diff --git a/packages/devextreme/js/__internal/core/m_class.ts b/packages/devextreme/js/__internal/core/m_class.ts
index d6717599258..6f5efe98a97 100644
--- a/packages/devextreme/js/__internal/core/m_class.ts
+++ b/packages/devextreme/js/__internal/core/m_class.ts
@@ -40,6 +40,7 @@ const redefine = function (members) {
 };
 
 const include = function (...args) {
+  debugger;
   const classObj = this;
   let argument;
   let name;
diff --git a/packages/devextreme/js/__internal/data/m_data_helper.ts b/packages/devextreme/js/__internal/data/m_data_helper.ts
index 255fce44846..b9499ff9641 100644
--- a/packages/devextreme/js/__internal/data/m_data_helper.ts
+++ b/packages/devextreme/js/__internal/data/m_data_helper.ts
@@ -1,8 +1,7 @@
-
-import { DataSource } from '../../common/data/data_source/data_source';
-import { extend } from '../../core/utils/extend';
-import { normalizeDataSourceOptions } from '../../common/data/data_source/utils';
-import DataController from '../ui/collection/m_data_controller';
+import { DataSource } from '@js/common/data/data_source/data_source';
+import { normalizeDataSourceOptions } from '@js/common/data/data_source/utils';
+import { extend } from '@js/core/utils/extend';
+import DataController from '@ts/ui/collection/m_data_controller';
 
 const DATA_SOURCE_OPTIONS_METHOD = '_dataSourceOptions';
 const DATA_SOURCE_CHANGED_METHOD = '_dataSourceChangedHandler';
@@ -12,155 +11,159 @@ const DATA_SOURCE_FROM_URL_LOAD_MODE_METHOD = '_dataSourceFromUrlLoadMode';
 const SPECIFIC_DATA_SOURCE_OPTION = '_getSpecificDataSourceOption';
 const NORMALIZE_DATA_SOURCE = '_normalizeDataSource';
 
+export const DataHelperMixin = {
+  postCtor(): void {
+    this.on('disposing', () => {
+      this._disposeDataSource();
+    });
+  },
+
+  _refreshDataSource(): void {
+    this._initDataSource();
+    this._loadDataSource();
+  },
+
+  _initDataSource(): void {
+    let dataSourceOptions = SPECIFIC_DATA_SOURCE_OPTION in this
+      ? this[SPECIFIC_DATA_SOURCE_OPTION]()
+      : this.option('dataSource');
+
+    let widgetDataSourceOptions;
+    let dataSourceType;
+
+    this._disposeDataSource();
+
+    if (dataSourceOptions) {
+      if (dataSourceOptions instanceof DataSource) {
+        this._isSharedDataSource = true;
+        this._dataSource = dataSourceOptions;
+      } else {
+        widgetDataSourceOptions = DATA_SOURCE_OPTIONS_METHOD in this
+          ? this[DATA_SOURCE_OPTIONS_METHOD]()
+          : {};
+
+        dataSourceType = this._dataSourceType ? this._dataSourceType() : DataSource;
+
+        dataSourceOptions = normalizeDataSourceOptions(dataSourceOptions, {
+          fromUrlLoadMode: (DATA_SOURCE_FROM_URL_LOAD_MODE_METHOD in this) && this[DATA_SOURCE_FROM_URL_LOAD_MODE_METHOD](),
+        });
+
+        // eslint-disable-next-line new-cap
+        this._dataSource = new dataSourceType(extend(true, {}, widgetDataSourceOptions, dataSourceOptions));
+      }
+
+      if (NORMALIZE_DATA_SOURCE in this) {
+        this._dataSource = this[NORMALIZE_DATA_SOURCE](this._dataSource);
+      }
+
+      this._addDataSourceHandlers();
+      this._initDataController();
+    }
+  },
 
-const DataHelperMixin = {
-
-    postCtor: function() {
-        this.on('disposing', function() {
-            this._disposeDataSource();
-        }.bind(this));
-    },
-
-    _refreshDataSource: function() {
-        this._initDataSource();
-        this._loadDataSource();
-    },
-
-    _initDataSource: function() {
-        let dataSourceOptions = (SPECIFIC_DATA_SOURCE_OPTION in this) ? this[SPECIFIC_DATA_SOURCE_OPTION]() : this.option('dataSource');
-        let widgetDataSourceOptions;
-        let dataSourceType;
+  _initDataController(): void {
+    const dataController = this.option?.('_dataController');
+    const dataSource = this._dataSource;
 
-        this._disposeDataSource();
+    if (dataController) {
+      this._dataController = dataController;
+    } else {
+      this._dataController = new DataController(dataSource);
+    }
+  },
 
