GridCore data: Remove `DataSourceAdapter` dynamic member-copy and type `_dataSource` by bit-byte0 · Pull Request #34980 · DevExpress/DevExtreme

bit-byte0 · 2026-08-29T16:53:20Z

What

Removes the runtime block in DataSourceAdapter that dynamically copied every DataSource method onto the adapter, and types DataController._dataSource as DataSourceAdapter instead of any

How

Replaced the dynamic copy with explicit typed delegates on the adapter, promoted the adapter's consumed methods to public, and narrowed _dataSource to the concrete adapter subtype in the virtual scrolling and tree_list extenders where subclass methods are used

…t delegates

…atacontroller-type-datasource-adapter-26_2 # Conflicts: # packages/devextreme/js/__internal/grids/data_grid/grouping/m_grouping.ts

…in de-proxy

…urce for unconditional delegates

Copilot

Pull request overview

This PR removes DataSourceAdapter’s runtime “copy every DataSource method onto the adapter” behavior and replaces it with explicitly declared, typed delegating methods, while narrowing DataController._dataSource from any to DataSourceAdapter | null and adding more specific _dataSource typings in TreeList/virtual scrolling extenders.

Changes:

Replaced dynamic member-copying in DataSourceAdapter with explicit delegating methods (and promoted several adapter methods to public).
Narrowed DataController._dataSource typing and updated downstream grid/tree-list modules to accommodate the stricter type surface.
Updated test mocks to provide newly required DataSource methods.

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
packages/devextreme/testing/helpers/gridBaseMocks.js	Extends mock DataSource shape to satisfy new adapter delegates.
packages/devextreme/js/__internal/grids/tree_list/m_virtual_scrolling.ts	Adjusts TreeList virtual scrolling controller/adapter visibility and access patterns.
packages/devextreme/js/__internal/grids/tree_list/m_focus.ts	Adds TreeList-specific adapter typing and additional casts for stricter `_dataSource` typing.
packages/devextreme/js/__internal/grids/tree_list/data_source_adapter/m_data_source_adapter.ts	Promotes various TreeList adapter methods to `public` for external use.
packages/devextreme/js/__internal/grids/tree_list/data_controller/m_data_controller.ts	Narrows TreeList `_dataSource` typing and adjusts calls for stricter types.
packages/devextreme/js/__internal/grids/grid_core/virtual_scrolling/m_virtual_scrolling.ts	Promotes virtual scrolling adapter methods to `public` for typed access.
packages/devextreme/js/__internal/grids/grid_core/virtual_scrolling/extenders/virtual_scrolling_data_controller.ts	Adds a concrete virtual-scrolling adapter instance type for `_dataSource`.
packages/devextreme/js/__internal/grids/grid_core/focus/m_focus.ts	Updates focus logic to use stricter `_dataSource` typing/non-null assertions.
packages/devextreme/js/__internal/grids/grid_core/data_source_adapter/m_data_source_adapter.ts	Removes dynamic method copying; introduces explicit delegates and makes several members `public`.
packages/devextreme/js/__internal/grids/grid_core/data_controller/data_controller.ts	Types `_dataSource` as `DataSourceAdapter
packages/devextreme/js/__internal/grids/data_grid/summary/extenders/summary_data_controller.ts	Casts `_dataSource` for access to DataGrid-only aggregates API under stricter typing.
packages/devextreme/js/__internal/grids/data_grid/grouping/m_grouping.ts	Promotes grouping adapter methods to `public` to match new adapter surface.
packages/devextreme/js/__internal/grids/data_grid/grouping/extenders/grouping_data_controller.ts	Casts `_dataSource` to access grouping-only adapter APIs.
packages/devextreme/js/__internal/grids/data_grid/focus/m_focus.ts	Casts `_dataSource` for grouped focus calculations under stricter typing.
packages/devextreme/js/__internal/grids/data_grid/export/m_export.ts	Adds null-safe access for `_dataController._dataSource` remoteOperations usage.

