextMenuController,
diff --git a/packages/devextreme/js/__internal/grids/grid_core/data_controller/m_data_controller.ts b/packages/devextreme/js/__internal/grids/grid_core/data_controller/m_data_controller.ts
index c9b720bbf9a0..6259c3bb7edf 100644
--- a/packages/devextreme/js/__internal/grids/grid_core/data_controller/m_data_controller.ts
+++ b/packages/devextreme/js/__internal/grids/grid_core/data_controller/m_data_controller.ts
@@ -1801,11 +1801,10 @@ export const dataControllerModule: Module = {
   defaultOptions() {
     return {
       loadingTimeout: 0,
-      dataSource: null,
+      dataSource: undefined,
       cacheEnabled: true,
       repaintChangesOnly: false,
       highlightChanges: false,
-      onDataErrorOccurred: null as any as undefined,
       remoteOperations: 'auto',
       paging: {
         enabled: true,
diff --git a/packages/devextreme/js/__internal/grids/grid_core/editing/m_editing.ts b/packages/devextreme/js/__internal/grids/grid_core/editing/m_editing.ts
index 6c5bb483c746..a16fe5b928c5 100644
--- a/packages/devextreme/js/__internal/grids/grid_core/editing/m_editing.ts
+++ b/packages/devextreme/js/__internal/grids/grid_core/editing/m_editing.ts
@@ -1168,7 +1168,7 @@ class EditingControllerImpl extends modules.ViewController {
   }
 
   protected _resetEditColumnName() {
-    this._setEditColumnName(null, true);
+    this._setEditColumnName(undefined, true);
   }
 
   protected _getEditColumn() {
@@ -1214,7 +1214,7 @@ class EditingControllerImpl extends modules.ViewController {
 
   protected _resetEditRowKey() {
     this._refocusEditCell = false;
-    this._setEditRowKey(null, true);
+    this._setEditRowKey(undefined, true);
   }
 
   protected _resetEditIndices() {
@@ -2624,7 +2624,7 @@ export const dataControllerEditingExtenderMixin = (Base: ModuleType<DataControll
         (change) => change.type === 'insert' && equalByValue(editRowKey, change.key),
       );
       if (!isEditNewItem && dataSourceKeys.every((key) => !equalByValue(editRowKey, key))) {
-        this.option('editing.editRowKey', null);
+        this.option('editing.editRowKey', undefined);
       }
     }
     return result;
@@ -2939,9 +2939,9 @@ export const editingModule = {
 
         startEditAction: 'click',
 
-        editRowKey: null,
+        editRowKey: undefined,
 
-        editColumnName: null,
+        editColumnName: undefined,
 
         changes: [],
       },
diff --git a/packages/devextreme/js/__internal/grids/grid_core/filter/m_filter_panel.ts b/packages/devextreme/js/__internal/grids/grid_core/filter/m_filter_panel.ts
index 547b31d87734..041e937436d8 100644
--- a/packages/devextreme/js/__internal/grids/grid_core/filter/m_filter_panel.ts
+++ b/packages/devextreme/js/__internal/grids/grid_core/filter/m_filter_panel.ts
@@ -165,7 +165,6 @@ export class FilterPanelView extends modules.View {
 
   private _getRemoveButtonElement() {
     const that = this;
-    // @ts-expect-error
     const clearFilterValue = () => that.option('filterValue', null);
     const clearFilterText = that.option('filterPanel.texts.clearFilter')
       ?? messageLocalization.format('dxDataGrid-filterPanelClearFilter');
diff --git a/packages/devextreme/js/__internal/grids/grid_core/filter/m_filter_sync.ts b/packages/devextreme/js/__internal/grids/grid_core/filter/m_filter_sync.ts
index bf7335f681b7..7dfe13d000f6 100644
--- a/packages/devextreme/js/__internal/grids/grid_core/filter/m_filter_sync.ts
+++ b/packages/devextreme/js/__internal/grids/grid_core/filter/m_filter_sync.ts
@@ -339,12 +339,10 @@ const data = (Base: ModuleType<DataController>) => class DataControllerFilterSyn
     this.component.beginUpdate();
     if (arguments.length > 0) {
       if (filterName === 'filterValue') {
-        // @ts-expect-error
         this.option('filterValue', null);
       }
       super.clearFilter(filterName);
     } else {
-      // @ts-expect-error
       this.option('filterValue', null);
       super.clearFilter();
     }
diff --git a/packages/devextreme/js/__internal/grids/grid_core/state_storing/m_state_storing.ts b/packages/devextreme/js/__internal/grids/grid_core/state_storing/m_state_storing.ts
index 052c59ec6cd2..77a2ac13bca3 100644
--- a/packages/devextreme/js/__internal/grids/grid_core/state_storing/m_state_storing.ts
+++ b/packages/devextreme/js/__internal/grids/grid_core/state_storing/m_state_storing.ts
