fix: bar smapling not work bug. fix#4571

common/changes/@visactor/vchart/fix-bug-for-sampling_2026-04-28-11-20.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@visactor/vchart",
+      "comment": "fix: bar smapling not work bug. fix#4571",
+      "type": "none"
+    }
+  ],
+  "packageName": "@visactor/vchart"
+}

packages/vchart/__tests__/unit/chart/bar.test.ts

@@ -149,6 +149,64 @@ describe('Bar chart test', () => {
     expect(series.fieldX2).toBeUndefined();
   });
 
+  test('Bar chart with lttb sampling should keep valid bar data', () => {
+    const samplingSpec = {
+      type: 'bar',
+      data: [
+        {
+          id: 'barData',
+          values: [
+            { month: 'Monday', sales: 22 },
+            { month: 'Tuesday', sales: 13 },
+            { month: 'Wednesday', sales: 25 },
+            { month: 'Thursday', sales: 29 },
+            { month: 'Friday', sales: 38 }
+          ]
+        }
+      ],
+      xField: 'month',
+      yField: 'sales',
+      sampling: 'lttb'
+    };
+    const transformer = new BarChart.transformerConstructor({
+      type: 'bar',
+      seriesType: 'bar',
+      getTheme: getTheme,
+      mode: 'desktop-browser'
+    });
+    const info = transformer.initChartSpec(samplingSpec as any);
+    chart = new BarChart(
+      samplingSpec as any,
+      {
+        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+        // @ts-ignore
+        eventDispatcher: new EventDispatcher({} as any, { addEventListener: () => {} } as any),
+        globalInstance: {
+          isAnimationEnable: () => true,
+          getContainer: () => ({}),
+          getTooltipHandlerByUser: (() => undefined) as () => undefined
+        },
+        render: {} as any,
+        dataSet,
+        map: new Map(),
+        container: null,
+        mode: 'desktop-browser',
+        getCompiler: getTestCompiler,
+        globalScale: new GlobalScale([], { getAllSeries: () => [] as any[] } as any),
+        getTheme: getTheme,
+        getSpecInfo: () => info
+      } as any
+    );
+    chart.created(transformer);
+    chart.init();
+
+    const series: BarSeries = chart.getAllSeries()[0] as BarSeries;
+    series.getRegion().setLayoutRect({ width: 500, height: 500 });
+    series.compile();
+
+    expect((series as any)._data.getProduct()).toHaveLength(5);
+  });
+
   test('stackCornerRadius should build valid clip paths when barMinHeight is enabled', () => {
     const stackSpec = {
       type: 'bar',

packages/vchart/src/series/bar/bar.ts

@@ -885,7 +885,7 @@ export class BarSeries<T extends IBarSeriesSpec = IBarSeriesSpec> extends Cartes
 
       this._data.setTransform([
         {
-          type: 'sampling',
+          type: 'dataSampling',
           size: this._direction === Direction.horizontal ? height : width,
           factor: this._spec.samplingFactor,
           yfield: this._direction === Direction.horizontal ? fieldsX[0] : fieldsY[0],