Suppressed comments (2)

packages/devextreme/js/__internal/grids/grid_core/data_source_adapter/m_data_source_adapter.ts:130

Same receiver-binding issue as above: paginate/requireTotalCount are invoked as unbound function values, which can break if the DataSource method uses this. Call them via this._dataSource to preserve this.

  public paginate(): boolean | undefined;
  public paginate(value: boolean): void;
  public paginate(value?: boolean): boolean | undefined {
    return (this._dataSource.paginate as (...a: unknown[]) => boolean | undefined)(value);
  }

packages/devextreme/js/__internal/grids/grid_core/data_controller/data_controller.ts:1788

push is invoked as an unbound function value, which can break if the adapter implementation relies on this. Call it as a method on _dataSource to preserve the receiver.

  public push(...args: unknown[]): unknown {
    return (this._dataSource?.push as ((...a: unknown[]) => unknown) | undefined)?.(...args);
  }

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…mock cancel returns boolean

Copilot

Pull request overview

Copilot reviewed 15 out of 15 changed files in this pull request and generated 5 comments.

Suppressed comments (2)

packages/devextreme/js/__internal/grids/grid_core/virtual_scrolling/extenders/virtual_scrolling_data_controller.ts:562

Same issue as above: arguments as unknown as [] is an empty-tuple cast that hides the forwarded argument list. Prefer the established arguments as any delegation pattern used throughout this file.

    return dataSource?.viewportItemSize.apply(dataSource, arguments as unknown as []);

packages/devextreme/js/__internal/grids/grid_core/virtual_scrolling/extenders/virtual_scrolling_data_controller.ts:574

Same delegation typing issue: arguments as unknown as [] suggests an empty argument list. Prefer arguments as any (consistent with other .apply calls in this file).

      dataSource?.setViewportPosition.apply(dataSource, arguments as unknown as []);

…h repo pattern

Copilot

Pull request overview

Copilot reviewed 15 out of 15 changed files in this pull request and generated 3 comments.

Suppressed comments (5)

packages/devextreme/js/__internal/grids/grid_core/data_source_adapter/m_data_source_adapter.ts:112

This delegate calls DataSource.sort as an unbound function, which drops the DataSource this context and can break (DataSource.sort uses instance state). Invoke via property access to preserve this.

  public sort(): StoreLoadOptions['sort'];
  public sort(sortExpr: StoreLoadOptions['sort']): void;
  public sort(...args: unknown[]): unknown {
    return (this._dataSource.sort as (...a: unknown[]) => unknown)(...args);
  }

packages/devextreme/js/__internal/grids/grid_core/data_source_adapter/m_data_source_adapter.ts:118

This delegate calls DataSource.group as an unbound function, which drops the DataSource this context and can break (DataSource.group uses instance state). Invoke via property access to preserve this.

  public group(): StoreLoadOptions['group'];
  public group(groupExpr: StoreLoadOptions['group']): void;
  public group(...args: unknown[]): unknown {
    return (this._dataSource.group as (...a: unknown[]) => unknown)(...args);
  }

packages/devextreme/js/__internal/grids/grid_core/data_source_adapter/m_data_source_adapter.ts:124

This delegate calls DataSource.select as an unbound function, which drops the DataSource this context and can break (DataSource.select uses instance state). Invoke via property access to preserve this.

  public select(): StoreLoadOptions['select'];
  public select(selectExpr: StoreLoadOptions['select']): void;
  public select(...args: unknown[]): unknown {
    return (this._dataSource.select as (...a: unknown[]) => unknown)(...args);
  }

packages/devextreme/js/__internal/grids/grid_core/data_source_adapter/m_data_source_adapter.ts:130

This delegate calls DataSource.paginate as an unbound function, which drops the DataSource this context and will break (DataSource.paginate reads/writes instance fields). Invoke via property access to preserve this.