@@ -287,10 +287,10 @@ export const stateStoringModule = {
     return {
       stateStoring: {
         enabled: false,
-        storageKey: null,
+        storageKey: undefined,
         type: 'localStorage',
-        customLoad: null,
-        customSave: null,
+        customLoad: undefined,
+        customSave: undefined,
         savingTimeout: 2000,
       },
     };
diff --git a/packages/devextreme/js/__internal/grids/tree_list/data_controller/m_data_controller.ts b/packages/devextreme/js/__internal/grids/tree_list/data_controller/m_data_controller.ts
index 5091bd8a65f7..d98f600ba8e1 100644
--- a/packages/devextreme/js/__internal/grids/tree_list/data_controller/m_data_controller.ts
+++ b/packages/devextreme/js/__internal/grids/tree_list/data_controller/m_data_controller.ts
@@ -221,8 +221,6 @@ treeListCore.registerModule('data', {
       filterMode: 'withAncestors',
       expandNodesOnFiltering: true,
       autoExpandAll: false,
-
-      onNodesInitialized: null,
       maxFilterLengthInRequest: 1500,
       paging: {
         enabled: false,
diff --git a/packages/devextreme/js/__internal/m_draggable.ts b/packages/devextreme/js/__internal/m_draggable.ts
index 2d14747b9cc0..7c01f6eeb02a 100644
--- a/packages/devextreme/js/__internal/m_draggable.ts
+++ b/packages/devextreme/js/__internal/m_draggable.ts
@@ -329,17 +329,15 @@ class Draggable extends DOMComponent<Draggable, Properties> {
   _getDefaultOptions(): Properties {
     return {
       ...super._getDefaultOptions(),
+      onDragStart: undefined,
+      onDragMove: undefined,
+      onDragEnd: undefined,
       // @ts-expect-error
-      onDragStart: null,
-      // @ts-expect-error
-      onDragMove: null,
-      // @ts-expect-error
-      onDragEnd: null,
-      onDragEnter: null,
-      onDragLeave: null,
-      onDragCancel: null,
+      onDragEnter: undefined,
+      onDragLeave: undefined,
+      onDragCancel: undefined,
+      onDrop: undefined,
       onCancelByEsc: false,
-      onDrop: null,
       immediate: true,
       dragDirection: 'both',
       boundOffset: 0,
diff --git a/packages/devextreme/js/__internal/m_sortable.ts b/packages/devextreme/js/__internal/m_sortable.ts
index 972d7eb3a5f0..2d5846e5a3f0 100644
--- a/packages/devextreme/js/__internal/m_sortable.ts
+++ b/packages/devextreme/js/__internal/m_sortable.ts
@@ -90,11 +90,11 @@ class Sortable extends Draggable {
       allowDropInsideItem: false,
       allowReordering: true,
       moveItemOnDrop: false,
-      onDragChange: null,
-      onAdd: null,
-      onRemove: null,
-      onReorder: null,
-      onPlaceholderPrepared: null,
+      onDragChange: undefined,
+      onAdd: undefined,
+      onRemove: undefined,
+      onReorder: undefined,
+      onPlaceholderPrepared: undefined,
       placeholderClassName: '',
       animation: {
         type: 'slide',
diff --git a/packages/devextreme/js/common/grids.d.ts b/packages/devextreme/js/common/grids.d.ts
index 5c57e1b09c76..19a85478b545 100644
--- a/packages/devextreme/js/common/grids.d.ts
+++ b/packages/devextreme/js/common/grids.d.ts
@@ -601,7 +601,6 @@ export interface ColumnBase<TRowData = any> {
   falseText?: string;
   /**
    * @docid GridBaseColumn.filterOperations
-   * @default undefined
    * @public
    */
   filterOperations?: Array<FilterOperation | string>;
@@ -620,7 +619,6 @@ export interface ColumnBase<TRowData = any> {
   filterValue?: any | undefined;
   /**
    * @docid GridBaseColumn.filterValues
-   * @default undefined
    * @fires GridBaseOptions.onOptionChanged
    * @public
    */
@@ -1261,18 +1259,18 @@ export interface EditingBase<TRowData = any, TKey = any> {
   changes?: Array<DataChange<TRowData, TKey>>;
   /**
    * @docid GridBaseOptions.editing.editColumnName
-   * @default null
+   * @default undefined
    * @fires GridBaseOptions.onOptionChanged
    * @public
    */
-  editColumnName?: string;
+  editColumnName?: string | undefined;
   /**
    * @docid GridBaseOptions.editing.editRowKey
-   * @default null
+   * @default undefined
    * @fires GridBaseOptions.onOptionChanged
    * @public
    */
-  editRowKey?: TKey;
+  editRowKey?: TKey | undefined;
   /**
    * @docid GridBaseOptions.editing.form
    * @public
@@ -2274,11 +2272,11 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