-        if(dataSourceOptions) {
-            if(dataSourceOptions instanceof DataSource) {
-                this._isSharedDataSource = true;
-                this._dataSource = dataSourceOptions;
-            } else {
-                widgetDataSourceOptions = (DATA_SOURCE_OPTIONS_METHOD in this) ? this[DATA_SOURCE_OPTIONS_METHOD]() : {};
-                dataSourceType = this._dataSourceType ? this._dataSourceType() : DataSource;
+  _addDataSourceHandlers(): void {
+    if (DATA_SOURCE_CHANGED_METHOD in this) {
+      this._addDataSourceChangeHandler();
+    }
 
-                dataSourceOptions = normalizeDataSourceOptions(dataSourceOptions, {
-                    fromUrlLoadMode: (DATA_SOURCE_FROM_URL_LOAD_MODE_METHOD in this) && this[DATA_SOURCE_FROM_URL_LOAD_MODE_METHOD]()
-                });
+    if (DATA_SOURCE_LOAD_ERROR_METHOD in this) {
+      this._addDataSourceLoadErrorHandler();
+    }
 
-                this._dataSource = new dataSourceType(extend(true, {}, widgetDataSourceOptions, dataSourceOptions));
-            }
+    if (DATA_SOURCE_LOADING_CHANGED_METHOD in this) {
+      this._addDataSourceLoadingChangedHandler();
+    }
 
-            if(NORMALIZE_DATA_SOURCE in this) {
-                this._dataSource = this[NORMALIZE_DATA_SOURCE](this._dataSource);
-            }
+    this._addReadyWatcher();
+  },
+
+  _addReadyWatcher(): void {
+    this.readyWatcher = function (isLoading) {
+      this._ready && this._ready(!isLoading);
+    }.bind(this);
+    this._dataSource.on('loadingChanged', this.readyWatcher);
+  },
+
+  _addDataSourceChangeHandler(): void {
+    const dataSource = this._dataSource;
+    this._proxiedDataSourceChangedHandler = function (e) {
+      this[DATA_SOURCE_CHANGED_METHOD](dataSource.items(), e);
+    }.bind(this);
+    dataSource.on('changed', this._proxiedDataSourceChangedHandler);
+  },
+
+  _addDataSourceLoadErrorHandler(): void {
+    this._proxiedDataSourceLoadErrorHandler = this[DATA_SOURCE_LOAD_ERROR_METHOD].bind(this);
+    this._dataSource.on('loadError', this._proxiedDataSourceLoadErrorHandler);
+  },
+
+  _addDataSourceLoadingChangedHandler(): void {
+    this._proxiedDataSourceLoadingChangedHandler = this[DATA_SOURCE_LOADING_CHANGED_METHOD].bind(this);
+    this._dataSource.on('loadingChanged', this._proxiedDataSourceLoadingChangedHandler);
+  },
+
+  _loadDataSource(): void {
+    const dataSource = this._dataSource;
+    if (dataSource) {
+      if (dataSource.isLoaded()) {
+        this._proxiedDataSourceChangedHandler && this._proxiedDataSourceChangedHandler();
+      } else {
+        dataSource.load();
+      }
+    }
+  },
 
-            this._addDataSourceHandlers();
-            this._initDataController();
-        }
-    },
+  _loadSingle(key, value) {
+    key = key === 'this' ? this._dataSource.key() || 'this' : key;
+    return this._dataSource.loadSingle(key, value);
+  },
 
-    _initDataController: function() {
-        const dataController = this.option?.('_dataController');
-        const dataSource = this._dataSource;
+  _isLastPage(): boolean {
+    return !this._dataSource || this._dataSource.isLastPage() || !this._dataSource._pageSize;
+  },
 
-        if(dataController) {
-            this._dataController = dataController;
-        } else {
-            this._dataController = new DataController(dataSource);
-        }
-    },
+  _isDataSourceLoading() {
+    return this._dataSource && this._dataSource.isLoading();
+  },
 
-    _addDataSourceHandlers: function() {
-        if(DATA_SOURCE_CHANGED_METHOD in this) {
-            this._addDataSourceChangeHandler();
-        }
+  _disposeDataSource(): void {
+    if (this._dataSource) {
+      if (this._isSharedDataSource) {
+        delete this._isSharedDataSource;
 
-        if(DATA_SOURCE_LOAD_ERROR_METHOD in this) {
-            this._addDataSourceLoadErrorHandler();
-        }
+        this._proxiedDataSourceChangedHandler && this._dataSource.off('changed', this._proxiedDataSourceChangedHandler);
+        this._proxiedDataSourceLoadErrorHandler && this._dataSource.off('loadError', this._proxiedDataSourceLoadErrorHandler);
+        this._proxiedDataSourceLoadingChangedHandler && this._dataSource.off('loadingChanged', this._proxiedDataSourceLoadingChangedHandler);
 