  public paginate(): boolean | undefined;
  public paginate(value: boolean): void;
  public paginate(value?: boolean): boolean | undefined {
    return (this._dataSource.paginate as (...a: unknown[]) => boolean | undefined)(value);
  }

packages/devextreme/js/__internal/grids/grid_core/data_source_adapter/m_data_source_adapter.ts:136

This delegate calls DataSource.requireTotalCount as an unbound function, which drops the DataSource this context and will break (DataSource.requireTotalCount reads/writes instance fields). Invoke via property access to preserve this.

  public requireTotalCount(): StoreLoadOptions['requireTotalCount'];
  public requireTotalCount(value: boolean): void;
  public requireTotalCount(value?: boolean): unknown {
    return (this._dataSource.requireTotalCount as (...a: unknown[]) => unknown)(value);
  }

Tucchhaa · 2026-08-31T08:56:57Z

-
-    // TODO: remove copying dataSource's members
-    each(dataSource, (memberName, member) => {
-      if (!that[memberName] && isFunction(member)) {
-        that[memberName] = function () {
-          return this._dataSource[memberName].apply(this._dataSource, arguments);
-        };
-      }
-    });


I suggest to remove this code from m_data_source.ts since it's not needed anymore:
https://github.com/DevExpress/DevExtreme/blob/main/packages/devextreme/js/__internal/data/data_source/data_source.ts#L792-L808

Tucchhaa · 2026-08-31T10:10:56Z

  public getDataSource(): DataSource | null | undefined {
-    const adapter: DataSourceAdapterLike | null | undefined = this._dataSource;
+    const adapter = this._dataSource as unknown as DataSourceAdapterLike | null | undefined;
    return adapter ? adapter._dataSource : null;
  }


public getDataSource(): DataSource | undefined { return this._dataSource?._dataSource; }

then make DataSourceAdapter._dataSource to be public and delete DataSourceAdapterLike type as it is not used anywhere else

Tucchhaa · 2026-08-31T10:14:27Z

          this._applyFilter();
        } else {
-          this._currentOperationTypes = dataSource.operationTypes();
+          this._currentOperationTypes = dataSource.operationTypes() ?? null;


Maybe move this normalization to DataSourceAdapter.operationTypes()?:

public operationTypes(): OperationTypes | null { return this._operationTypes ?? null; }

Tucchhaa · 2026-08-31T10:15:15Z

          this._isPaging = false;
          result.resolve(...args);
-        }).fail(result.reject);
+        }).fail(result.reject as (...args: unknown[]) => void);


let's avoid usage of as:
.fail((...args: unknown[]) => { result.reject(...args); })

Tucchhaa · 2026-08-31T10:17:50Z

        dataSource.load(loadOptions)
-          .done((loadedItems: RawItemData[], extra: LoadOperation['extra']): void => {
+          .done((loadedItems: unknown, extra: unknown): void => {
            const items = this._processItems(
-              this._beforeProcessItems(loadedItems),
+              this._beforeProcessItems(loadedItems as RawItemData[]),
              { changeType: 'loadingAll' },
            );
            // @ts-expect-error DataGrid-only summary leaks into grid_core
-            d.resolve(items, extra?.summary);
+            d.resolve(items, (extra as LoadOperation['extra'])?.summary);
          })
-          .fail(d.reject);
+          .fail(d.reject as (...args: unknown[]) => void);


Can keep these as for now, since this method will be refactored in the PR with CustomLoadPipeline:
https://github.com/DevExpress/DevExtreme/pull/34985/changes#diff-2fcaa9c5b931f7dac59f24898189fb29e1e4376b3f81f7ae612f670f6f195d04R1498-R1511

Tucchhaa · 2026-08-31T10:21:53Z

    }

-    const pageIndex = dataSource.pageIndex();
+    const pageIndex = dataSource.pageIndex() as unknown as number;


I suggest to rewrite this to:

// @ts-expect-error badly typed DataSourceAdapter const pageIndex: number = dataSource.pageIndex();

Because if we add types to DataSourceAdapter.pageIndex(), the ts will not show the error about redundant cast