   columns?: Array<ColumnBase<TRowData> | string> | undefined;
   /**
    * @docid
-   * @default null
+   * @default undefined
    * @public
-   * @type Store|DataSource|DataSourceOptions|string|Array<any>|null
+   * @type Store|DataSource|DataSourceOptions|string|Array<any>|undefined
    */
-  dataSource?: DataSourceLike<TRowData, TKey> | null;
+  dataSource?: DataSourceLike<TRowData, TKey> | undefined;
   /**
    * @docid
    * @public
@@ -2335,7 +2333,7 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @fires GridBase.onOptionChanged
    * @public
    */
-  filterValue?: string | Array<any> | Function;
+  filterValue?: string | Array<any> | Function | null;
   /**
    * @docid
    * @default -1
@@ -2394,7 +2392,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
   noDataText?: string;
   /**
    * @docid
-   * @default null
    * @type_function_param1 e:object
    * @type_function_param1_field component:this
    * @action
@@ -2403,7 +2400,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
   onAIAssistantRequestCreating?: ((e: EventInfo<TComponent> & Cancelable & AIAssistantRequestCreatingInfo) => void);
   /**
    * @docid
-   * @default null
    * @type_function_param1 e:object
    * @type_function_param1_field component:this
    * @type_function_param1_field formOptions:object
@@ -2413,7 +2409,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
   onAdaptiveDetailRowPreparing?: ((e: EventInfo<TComponent> & AdaptiveDetailRowPreparingInfo) => void);
   /**
    * @docid
-   * @default null
    * @type_function_param1 e:object
    * @type_function_param1_field component:this
    * @action
@@ -2425,7 +2420,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1 e:object
    * @type_function_param1_field component:this
    * @type_function_param1_field changes:Array<DataChange>
-   * @default null
    * @action
    * @public
    */
@@ -2435,7 +2429,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1 e:object
    * @type_function_param1_field component:this
    * @type_function_param1_field changes:Array<DataChange>
-   * @default null
    * @action
    * @public
    */
@@ -2446,7 +2439,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1_field component:this
    * @type_function_param1_field data:object
    * @type_function_param1_field promise:Promise<void>
-   * @default null
    * @action
    * @public
    */
@@ -2456,7 +2448,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1 e:object
    * @type_function_param1_field component:this
    * @type_function_param1_field event:event
-   * @default null
    * @action
    * @public
    */
@@ -2466,7 +2457,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1 e:object
    * @type_function_param1_field component:this
    * @type_function_param1_field key:any
-   * @default null
    * @action
    * @public
    */
@@ -2476,7 +2466,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1 e:object
    * @type_function_param1_field component:this
    * @type_function_param1_field key:any
-   * @default null
    * @action
    * @public
    */
@@ -2486,7 +2475,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1 e:object
    * @type_function_param1_field component:this
    * @type_function_param1_field key:any
-   * @default null
    * @action
    * @public
    */
@@ -2496,7 +2484,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1 e:object
    * @type_function_param1_field component:this
    * @type_function_param1_field key:any
-   * @default null
    * @action
    * @public
    */
@@ -2507,7 +2494,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1_field component:this
    * @type_function_param1_field data:object
    * @type_function_param1_field key:any
-   * @default null
    * @action
    * @public
    */
@@ -2518,7 +2504,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1_field component:this
    * @type_function_param1_field data:object
    * @type_function_param1_field cancel:boolean|Promise<void>
-   * @default null
    * @action
    * @public
    */
@@ -2529,7 +2514,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1_field component:this
    * @type_function_param1_field data:object
    * @type_function_param1_field key:any
-   * @default null
    * @action
    * @public
    */
@@ -2541,7 +2525,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1_field data:object
