test(deck.gl): pin legend and point colors to the same slice_id key

Adds a regression test asserting that the legend path (getCategories)
and the point-color path (addColorToFeatures) both key the categorical
color scale on form_data's slice_id, and that legend swatches match the
resolved point colors per category. Exports getCategories to make the
legend path testable.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: rusackas

superset-frontend/plugins/preset-chart-deckgl/src/CategoricalDeckGLContainer.test.tsx

@@ -0,0 +1,68 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+import { QueryFormData } from '@superset-ui/core';
+import { getCategories } from './CategoricalDeckGLContainer';
+import { addColorToFeatures } from './utils/addColor';
+import { COLOR_SCHEME_TYPES } from './utilities/utils';
+
+// Record every (label, sliceId) pair the categorical color scale is asked to
+// resolve, so we can assert the legend and point-color paths key the scale on
+// the same slice id.
+const scaleCalls: [string, number | undefined][] = [];
+jest.mock('@superset-ui/core', () => {
+  const actual = jest.requireActual('@superset-ui/core');
+  return {
+    ...actual,
+    CategoricalColorNamespace: {
+      ...actual.CategoricalColorNamespace,
+      getScale: () => (value: string, sliceId?: number) => {
+        scaleCalls.push([value, sliceId]);
+        return value === 'A' ? '#ff0000' : '#00ff00';
+      },
+    },
+  };
+});
+
+test('legend and point colors resolve from the same slice_id', () => {
+  const fd = {
+    datasource: '1__table',
+    viz_type: 'deck_scatter',
+    color_scheme_type: COLOR_SCHEME_TYPES.categorical_palette,
+    color_scheme: 'supersetColors',
+    dimension: 'category',
+    slice_id: 42,
+    color_picker: { r: 0, g: 0, b: 0, a: 1 },
+  } as unknown as QueryFormData;
+  const data = [{ cat_color: 'A' }, { cat_color: 'B' }];
+
+  const categories = getCategories(fd, data);
+  const features = addColorToFeatures(data, fd);
+
+  // Both the legend path (getCategories) and the point-color path
+  // (addColorToFeatures) key the color scale on the same slice id.
+  expect(scaleCalls.length).toBeGreaterThan(0);
+  scaleCalls.forEach(([, sliceId]) => {
+    expect(sliceId).toBe(42);
+  });
+
+  // The legend swatch for each category matches the resolved point color.
+  expect(categories.A.color).toEqual(features[0].color);
+  expect(categories.B.color).toEqual(features[1].color);
+  expect(features[0].color).not.toEqual(features[1].color);
+});

superset-frontend/plugins/preset-chart-deckgl/src/CategoricalDeckGLContainer.tsx

@@ -55,7 +55,7 @@ import { addColorToFeatures } from './utils/addColor';
 
 const { getScale } = CategoricalColorNamespace;
 
-function getCategories(fd: QueryFormData, data: JsonObject[]) {
+export function getCategories(fd: QueryFormData, data: JsonObject[]) {
   const c = fd.color_picker || { r: 0, g: 0, b: 0, a: 1 };
   const fixedColor = [c.r, c.g, c.b, 255 * c.a];
   const appliedScheme = fd.color_scheme;