Timeseries: Utilize min/max on stacking percentage (#95581)

* Bring in defined min/max into stacking range

* simplify logic

* different approach

---------

Co-authored-by: Leon Sorokin <leeoniya@gmail.com>

packages/grafana-ui/src/components/uPlot/config/UPlotScaleBuilder.ts

@@ -1,7 +1,7 @@
 import uPlot, { Scale, Range } from 'uplot';
 
 import { DecimalCount, incrRoundDn, incrRoundUp, isBooleanUnit } from '@grafana/data';
-import { ScaleOrientation, ScaleDirection, ScaleDistribution } from '@grafana/schema';
+import { ScaleOrientation, ScaleDirection, ScaleDistribution, StackingMode } from '@grafana/schema';
 
 import { PlotConfigBuilder } from '../types';
 
@@ -20,6 +20,7 @@ export interface ScaleProps {
   linearThreshold?: number;
   centeredZero?: boolean;
   decimals?: DecimalCount;
+  stackingMode?: StackingMode;
 }
 
 export class UPlotScaleBuilder extends PlotConfigBuilder<ScaleProps, Scale> {
@@ -41,8 +42,19 @@ export class UPlotScaleBuilder extends PlotConfigBuilder<ScaleProps, Scale> {
       orientation,
       centeredZero,
       decimals,
+      stackingMode,
     } = this.props;
 
+    if (stackingMode === StackingMode.Percent) {
+      if (hardMin == null && softMin == null) {
+        softMin = 0;
+      }
+
+      if (hardMax == null && softMax == null) {
+        softMax = 1;
+      }
+    }
+
     const distr = this.props.distribution;
 
     const distribution = !isTime

public/app/core/components/TimeSeries/utils.ts

@@ -247,14 +247,9 @@ export const preparePlotConfigBuilder: UPlotConfigPrepFn = ({
           softMin: customConfig.axisSoftMin,
           softMax: customConfig.axisSoftMax,
           centeredZero: customConfig.axisCenteredZero,
+          stackingMode: customConfig.stacking?.mode,
           range:
-            customConfig.stacking?.mode === StackingMode.Percent
+            field.type === FieldType.enum
-              ? (u: uPlot, dataMin: number, dataMax: number) => {
-                  dataMin = dataMin < 0 ? -1 : 0;
-                  dataMax = dataMax > 0 ? 1 : 0;
-                  return [dataMin, dataMax];
-                }
-              : field.type === FieldType.enum
               ? (u: uPlot, dataMin: number, dataMax: number) => {
                   // this is the exhaustive enum (stable)
                   let len = field.config.type!.enum!.text!.length;