    * @type_function_param1_field key:any
    * @type_function_param1_field cancel:boolean|Promise<void>
-   * @default null
    * @action
    * @public
    */
@@ -2552,7 +2535,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1_field component:this
    * @type_function_param1_field data:object
    * @type_function_param1_field key:any
-   * @default null
    * @action
    * @public
    */
@@ -2565,7 +2547,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1_field newData:object
    * @type_function_param1_field key:any
    * @type_function_param1_field cancel:boolean|Promise<void>
-   * @default null
    * @action
    * @public
    */
@@ -2579,7 +2560,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1_field oldData:object
    * @type_function_param1_field promise:Promise<void>
    * @type_function_param1_field brokenRules:Array<RequiredRule|NumericRule|RangeRule|StringLengthRule|CustomRule|CompareRule|PatternRule|EmailRule|AsyncRule>
-   * @default null
    * @action
    * @public
    */
@@ -2589,7 +2569,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1 e:object
    * @type_function_param1_field component:this
    * @type_function_param1_field changes:Array<DataChange>
-   * @default null
    * @action
    * @public
    */
@@ -2600,7 +2579,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1_field component:this
    * @type_function_param1_field changes:Array<DataChange>
    * @type_function_param1_field promise:Promise<void>
-   * @default null
    * @action
    * @public
    */
@@ -2613,7 +2591,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1_field currentDeselectedRowKeys:Array<any>
    * @type_function_param1_field selectedRowKeys:Array<any>
    * @type_function_param1_field selectedRowsData:Array<Object>
-   * @default null
    * @action
    * @public
    */
@@ -2623,7 +2600,6 @@ export type GridBaseOptions<TComponent extends GridBase<TRowData, TKey>, TRowDat
    * @type_function_param1 e:object
    * @type_function_param1_field component:this
    * @type_function_param1_field toolbarOptions:dxToolbarOptions
-   * @default null
    * @action
    * @public
    */
@@ -3561,9 +3537,9 @@ export type StateStoring = {
   savingTimeout?: number;
   /**
    * @docid GridBaseOptions.stateStoring.storageKey
-   * @default null
+   * @default undefined
    */
-  storageKey?: string;
+  storageKey?: string | undefined;
   /**
    * @docid GridBaseOptions.stateStoring.type
    * @default "localStorage"
diff --git a/packages/devextreme/js/ui/card_view.d.ts b/packages/devextreme/js/ui/card_view.d.ts
index 3e8b9f20f97f..288cf8c6404d 100644
--- a/packages/devextreme/js/ui/card_view.d.ts
+++ b/packages/devextreme/js/ui/card_view.d.ts
@@ -537,37 +537,31 @@ export type HeaderPanel<TCardData = unknown, TKey = unknown> = {
         scrollSensitivity?: number;
         /**
          * @docid
-         * @default null
          * @public
          */
         onDragChange?: ((e: any) => void);
         /**
          * @docid
-         * @default null
          * @public
          */
         onDragEnd?: ((e: any) => void);
         /**
          * @docid
-         * @default null
          * @public
          */
         onDragMove?: ((e: any) => void);
         /**
          * @docid
-         * @default null
          * @public
          */
         onDragStart?: ((e: any) => void);
         /**
          * @docid
-         * @default null
          * @public
          */
         onRemove?: ((e: any) => void);
         /**
          * @docid
-         * @default null
          * @public
          */
         onReorder?: ((e: any) => void);
@@ -1314,10 +1308,10 @@ export interface dxCardViewOptions<TCardData = unknown, TKey = unknown> extends
     /**
      * @docid
      * @default undefined
-     * @type string | Array<any> | Store | DataSource | DataSourceOptions
+     * @type string | Array<any> | Store | DataSource | DataSourceOptions | undefined
      * @public
      */
-    dataSource?: DataSourceLike<TCardData, TKey>;
+    dataSource?: DataSourceLike<TCardData, TKey> | undefined;
     /**
      * @docid
      * @public
@@ -1328,7 +1322,7 @@ export interface dxCardViewOptions<TCardData = unknown, TKey = unknown> extends
      * @default undefined
      * @public
      */
-    keyExpr?: string | string[]; // can be undefined because of default?
