[Lens] improve metric palette behavior (#139596)

* handle single-value case

* match continuity between metric types

* fix collapse-by handling, polish logic

* update snapshot

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

src/plugins/chart_expressions/expression_metric/public/components/metric_vis.test.tsx

@@ -954,7 +954,7 @@ describe('MetricVisComponent', function () {
                 "stops": Array [],
               },
               Object {
-                "max": 28.984375,
+                "max": 57.96875,
                 "min": 0,
               },
             ],

src/plugins/chart_expressions/expression_metric/public/utils/palette_data_bounds.test.ts

@@ -0,0 +1,71 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { Datatable, DatatableRow } from '@kbn/expressions-plugin/common';
+import { getDataBoundsForPalette } from './palette_data_bounds';
+
+describe('palette data bounds', () => {
+  const buildTableWithRows = (rows: DatatableRow[]) => {
+    const table: Datatable = {
+      type: 'datatable',
+      columns: Object.keys(rows).map((key) => ({
+        id: key,
+        name: key,
+        meta: { type: 'number' },
+      })),
+      rows,
+    };
+
+    return table;
+  };
+
+  describe('single value scenarios', () => {
+    it('creates a range with the metric value in the middle', () => {
+      const accessors = {
+        metric: 'first',
+      };
+      expect(getDataBoundsForPalette(accessors, buildTableWithRows([{ first: 100 }]))).toEqual({
+        min: 0,
+        max: 200,
+      });
+      expect(getDataBoundsForPalette(accessors, buildTableWithRows([{ first: -100 }]))).toEqual({
+        min: -200,
+        max: 0,
+      });
+    });
+
+    it('uses maximum dimension when available', () => {
+      expect(
+        getDataBoundsForPalette(
+          { metric: 'metric', max: 'max' },
+          buildTableWithRows([{ metric: 200, max: 100 }])
+        )
+      ).toEqual({ min: 0, max: 100 });
+
+      expect(
+        getDataBoundsForPalette(
+          { metric: 'metric', max: 'max' },
+          buildTableWithRows([
+            { metric: 200, max: 100 },
+            { metric: 400, max: 150 },
+          ]),
+          1
+        )
+      ).toEqual({ min: 0, max: 150 });
+    });
+  });
+
+  it('uses minimum and maximum metric when breakdown but no max', () => {
+    expect(
+      getDataBoundsForPalette(
+        { metric: 'metric', breakdownBy: 'breakdown' },
+        buildTableWithRows([{ metric: -100 }, { metric: 100 }, { metric: 200 }, { metric: 300 }])
+      )
+    ).toEqual({ min: -100, max: 300 });
+  });
+});

src/plugins/chart_expressions/expression_metric/public/utils/palette_data_bounds.ts

@@ -19,6 +19,17 @@ export const getDataBoundsForPalette = (
 
   const smallestMetric = Math.min(...data.rows.map((row) => row[accessors.metric]));
   const greatestMetric = Math.max(...data.rows.map((row) => row[accessors.metric]));
+
+  if (
+    !accessors.max &&
+    !accessors.breakdownBy &&
+    (typeof rowNumber !== 'undefined' || data.rows.length === 1)
+  ) {
+    // dealing with a single metric and no max
+    const metricValue = greatestMetric;
+    return metricValue < 0 ? { min: metricValue * 2, max: 0 } : { min: 0, max: metricValue * 2 };
+  }
+
   const greatestMaximum = accessors.max
     ? rowNumber
       ? data.rows[rowNumber][accessors.max]

x-pack/plugins/lens/public/visualizations/legacy_metric/palette_config.tsx

@@ -15,6 +15,7 @@ export const defaultPaletteParams: RequiredPaletteParamTypes = {
   ...sharedDefaultParams,
   maxSteps: 5,
   name: DEFAULT_PALETTE_NAME,
+  continuity: 'all',
   rangeType: 'number',
   steps: DEFAULT_COLOR_STEPS,
 };

x-pack/plugins/lens/public/visualizations/metric/dimension_editor.tsx

@@ -267,14 +267,18 @@ function PrimaryMetricEditor(props: SubProps) {
 
   const hasDynamicColoring = Boolean(state?.palette);
 
-  const startWithPercentPalette = Boolean(state.maxAccessor || state.breakdownByAccessor);
+  const supportsPercentPalette = Boolean(
+    state.maxAccessor ||
+      (state.breakdownByAccessor && !state.collapseFn) ||
+      state?.palette?.params?.rangeType === 'percent'
+  );
 
   const activePalette = state?.palette || {
     type: 'palette',
-    name: (startWithPercentPalette ? defaultPercentagePaletteParams : defaultNumberPaletteParams)
+    name: (supportsPercentPalette ? defaultPercentagePaletteParams : defaultNumberPaletteParams)
       .name,
     params: {
-      ...(startWithPercentPalette ? defaultPercentagePaletteParams : defaultNumberPaletteParams),
+      ...(supportsPercentPalette ? defaultPercentagePaletteParams : defaultNumberPaletteParams),
     },
   };
 
@@ -282,7 +286,8 @@ function PrimaryMetricEditor(props: SubProps) {
     {
       metric: state.metricAccessor!,
       max: state.maxAccessor,
-      breakdownBy: state.breakdownByAccessor,
+      // if we're collapsing, pretend like there's no breakdown to match the activeData
+      breakdownBy: !state.collapseFn ? state.breakdownByAccessor : undefined,
     },
     frame.activeData?.[state.layerId]
   );
@@ -401,11 +406,7 @@ function PrimaryMetricEditor(props: SubProps) {
                     activePalette={activePalette}
                     dataBounds={currentMinMax}
                     displayInfinity={true}
-                    showRangeTypeSelector={Boolean(
-                      state.breakdownByAccessor ||
-                        state.maxAccessor ||
-                        activePalette.params?.rangeType === 'percent'
-                    )}
+                    showRangeTypeSelector={supportsPercentPalette}
                     setPalette={(newPalette) => {
                       setState({
                         ...state,