Fix stacking bar chart (#7516)

Author: yoshiokatsuneo

viz-lib/src/visualizations/chart/plotly/fixtures/prepareData/bar/normalized.json

@@ -48,7 +48,6 @@
     "series": [
       {
         "visible": true,
-        "offsetgroup": "0",
         "type": "bar",
         "name": "a",
         "x": ["x1", "x2", "x3", "x4"],
@@ -64,7 +63,6 @@
       },
       {
         "visible": true,
-        "offsetgroup": "1",
         "type": "bar",
         "name": "b",
         "x": ["x1", "x2", "x3", "x4"],

viz-lib/src/visualizations/chart/plotly/fixtures/prepareData/bar/stacked.json

@@ -48,7 +48,6 @@
     "series": [
       {
         "visible": true,
-        "offsetgroup": "0",
         "type": "bar",
         "name": "a",
         "x": ["x1", "x2", "x3", "x4"],
@@ -64,7 +63,6 @@
       },
       {
         "visible": true,
-        "offsetgroup": "1",
         "type": "bar",
         "name": "b",
         "x": ["x1", "x2", "x3", "x4"],

viz-lib/src/visualizations/chart/plotly/prepareDefaultData.ts

@@ -26,7 +26,9 @@ function getHoverInfoPattern(options: any) {
 
 function prepareBarSeries(series: any, options: any, additionalOptions: any) {
   series.type = "bar";
-  series.offsetgroup = toString(additionalOptions.index);
+  if (!options.series.stacking) {
+    series.offsetgroup = toString(additionalOptions.index);
+  }
   if (options.showDataLabels) {
     series.textposition = "inside";
   } else {