+    keyExpr?: string | string[] | undefined;
     /**
      * @docid
      * @default "auto"
@@ -1337,13 +1331,12 @@ export interface dxCardViewOptions<TCardData = unknown, TKey = unknown> extends
     remoteOperations?: RemoteOperations | boolean | Mode;
     /**
      * @docid
-     * @default undefined
      * @type_function_param1 e:object
      * @type_function_param1_field component:this
      * @action
      * @public
      */
-    onDataErrorOccurred?: (e: EventInfo<dxCardView> & DataErrorOccurredInfo) => void;
+    onDataErrorOccurred?: ((e: EventInfo<dxCardView> & DataErrorOccurredInfo) => void);
 
     // #endregion
 
@@ -1592,7 +1585,7 @@ export interface dxCardViewOptions<TCardData = unknown, TKey = unknown> extends
      * @fires dxCardViewOptions.onOptionChanged
      * @public
      */
-    filterValue?: string | Array<any> | Function;
+    filterValue?: string | Array<any> | Function | null;
     /**
      * @docid
      * @public
diff --git a/packages/devextreme/js/ui/data_grid.d.ts b/packages/devextreme/js/ui/data_grid.d.ts
index 9bfd423eb109..fc265e7c3f5a 100644
--- a/packages/devextreme/js/ui/data_grid.d.ts
+++ b/packages/devextreme/js/ui/data_grid.d.ts
@@ -1240,7 +1240,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/data_grid:CellClickEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1248,7 +1247,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/data_grid:CellDblClickEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1256,7 +1254,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/data_grid:CellHoverChangedEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1264,7 +1261,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/data_grid:CellPreparedEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1272,7 +1268,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/data_grid:ContextMenuPreparingEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1280,7 +1275,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/data_grid:EditingStartEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1288,7 +1282,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/data_grid:EditorPreparedEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1296,7 +1289,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/data_grid:EditorPreparingEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1304,7 +1296,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/data_grid:ExportingEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1312,7 +1303,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/data_grid:FocusedCellChangedEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1320,7 +1310,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/data_grid:FocusedCellChangingEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1328,7 +1317,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/data_grid:FocusedRowChangedEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1336,7 +1324,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/data_grid:FocusedRowChangingEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1344,7 +1331,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/data_grid:RowClickEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1352,7 +1338,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/data_grid:RowDblClickEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1360,7 +1345,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/data_grid:RowPreparedEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1465,7 +1449,6 @@ export type dxDataGridOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     toolbar?: Toolbar | undefined;
     /**
      * @docid
-     * @default null
      * @type_function_param1 e:{ui/data_grid:AIColumnRequestCreatingEvent}
      * @action
      * @public
diff --git a/packages/devextreme/js/ui/draggable.d.ts b/packages/devextreme/js/ui/draggable.d.ts
index b07df893d6e7..cd07a46d31ae 100644
--- a/packages/devextreme/js/ui/draggable.d.ts
+++ b/packages/devextreme/js/ui/draggable.d.ts
@@ -219,28 +219,28 @@ export interface dxDraggableOptions extends DraggableBaseOptions<dxDraggable> {
     dragTemplate?: template | ((dragInfo: DragTemplateData, containerElement: DxElement) => string | UserDefinedElement) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/draggable:DragEndEvent}
      * @action
      * @public
      */
-    onDragEnd?: ((e: DragEndEvent) => void);
+    onDragEnd?: ((e: DragEndEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/draggable:DragMoveEvent}