Tucchhaa · 2026-08-31T10:22:24Z


-    const loadResult: DeferredObj<unknown> = dataSource[optionName === 'pageIndex' ? 'load' : 'reload']();
+    const loadResult: DeferredObj<unknown> = (
+      dataSource[optionName === 'pageIndex' ? 'load' : 'reload'] as () => DeferredObj<unknown>


let's use @ts-expect-error instead of as

Tucchhaa · 2026-08-31T10:22:40Z


  public push(...args: unknown[]): unknown {
-    return this._dataSource?.push(...args);
+    return (this._dataSource?.push as ((...a: unknown[]) => unknown) | undefined)?.(...args);


let's use @ts-expect-error instead of as

Tucchhaa · 2026-08-31T10:24:10Z

  private changingHandlerProxy!: (e: ChangingEvent) => void;

-  protected store!: () => any;
+  public filter(): StoreLoadOptions['filter'];


I suggest to move all getters to a place after init()

Tucchhaa · 2026-08-31T10:28:11Z

      return deferred.resolve(-1).promise();
    }

    if (!dataSource._grouping._updatePagingOptions) {


add @ts-expect-error here and remove as any from here:
https://github.com/DevExpress/DevExtreme/pull/34980/changes#diff-f03368d4500b8ecb4fbf076a07c3307cc0dca776f94f936f3e45e0d62be02c57R91

Tucchhaa · 2026-08-31T10:28:35Z

  private collapseAll(groupIndex: number): void {
-    const dataSource = this._dataSource;
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const dataSource = this._dataSource as any;


use @ts-expect-error where needed instead of casting to any

Tucchhaa · 2026-08-31T10:28:39Z

  private expandAll(groupIndex: number): void {
-    const dataSource = this._dataSource;
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const dataSource = this._dataSource as any;


use @ts-expect-error where needed instead of casting to any

Tucchhaa · 2026-08-31T10:28:44Z

  protected changeRowExpandCore(key: RowKey): DeferredObj<unknown> {
-    const dataSource = this._dataSource;
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const dataSource = this._dataSource as any;


use @ts-expect-error where needed instead of casting to any

Tucchhaa · 2026-08-31T10:28:48Z

  private isRowExpanded(key: RowKey): boolean {
-    return !!this._dataSource?.isRowExpanded(key);
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    return !!(this._dataSource as any)?.isRowExpanded(key);


use @ts-expect-error where needed instead of casting to any

Tucchhaa · 2026-08-31T10:28:56Z

    const summaryItemIndex = getSummaryItemIndex(this.option('summary.totalItems'), summaryItemName);
-    const aggregates = this._dataSource.totalAggregates();
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const aggregates = (this._dataSource as any).totalAggregates();


use @ts-expect-error instead of casting to any

Tucchhaa · 2026-08-31T10:29:04Z

    if (dataSource && summaryTotalItems?.length) {
-      const totalAggregates = dataSource.totalAggregates();
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      const totalAggregates = (dataSource as any).totalAggregates();


use @ts-expect-error instead of casting to any

Tucchhaa · 2026-08-31T10:29:45Z

        result = result || [];
        if (isLocalOperations) {
-          result.push({ selector: dataSource.getDataIndexGetter(), desc: false });
+          result.push({ selector: dataSource!.getDataIndexGetter(), desc: false });


Why ! instead ??

Tucchhaa · 2026-08-31T10:30:55Z

+      if ((data as unknown[]).length > 0) {
+        filter = this._generateOperationFilterByKey(key, (data as unknown[])[0], useGroup);


please avoid usage of as

Tucchhaa · 2026-08-31T10:32:32Z

  public reload(reload?: boolean, changesOnly?: boolean): DeferredObj<unknown> {
    const rowsScrollController = this._rowsScrollController || this._dataSource;
-    const itemIndex = rowsScrollController?.getItemIndexByPosition();
+    const itemIndex = (rowsScrollController as any)?.getItemIndexByPosition();


please avoid usage of as any in this file, use @ts-expect-error instead

Tucchhaa · 2026-08-31T10:34:25Z

    }

-    return dataSource?.viewportSize.apply(dataSource, arguments);
+    return dataSource?.viewportSize.apply(dataSource, arguments as any);


propagate args directly:
return dataSource?.viewportSize();
Same applies to viewportHeight, setViewportPosition

…s, reorder getters, drop dead enumerable shim, remove that=this

Copilot

Pull request overview

Copilot reviewed 16 out of 16 changed files in this pull request and generated 2 comments.