-        if(DATA_SOURCE_LOADING_CHANGED_METHOD in this) {
-            this._addDataSourceLoadingChangedHandler();
+        if (this._dataSource._eventsStrategy) {
+          this._dataSource._eventsStrategy.off('loadingChanged', this.readyWatcher);
         }
+      } else {
+        this._dataSource.dispose();
+      }
 
-        this._addReadyWatcher();
-    },
-
-    _addReadyWatcher: function() {
-        this.readyWatcher = (function(isLoading) {
-            this._ready && this._ready(!isLoading);
-        }).bind(this);
-        this._dataSource.on('loadingChanged', this.readyWatcher);
-    },
-
-    _addDataSourceChangeHandler: function() {
-        const dataSource = this._dataSource;
-        this._proxiedDataSourceChangedHandler = (function(e) {
-            this[DATA_SOURCE_CHANGED_METHOD](dataSource.items(), e);
-        }).bind(this);
-        dataSource.on('changed', this._proxiedDataSourceChangedHandler);
-    },
-
-    _addDataSourceLoadErrorHandler: function() {
-        this._proxiedDataSourceLoadErrorHandler = this[DATA_SOURCE_LOAD_ERROR_METHOD].bind(this);
-        this._dataSource.on('loadError', this._proxiedDataSourceLoadErrorHandler);
-    },
-
-    _addDataSourceLoadingChangedHandler: function() {
-        this._proxiedDataSourceLoadingChangedHandler = this[DATA_SOURCE_LOADING_CHANGED_METHOD].bind(this);
-        this._dataSource.on('loadingChanged', this._proxiedDataSourceLoadingChangedHandler);
-    },
-
-    _loadDataSource: function() {
-        const dataSource = this._dataSource;
-        if(dataSource) {
-            if(dataSource.isLoaded()) {
-                this._proxiedDataSourceChangedHandler && this._proxiedDataSourceChangedHandler();
-            } else {
-                dataSource.load();
-            }
-        }
-    },
-
-    _loadSingle: function(key, value) {
-        key = key === 'this' ? this._dataSource.key() || 'this' : key;
-        return this._dataSource.loadSingle(key, value);
-    },
-
-    _isLastPage: function() {
-        return !this._dataSource || this._dataSource.isLastPage() || !this._dataSource._pageSize;
-    },
-
-    _isDataSourceLoading: function() {
-        return this._dataSource && this._dataSource.isLoading();
-    },
-
-    _disposeDataSource: function() {
-        if(this._dataSource) {
-            if(this._isSharedDataSource) {
-                delete this._isSharedDataSource;
-
-                this._proxiedDataSourceChangedHandler && this._dataSource.off('changed', this._proxiedDataSourceChangedHandler);
-                this._proxiedDataSourceLoadErrorHandler && this._dataSource.off('loadError', this._proxiedDataSourceLoadErrorHandler);
-                this._proxiedDataSourceLoadingChangedHandler && this._dataSource.off('loadingChanged', this._proxiedDataSourceLoadingChangedHandler);
-
-                if(this._dataSource._eventsStrategy) {
-                    this._dataSource._eventsStrategy.off('loadingChanged', this.readyWatcher);
-                }
-            } else {
-                this._dataSource.dispose();
-            }
-
-            delete this._dataSource;
-
-            delete this._proxiedDataSourceChangedHandler;
-            delete this._proxiedDataSourceLoadErrorHandler;
-            delete this._proxiedDataSourceLoadingChangedHandler;
-        }
-    },
+      delete this._dataSource;
 
-    getDataSource: function() {
-        return this._dataSource || null;
+      delete this._proxiedDataSourceChangedHandler;
+      delete this._proxiedDataSourceLoadErrorHandler;
+      delete this._proxiedDataSourceLoadingChangedHandler;
     }
+  },
 
+  getDataSource() {
+    return this._dataSource || null;
+  },
 };
 