      * @action
      * @public
      */
-    onDragMove?: ((e: DragMoveEvent) => void);
+    onDragMove?: ((e: DragMoveEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/draggable:DragStartEvent}
      * @action
      * @public
      */
-    onDragStart?: ((e: DragStartEvent) => void);
+    onDragStart?: ((e: DragStartEvent) => void) | undefined;
 }
 /**
  * @docid
diff --git a/packages/devextreme/js/ui/filter_builder.d.ts b/packages/devextreme/js/ui/filter_builder.d.ts
index 579c62cbb29b..85c012d4e3f7 100644
--- a/packages/devextreme/js/ui/filter_builder.d.ts
+++ b/packages/devextreme/js/ui/filter_builder.d.ts
@@ -307,27 +307,27 @@ export interface dxFilterBuilderOptions extends WidgetOptions<dxFilterBuilder> {
     /**
      * @docid
      * @type_function_param1 e:{ui/filter_builder:EditorPreparedEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onEditorPrepared?: ((e: EditorPreparedEvent) => void);
+    onEditorPrepared?: ((e: EditorPreparedEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/filter_builder:EditorPreparingEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onEditorPreparing?: ((e: EditorPreparingEvent) => void);
+    onEditorPreparing?: ((e: EditorPreparingEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/filter_builder:ValueChangedEvent}
      * @action
      * @public
      */
-    onValueChanged?: ((e: ValueChangedEvent) => void);
+    onValueChanged?: ((e: ValueChangedEvent) => void) | undefined;
     /**
      * @docid
      * @type Filter expression
@@ -335,7 +335,7 @@ export interface dxFilterBuilderOptions extends WidgetOptions<dxFilterBuilder> {
      * @fires dxFilterBuilderOptions.onValueChanged
      * @public
      */
-    value?: string | Array<any> | Function;
+    value?: string | Array<any> | Function | null;
 }
 /**
  * @docid
@@ -503,7 +503,6 @@ export interface dxFilterBuilderField {
     falseText?: string;
     /**
      * @docid
-     * @default undefined
      * @public
      */
     filterOperations?: Array<FilterBuilderOperation | string>;
@@ -515,7 +514,6 @@ export interface dxFilterBuilderField {
     format?: Format;
     /**
      * @docid
-     * @default undefined
      * @public
      */
     lookup?: {
diff --git a/packages/devextreme/js/ui/sortable.d.ts b/packages/devextreme/js/ui/sortable.d.ts
index b66982894236..e3feaedd0c5f 100644
--- a/packages/devextreme/js/ui/sortable.d.ts
+++ b/packages/devextreme/js/ui/sortable.d.ts
@@ -309,60 +309,60 @@ export interface dxSortableOptions extends DraggableBaseOptions<dxSortable> {
     moveItemOnDrop?: boolean;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/sortable:AddEvent}
      * @action
      * @public
      */
-    onAdd?: ((e: AddEvent) => void);
+    onAdd?: ((e: AddEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/sortable:DragChangeEvent}
      * @action
      * @public
      */
-    onDragChange?: ((e: DragChangeEvent) => void);
+    onDragChange?: ((e: DragChangeEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/sortable:DragEndEvent}
      * @action
      * @public
      */
-    onDragEnd?: ((e: DragEndEvent) => void);
+    onDragEnd?: ((e: DragEndEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/sortable:DragMoveEvent}
      * @action
      * @public
      */
-    onDragMove?: ((e: DragMoveEvent) => void);
+    onDragMove?: ((e: DragMoveEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/sortable:DragStartEvent}
      * @action
      * @public
      */
-    onDragStart?: ((e: DragStartEvent) => void);
+    onDragStart?: ((e: DragStartEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/sortable:RemoveEvent}
      * @action
      * @public
      */
-    onRemove?: ((e: RemoveEvent) => void);
+    onRemove?: ((e: RemoveEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/sortable:ReorderEvent}
      * @action
      * @public
      */
-    onReorder?: ((e: ReorderEvent) => void);
+    onReorder?: ((e: ReorderEvent) => void) | undefined;
 }
 /**
  * @docid
diff --git a/packages/devextreme/js/ui/tree_list.d.ts b/packages/devextreme/js/ui/tree_list.d.ts
index 207d2db69718..96daa6bac6ca 100644
--- a/packages/devextreme/js/ui/tree_list.d.ts
+++ b/packages/devextreme/js/ui/tree_list.d.ts