Suppressed comments (2)

Previously missed (1) — in code that hasn't changed since the last review.

packages/devextreme/js/__internal/grids/grid_core/data_source_adapter/m_data_source_adapter.ts:200

The proxy methods (select/paginate/requireTotalCount) also call unbound DataSource functions; this can break because this is lost. Use .apply/.call with this._dataSource to preserve DataSource instance context.

  public select(): StoreLoadOptions['select'];
  public select(selectExpr: StoreLoadOptions['select']): void;
  public select(...args: unknown[]): unknown {
    return (this._dataSource.select as (...a: unknown[]) => unknown)(...args);
  }

packages/devextreme/js/__internal/grids/grid_core/data_source_adapter/m_data_source_adapter.ts:170

The proxy methods (filter/sort/group) call the DataSource functions without binding this, so any DataSource implementation that relies on instance state will break (because this becomes undefined). Delegate via .apply(this._dataSource, args) (see existing pattern in pivot_grid/remote_store/m_remote_store.ts).

  public filter(): StoreLoadOptions['filter'];
  public filter(filterExpr: StoreLoadOptions['filter']): void;
  public filter(...args: unknown[]): unknown {
    return (this._dataSource.filter as (...a: unknown[]) => unknown)(...args);
  }

…ap relies on it too

Copilot

Pull request overview

Copilot reviewed 15 out of 15 changed files in this pull request and generated 3 comments.

Suppressed comments (1)

packages/devextreme/js/__internal/grids/grid_core/focus/m_focus.ts:552

getSortDataSourceParameters can now push a sort descriptor with selector: undefined when _dataController._dataSource is not set. Because isLocalOperations becomes true for an empty remoteOperations object, the dataSource?.getDataIndexGetter() optional call will yield undefined and can break downstream sorting logic. Fall back to sorting by the not-sorted key fields when dataSource is missing.

      if (notSortedKeys.length) {
        result = result || [];
        if (isLocalOperations) {
          result.push({ selector: dataSource?.getDataIndexGetter(), desc: false });
        } else {
          notSortedKeys.forEach((notSortedKey) => result.push({ selector: notSortedKey, desc: false }));
        }

bit-byte0 added 2 commits August 29, 2026 01:38

refactor(dataSourceAdapter): replace dynamic member-copy with explici…

2c4531d

…t delegates

refactor(dataController): type _dataSource as DataSourceAdapter

57d2a99

bit-byte0 added the 26_2 label Aug 29, 2026

bit-byte0 self-assigned this Aug 29, 2026

bit-byte0 added 3 commits August 29, 2026 21:07

Merge remote-tracking branch 'upstream/main' into refactor/gridcore-d…

9f1bee8

…atacontroller-type-datasource-adapter-26_2 # Conflicts: # packages/devextreme/js/__internal/grids/data_grid/grouping/m_grouping.ts

fix(dataSourceAdapter): add beginLoading/endLoading delegates missed …

3ca0c3b

…in de-proxy

fix(dataController): allow null _dataSource + complete MockGridDataSo…

1a292cc

…urce for unconditional delegates

bit-byte0 marked this pull request as ready for review August 31, 2026 06:46

bit-byte0 requested a review from a team as a code owner August 31, 2026 06:46

Copilot AI lite review requested due to automatic review settings August 31, 2026 06:46

Copilot started reviewing on behalf of bit-byte0 August 31, 2026 06:46 View session