Added unit tests for getPalette.

src/plugins/vis_types/timeseries/public/convert_to_lens/lib/configurations/metric/index.ts

@@ -50,7 +50,7 @@ export const getConfigurationForMetric = (
     return null;
   }
 
-  const palette = getPalette(model);
+  const palette = getPalette(model.background_color_rules ?? []);
   if (palette === null) {
     return null;
   }

src/plugins/vis_types/timeseries/public/convert_to_lens/lib/configurations/metric/palette.test.ts

@@ -0,0 +1,177 @@
+/*
+ * 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 { getPalette } from './palette';
+
+describe('getPalette', () => {
+  const invalidRules = [
+    { id: 'some-id-0' },
+    { id: 'some-id-1', value: 10 },
+    { id: 'some-id-2', operator: 'gte' },
+    { id: 'some-id-3', color: '#000' },
+    { id: 'some-id-4', background_color: '#000' },
+  ];
+  test('should return undefined if no filled rules was provided', () => {
+    expect(getPalette([])).toBeUndefined();
+    expect(getPalette(invalidRules)).toBeUndefined();
+  });
+
+  test('should return undefined if only one valid rule is provided and it is not lte', () => {
+    expect(getPalette([])).toBeUndefined();
+    expect(
+      getPalette([
+        ...invalidRules,
+        { id: 'some-id-5', operator: 'gt', value: 100, background_color: '#000' },
+      ])
+    ).toBeUndefined();
+  });
+
+  test('should return custom palette if only one valid rule is provided and it is lte', () => {
+    expect(getPalette([])).toBeUndefined();
+    expect(
+      getPalette([
+        ...invalidRules,
+        { id: 'some-id-5', operator: 'lte', value: 100, background_color: '#000' },
+      ])
+    ).toEqual({
+      name: 'custom',
+      params: {
+        colorStops: [{ color: '#000000', stop: 100 }],
+        continuity: 'below',
+        maxSteps: 5,
+        name: 'custom',
+        progression: 'fixed',
+        rangeMax: 100,
+        rangeMin: -Infinity,
+        rangeType: 'number',
+        reverse: false,
+        steps: 1,
+        stops: [{ color: '#000000', stop: 100 }],
+      },
+      type: 'palette',
+    });
+  });
+
+  test('should return undefined if more than two types of rules', () => {
+    expect(getPalette([])).toBeUndefined();
+    expect(
+      getPalette([
+        ...invalidRules,
+        { id: 'some-id-5', operator: 'lte', value: 100, background_color: '#000' },
+        { id: 'some-id-6', operator: 'gte', value: 150, background_color: '#000' },
+        { id: 'some-id-7', operator: 'lt', value: 200, background_color: '#000' },
+      ])
+    ).toBeUndefined();
+  });
+
+  test('should return undefined if two types of rules and last rule is not lte', () => {
+    expect(getPalette([])).toBeUndefined();
+    expect(
+      getPalette([
+        ...invalidRules,
+        { id: 'some-id-5', operator: 'gte', value: 100, background_color: '#000' },
+        { id: 'some-id-7', operator: 'lt', value: 200, background_color: '#000' },
+        { id: 'some-id-6', operator: 'gte', value: 150, background_color: '#000' },
+      ])
+    ).toBeUndefined();
+  });
+
+  test('should return undefined if all rules are lte', () => {
+    expect(getPalette([])).toBeUndefined();
+    expect(
+      getPalette([
+        ...invalidRules,
+        { id: 'some-id-5', operator: 'lte', value: 100, background_color: '#000' },
+        { id: 'some-id-7', operator: 'lte', value: 200, background_color: '#000' },
+        { id: 'some-id-6', operator: 'lte', value: 150, background_color: '#000' },
+      ])
+    ).toBeUndefined();
+  });
+
+  test('should return undefined if two types of rules and all except last one are lt and last one is not lte', () => {
+    expect(getPalette([])).toBeUndefined();
+    expect(
+      getPalette([
+        ...invalidRules,
+        { id: 'some-id-5', operator: 'lt', value: 100, background_color: '#000' },
+        { id: 'some-id-7', operator: 'gte', value: 200, background_color: '#000' },
+        { id: 'some-id-6', operator: 'lt', value: 150, background_color: '#000' },
+      ])
+    ).toBeUndefined();
+  });
+
+  test('should return custom palette if two types of rules and all except last one is lt and last one is lte', () => {
+    expect(getPalette([])).toBeUndefined();
+    expect(
+      getPalette([
+        ...invalidRules,
+        { id: 'some-id-5', operator: 'lt', value: 100, background_color: '#000' },
+        { id: 'some-id-7', operator: 'lte', value: 200, background_color: '#000' },
+        { id: 'some-id-6', operator: 'lt', value: 150, background_color: '#000' },
+      ])
+    ).toEqual({
+      name: 'custom',
+      params: {
+        colorStops: [
+          { color: '#000000', stop: -Infinity },
+          { color: '#000000', stop: 100 },
+          { color: '#000000', stop: 150 },
+        ],
+        continuity: 'below',
+        maxSteps: 5,
+        name: 'custom',
+        progression: 'fixed',
+        rangeMax: 200,
+        rangeMin: -Infinity,
+        rangeType: 'number',
+        reverse: false,
+        steps: 4,
+        stops: [
+          { color: '#000000', stop: 100 },
+          { color: '#000000', stop: 150 },
+          { color: '#000000', stop: 200 },
+        ],
+      },
+      type: 'palette',
+    });
+  });
+
+  test('should return custom palette if last one is lte and all previous are gte', () => {
+    expect(getPalette([])).toBeUndefined();
+    expect(
+      getPalette([
+        ...invalidRules,
+        { id: 'some-id-5', operator: 'gte', value: 100, background_color: '#000' },
+        { id: 'some-id-7', operator: 'lte', value: 200, background_color: '#000' },
+        { id: 'some-id-6', operator: 'gte', value: 150, background_color: '#000' },
+      ])
+    ).toEqual({
+      name: 'custom',
+      params: {
+        colorStops: [
+          { color: '#000000', stop: 100 },
+          { color: '#000000', stop: 150 },
+        ],
+        continuity: 'none',
+        maxSteps: 5,
+        name: 'custom',
+        progression: 'fixed',
+        rangeMax: 200,
+        rangeMin: 100,
+        rangeType: 'number',
+        reverse: false,
+        steps: 2,
+        stops: [
+          { color: '#000000', stop: 150 },
+          { color: '#000000', stop: 200 },
+        ],
+      },
+      type: 'palette',
+    });
+  });
+});

src/plugins/vis_types/timeseries/public/convert_to_lens/lib/configurations/metric/palette.ts

@@ -155,9 +155,11 @@ const getCustomPalette = (
   };
 };
 
-export const getPalette = (model: Panel): PaletteOutput<CustomPaletteParams> | null | undefined => {
+export const getPalette = (
+  rules: Exclude<Panel['background_color_rules'], undefined>
+): PaletteOutput<CustomPaletteParams> | null | undefined => {
   const validRules =
-    model.background_color_rules?.filter(
+    rules.filter(
       ({ operator, color: textColor, value, background_color: bColor }) =>
         operator && (bColor ?? textColor) && value !== undefined
     ) ?? [];