@@ -997,7 +997,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:CellClickEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1005,7 +1004,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:CellDblClickEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1013,7 +1011,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:CellHoverChangedEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1021,7 +1018,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:CellPreparedEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1029,7 +1025,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:ContextMenuPreparingEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1037,7 +1032,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:EditingStartEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1045,7 +1039,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:EditorPreparedEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1053,7 +1046,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:EditorPreparingEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1061,7 +1053,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:FocusedCellChangedEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1069,7 +1060,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:FocusedCellChangingEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1077,7 +1067,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:FocusedRowChangedEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1085,7 +1074,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:FocusedRowChangingEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1093,7 +1081,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:NodesInitializedEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1101,7 +1088,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:RowClickEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1109,7 +1095,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:RowDblClickEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1117,7 +1102,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     /**
      * @docid
      * @type_function_param1 e:{ui/tree_list:RowPreparedEvent}
-     * @default null
      * @action
      * @public
      */
@@ -1183,7 +1167,6 @@ export type dxTreeListOptions<TRowData = any, TKey = any> = Omit<GridBaseOptions
     toolbar?: Toolbar | undefined;
     /**
      * @docid
-     * @default null
      * @type_function_param1 e:{ui/tree_list:AIColumnRequestCreatingEvent}
      * @action
      * @public
diff --git a/packages/devextreme/testing/tests/DevExpress.ui.widgets.dataGrid/editing.integration.tests.js b/packages/devextreme/testing/tests/DevExpress.ui.widgets.dataGrid/editing.integration.tests.js
index b2cd2e555d08..8949d47315b5 100644
--- a/packages/devextreme/testing/tests/DevExpress.ui.widgets.dataGrid/editing.integration.tests.js
+++ b/packages/devextreme/testing/tests/DevExpress.ui.widgets.dataGrid/editing.integration.tests.js
@@ -7203,7 +7203,7 @@ QUnit.module('Editing state', baseModuleConfig, () => {
 
         // assert
         assert.deepEqual(dataGrid.option('editing.changes'), [], 'change are empty');
-        assert.deepEqual(dataGrid.option('editing.editRowKey'), null, 'editRowKey is empty');
+        assert.deepEqual(dataGrid.option('editing.editRowKey'), undefined, 'editRowKey is empty');
     });
 
 
diff --git a/packages/devextreme/ts/dx.all.d.ts b/packages/devextreme/ts/dx.all.d.ts
index e5da1ca7358d..d915f281adee 100644
--- a/packages/devextreme/ts/dx.all.d.ts
+++ b/packages/devextreme/ts/dx.all.d.ts
@@ -5368,11 +5368,11 @@ declare module DevExpress.common.grids {
     /**
      * [descr:GridBaseOptions.editing.editColumnName]
      */
-    editColumnName?: string;
+    editColumnName?: string | undefined;
     /**
      * [descr:GridBaseOptions.editing.editRowKey]
      */
-    editRowKey?: TKey;
+    editRowKey?: TKey | undefined;
     /**
      * [descr:GridBaseOptions.editing.form]
      */
@@ -6012,7 +6012,7 @@ declare module DevExpress.common.grids {
     /**
      * [descr:GridBaseOptions.dataSource]
      */
-    dataSource?: DevExpress.data.DataSourceLike<TRowData, TKey> | null;
+    dataSource?: DevExpress.data.DataSourceLike<TRowData, TKey> | undefined;
     /**
      * [descr:GridBaseOptions.dateSerializationFormat]
      */
@@ -6048,7 +6048,7 @@ declare module DevExpress.common.grids {
     /**
      * [descr:GridBaseOptions.filterValue]
      */
-    filterValue?: string | Array<any> | Function;
+    filterValue?: string | Array<any> | Function | null;
     /**
      * [descr:GridBaseOptions.focusedColumnIndex]
      */
@@ -7168,7 +7168,7 @@ declare module DevExpress.common.grids {
     /**
      * [descr:GridBaseOptions.stateStoring.storageKey]
      */
-    storageKey?: string;
+    storageKey?: string | undefined;
     /**
