fix: add field from scale-range to aggregate groupby

build/vega-lite-schema.json

@@ -10391,6 +10391,18 @@
       },
       "type": "object"
     },
+    "FieldRange": {
+      "additionalProperties": false,
+      "properties": {
+        "field": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "field"
+      ],
+      "type": "object"
+    },
     "FieldRangePredicate": {
       "additionalProperties": false,
       "properties": {
@@ -21069,16 +21081,7 @@
               "type": "array"
             },
             {
-              "additionalProperties": false,
-              "properties": {
-                "field": {
-                  "type": "string"
-                }
-              },
-              "required": [
-                "field"
-              ],
-              "type": "object"
+              "$ref": "#/definitions/FieldRange"
             }
           ],
           "description": "The range of the scale. One of:\n\n- A string indicating a [pre-defined named scale range](https://vega.github.io/vega-lite/docs/scale.html#range-config) (e.g., example, `\"symbol\"`, or `\"diverging\"`).\n\n- For [continuous scales](https://vega.github.io/vega-lite/docs/scale.html#continuous), two-element array indicating  minimum and maximum values, or an array with more than two entries for specifying a [piecewise scale](https://vega.github.io/vega-lite/docs/scale.html#piecewise).\n\n- For [discrete](https://vega.github.io/vega-lite/docs/scale.html#discrete) and [discretizing](https://vega.github.io/vega-lite/docs/scale.html#discretizing) scales, an array of desired output values or an object with a `field` property representing the range values.  For example, if a field `color` contains CSS color names, we can set `range` to `{field: \"color\"}`.\n\n__Notes:__\n\n1) For color scales you can also specify a color [`scheme`](https://vega.github.io/vega-lite/docs/scale.html#scheme) instead of `range`.\n\n2) Any directly specified `range` for `x` and `y` channels will be ignored. Range can be customized via the view's corresponding [size](https://vega.github.io/vega-lite/docs/size.html) (`width` and `height`)."

src/compile/data/aggregate.ts

@@ -7,8 +7,9 @@ import {
   isGeoPositionChannel,
   isScaleChannel
 } from '../../channel';
-import {binRequiresRange, FieldDef, hasBandEnd, isTypedFieldDef, vgField} from '../../channeldef';
+import {binRequiresRange, FieldDef, hasBandEnd, isScaleFieldDef, isTypedFieldDef, vgField} from '../../channeldef';
 import * as log from '../../log';
+import {isFieldRange} from '../../scale';
 import {AggregateTransform} from '../../transform';
 import {Dict, duplicate, hash, keys, replacePathInField, setEqual} from '../../util';
 import {isUnitModel, ModelWithField} from '../model';
@@ -37,6 +38,9 @@ function addDimension(dims: Set<string>, channel: Channel, fieldDef: FieldDef<st
   } else {
     dims.add(vgField(fieldDef));
   }
+  if (isScaleFieldDef(fieldDef) && isFieldRange(fieldDef.scale?.range)) {
+    dims.add(fieldDef.scale.range.field);
+  }
   return dims;
 }
 

src/scale.ts

@@ -1,4 +1,5 @@
 import {
+  isObject,
   RangeEnum,
   ScaleBins,
   ScaleInterpolateEnum,
@@ -439,6 +440,14 @@ export function isDomainUnionWith(domain: Domain): domain is DomainUnionWith {
   return domain && domain['unionWith'];
 }
 
+export interface FieldRange {
+  field: string;
+}
+
+export function isFieldRange(range: any): range is FieldRange {
+  return isObject(range) && 'field' in range;
+}
+
 export interface Scale<ES extends ExprRef | SignalRef = ExprRef | SignalRef> {
   /**
    * The type of scale. Vega-Lite supports the following categories of scale types:
@@ -513,7 +522,7 @@ export interface Scale<ES extends ExprRef | SignalRef = ExprRef | SignalRef> {
    *
    * 2) Any directly specified `range` for `x` and `y` channels will be ignored. Range can be customized via the view's corresponding [size](https://vega.github.io/vega-lite/docs/size.html) (`width` and `height`).
    */
-  range?: RangeEnum | (number | string | number[] | ES)[] | {field: string};
+  range?: RangeEnum | (number | string | number[] | ES)[] | FieldRange;
 
   /**
    * Sets the maximum value in the scale range, overriding the `range` property or the default range. This property is only intended for use with scales having continuous ranges.

test/compile/data/aggregate.test.ts

@@ -196,6 +196,26 @@ describe('compile/data/aggregate', () => {
       });
     });
 
+    it('should add correct dimension when field is in scale range', () => {
+      const model = parseUnitModel({
+        mark: 'point',
+        encoding: {
+          x: {timeUnit: 'year', field: 'date'},
+          y: {aggregate: 'mean', field: 'Displacement', type: 'quantitative'},
+          color: {field: 'symbol', type: 'nominal', scale: {range: {field: 'color'}}}
+        }
+      });
+
+      const agg = AggregateNode.makeFromEncoding(null, model);
+      expect(agg.assemble()).toEqual({
+        type: 'aggregate',
+        groupby: ['year_date', 'symbol', 'color'],
+        ops: ['mean'],
+        fields: ['Displacement'],
+        as: ['mean_Displacement']
+      });
+    });
+
     it('adds correct measure for argmin/max', () => {
       const model = parseUnitModel({
         mark: 'point',