 export default DataHelperMixin;
diff --git a/packages/devextreme/js/__internal/scheduler/m_scheduler.ts b/packages/devextreme/js/__internal/scheduler/m_scheduler.ts
index f4a4354f5e7..b07f185b3f0 100644
--- a/packages/devextreme/js/__internal/scheduler/m_scheduler.ts
+++ b/packages/devextreme/js/__internal/scheduler/m_scheduler.ts
@@ -1,7 +1,6 @@
 import { triggerResizeEvent } from '@js/common/core/events/visibility_change';
 import dateLocalization from '@js/common/core/localization/date';
 import messageLocalization from '@js/common/core/localization/message';
-import DataHelperMixin from '@ts/data/m_data_helper';
 import registerComponent from '@js/core/component_registrator';
 import config from '@js/core/config';
 import devices from '@js/core/devices';
@@ -30,6 +29,7 @@ import {
   isString,
 } from '@js/core/utils/type';
 import { hasWindow } from '@js/core/utils/window';
+import DataHelperMixin from '@js/data_helper';
 import { custom as customDialog } from '@js/ui/dialog';
 import type { AppointmentTooltipShowingEvent, ViewType } from '@js/ui/scheduler';
 import { isMaterial, isMaterialBased } from '@js/ui/themes';
diff --git a/packages/devextreme/js/__internal/ui/chat/chat.ts b/packages/devextreme/js/__internal/ui/chat/chat.ts
index 4308d907628..fa9b0b4f20b 100644
--- a/packages/devextreme/js/__internal/ui/chat/chat.ts
+++ b/packages/devextreme/js/__internal/ui/chat/chat.ts
@@ -1,11 +1,11 @@
 import { Guid } from '@js/common';
 import messageLocalization from '@js/common/core/localization/message';
 import type { DataSourceOptions } from '@js/common/data';
-import DataHelperMixin from '@ts/data/m_data_helper';
 import registerComponent from '@js/core/component_registrator';
 import type { dxElementWrapper } from '@js/core/renderer';
 import $ from '@js/core/renderer';
 import { isDefined } from '@js/core/utils/type';
+import DataHelperMixin from '@js/data_helper';
 import type {
   Message,
   MessageEnteredEvent,
diff --git a/packages/devextreme/js/__internal/ui/collection/collection_widget.base.ts b/packages/devextreme/js/__internal/ui/collection/collection_widget.base.ts
index 224a297208b..e3893da4f76 100644
--- a/packages/devextreme/js/__internal/ui/collection/collection_widget.base.ts
+++ b/packages/devextreme/js/__internal/ui/collection/collection_widget.base.ts
@@ -26,6 +26,7 @@ import { getOuterHeight, getOuterWidth } from '@js/core/utils/size';
 import { findTemplates } from '@js/core/utils/template_manager';
 import { isDefined, isFunction, isPlainObject } from '@js/core/utils/type';
 import type { DataSourceOptions } from '@js/data/data_source';
+import DataHelperMixin from '@js/data_helper';
 import type {
   Cancelable, DxEvent, EventInfo, ItemInfo,
 } from '@js/events';
@@ -34,7 +35,6 @@ import { focusable } from '@js/ui/widget/selectors';
 import { getPublicElement } from '@ts/core/m_element';
 import type { OptionChanged } from '@ts/core/widget/types';
 import Widget from '@ts/core/widget/widget';
-import DataHelperMixin from '@ts/data/m_data_helper';
 import CollectionWidgetItem from '@ts/ui/collection/m_item';
 
 const COLLECTION_CLASS = 'dx-collection';
diff --git a/packages/devextreme/js/__internal/ui/editor/m_data_expression.ts b/packages/devextreme/js/__internal/ui/editor/m_data_expression.ts
index 8e84dc2aed5..369fb532d86 100644
--- a/packages/devextreme/js/__internal/ui/editor/m_data_expression.ts
+++ b/packages/devextreme/js/__internal/ui/editor/m_data_expression.ts
@@ -1,5 +1,4 @@
 import ArrayStore from '@js/common/data/array_store';
-import DataHelperMixin from '@ts/data/m_data_helper';
 import DataSource from '@js/common/data/data_source';
 import { ensureDefined, noop } from '@js/core/utils/common';
 import {
@@ -12,6 +11,7 @@ import {
   isDefined, isFunction, isObject as isObjectType, isString,
 } from '@js/core/utils/type';
 import variableWrapper from '@js/core/utils/variable_wrapper';
+import DataHelperMixin from '@js/data_helper';
 
 const DataExpressionMixin = extend({}, DataHelperMixin, {
 
diff --git a/packages/devextreme/js/data_helper.js b/packages/devextreme/js/data_helper.js
index 6af09beb52c..c571549071c 100644
--- a/packages/devextreme/js/data_helper.js
+++ b/packages/devextreme/js/data_helper.js
@@ -1,3 +1,3 @@
-import { DataHelperMixin } from './common/data';
+import { DataHelperMixin } from './__internal/data/m_data_helper';
 
 export default DataHelperMixin;
diff --git a/packages/devextreme/js/viz/core/data_source.js b/packages/devextreme/js/viz/core/data_source.js
index c7a4b6d2be4..5f33a3c1ee9 100644
--- a/packages/devextreme/js/viz/core/data_source.js
+++ b/packages/devextreme/js/viz/core/data_source.js
@@ -1,5 +1,5 @@
 import { noop } from '../../core/utils/common';
-import DataHelperMixin from '../../__internal/data/m_data_helper';
+import DataHelperMixin from '../../data_helper';
 const postCtor = DataHelperMixin.postCtor;
 let name;
 const members = {