      * [descr:GridBaseOptions.stateStoring.type]
      */
@@ -11138,7 +11138,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxCardViewOptions.dataSource]
      */
-    dataSource?: DevExpress.data.DataSourceLike<TCardData, TKey>;
+    dataSource?: DevExpress.data.DataSourceLike<TCardData, TKey> | undefined;
     /**
      * [descr:dxCardViewOptions.paging]
      */
@@ -11146,7 +11146,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxCardViewOptions.keyExpr]
      */
-    keyExpr?: string | string[];
+    keyExpr?: string | string[] | undefined;
     /**
      * [descr:dxCardViewOptions.remoteOperations]
      */
@@ -11355,7 +11355,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxCardViewOptions.filterValue]
      */
-    filterValue?: string | Array<any> | Function;
+    filterValue?: string | Array<any> | Function | null;
     /**
      * [descr:dxCardViewOptions.filterBuilderPopup]
      */
@@ -16659,15 +16659,21 @@ declare module DevExpress.ui {
     /**
      * [descr:dxDraggableOptions.onDragEnd]
      */
-    onDragEnd?: (e: DevExpress.ui.dxDraggable.DragEndEvent) => void;
+    onDragEnd?:
+      | ((e: DevExpress.ui.dxDraggable.DragEndEvent) => void)
+      | undefined;
     /**
      * [descr:dxDraggableOptions.onDragMove]
      */
-    onDragMove?: (e: DevExpress.ui.dxDraggable.DragMoveEvent) => void;
+    onDragMove?:
+      | ((e: DevExpress.ui.dxDraggable.DragMoveEvent) => void)
+      | undefined;
     /**
      * [descr:dxDraggableOptions.onDragStart]
      */
-    onDragStart?: (e: DevExpress.ui.dxDraggable.DragStartEvent) => void;
+    onDragStart?:
+      | ((e: DevExpress.ui.dxDraggable.DragStartEvent) => void)
+      | undefined;
   }
   /**
    * [descr:dxDrawer]
@@ -19162,25 +19168,25 @@ declare module DevExpress.ui {
     /**
      * [descr:dxFilterBuilderOptions.onEditorPrepared]
      */
-    onEditorPrepared?: (
-      e: DevExpress.ui.dxFilterBuilder.EditorPreparedEvent
-    ) => void;
+    onEditorPrepared?:
+      | ((e: DevExpress.ui.dxFilterBuilder.EditorPreparedEvent) => void)
+      | undefined;
     /**
      * [descr:dxFilterBuilderOptions.onEditorPreparing]
      */
-    onEditorPreparing?: (
-      e: DevExpress.ui.dxFilterBuilder.EditorPreparingEvent
-    ) => void;
+    onEditorPreparing?:
+      | ((e: DevExpress.ui.dxFilterBuilder.EditorPreparingEvent) => void)
+      | undefined;
     /**
      * [descr:dxFilterBuilderOptions.onValueChanged]
      */
-    onValueChanged?: (
-      e: DevExpress.ui.dxFilterBuilder.ValueChangedEvent
-    ) => void;
+    onValueChanged?:
+      | ((e: DevExpress.ui.dxFilterBuilder.ValueChangedEvent) => void)
+      | undefined;
     /**
      * [descr:dxFilterBuilderOptions.value]
      */
-    value?: string | Array<any> | Function;
+    value?: string | Array<any> | Function | null;
   }
   /**
    * [descr:dxForm]
@@ -28388,31 +28394,41 @@ declare module DevExpress.ui {
     /**
      * [descr:dxSortableOptions.onAdd]
      */
-    onAdd?: (e: DevExpress.ui.dxSortable.AddEvent) => void;
+    onAdd?: ((e: DevExpress.ui.dxSortable.AddEvent) => void) | undefined;
     /**
      * [descr:dxSortableOptions.onDragChange]
      */
-    onDragChange?: (e: DevExpress.ui.dxSortable.DragChangeEvent) => void;
+    onDragChange?:
+      | ((e: DevExpress.ui.dxSortable.DragChangeEvent) => void)
+      | undefined;
     /**
      * [descr:dxSortableOptions.onDragEnd]
      */
-    onDragEnd?: (e: DevExpress.ui.dxSortable.DragEndEvent) => void;
+    onDragEnd?:
+      | ((e: DevExpress.ui.dxSortable.DragEndEvent) => void)
+      | undefined;
     /**
      * [descr:dxSortableOptions.onDragMove]
      */
-    onDragMove?: (e: DevExpress.ui.dxSortable.DragMoveEvent) => void;
+    onDragMove?:
+      | ((e: DevExpress.ui.dxSortable.DragMoveEvent) => void)
+      | undefined;
     /**
      * [descr:dxSortableOptions.onDragStart]
      */
-    onDragStart?: (e: DevExpress.ui.dxSortable.DragStartEvent) => void;
+    onDragStart?:
+      | ((e: DevExpress.ui.dxSortable.DragStartEvent) => void)
+      | undefined;
     /**
      * [descr:dxSortableOptions.onRemove]
      */
-    onRemove?: (e: DevExpress.ui.dxSortable.RemoveEvent) => void;
+    onRemove?: ((e: DevExpress.ui.dxSortable.RemoveEvent) => void) | undefined;
     /**
      * [descr:dxSortableOptions.onReorder]
      */
-    onReorder?: (e: DevExpress.ui.dxSortable.ReorderEvent) => void;
+    onReorder?:
+      | ((e: DevExpress.ui.dxSortable.ReorderEvent) => void)
+      | undefined;
   }
   /**
    * [descr:dxSpeechToText]