feat(scale): add reverse operator

packages/vx-scale/src/operators/reverse.ts

@@ -0,0 +1,26 @@
+import { DefaultThresholdInput, D3Scale } from '../types/Scale';
+import { StringLike } from '../types/Base';
+import { ScaleConfigWithoutType } from '../types/ScaleConfig';
+
+export default function applyReverse<
+  Output,
+  DiscreteInput extends StringLike,
+  ThresholdInput extends DefaultThresholdInput
+>(
+  scale: D3Scale<Output, DiscreteInput, ThresholdInput>,
+  config: ScaleConfigWithoutType<Output, DiscreteInput, ThresholdInput>,
+) {
+  if (config.reverse) {
+    const reversedRange = scale
+      .range()
+      .slice()
+      .reverse();
+    if ('padding' in scale) {
+      // point and band scales
+      scale.range(reversedRange as [number, number]);
+    } else {
+      // the rest
+      scale.range(reversedRange as Output[]);
+    }
+  }
+}

packages/vx-scale/src/operators/scaleOperator.ts

@@ -11,6 +11,7 @@ import exponent from './exponent';
 import interpolate from './interpolate';
 import nice from './nice';
 import padding from './padding';
+import reverse from './reverse';
 import round from './round';
 import unknown from './unknown';
 import zero from './zero';
@@ -28,14 +29,17 @@ export const ALL_OPERATORS = [
   'interpolate',
   'round',
 
+  // set range then reverse
+  'range',
+  'reverse',
+
   // Order does not matter for these operators
   'align',
   'base',
   'clamp',
   'constant',
   'exponent',
   'padding',
-  'range',
   'unknown',
 ] as const;
 
@@ -55,6 +59,7 @@ const operators: Record<OperatorType, typeof domain> = {
   exponent,
   padding,
   range,
+  reverse,
   unknown,
 };
 

packages/vx-scale/src/scales/band.ts

@@ -6,6 +6,7 @@ import scaleOperator from '../operators/scaleOperator';
 export const updateBandScale = scaleOperator<'band'>(
   'domain',
   'range',
+  'reverse',
   'align',
   'padding',
   'round',

packages/vx-scale/src/scales/linear.ts

@@ -6,6 +6,7 @@ import scaleOperator from '../operators/scaleOperator';
 export const updateLinearScale = scaleOperator<'linear'>(
   'domain',
   'range',
+  'reverse',
   'clamp',
   'interpolate',
   'nice',

packages/vx-scale/src/scales/log.ts

@@ -6,6 +6,7 @@ import scaleOperator from '../operators/scaleOperator';
 export const updateLogScale = scaleOperator<'log'>(
   'domain',
   'range',
+  'reverse',
   'base',
   'clamp',
   'interpolate',

packages/vx-scale/src/scales/ordinal.ts

@@ -3,7 +3,7 @@ import { DefaultOutput, StringLike } from '../types/Base';
 import { PickScaleConfigWithoutType } from '../types/ScaleConfig';
 import scaleOperator from '../operators/scaleOperator';
 
-export const updateOrdinalScale = scaleOperator<'ordinal'>('domain', 'range', 'unknown');
+export const updateOrdinalScale = scaleOperator<'ordinal'>('domain', 'range', 'reverse', 'unknown');
 
 export default function createOrdinalScale<
   DiscreteInput extends StringLike = StringLike,

packages/vx-scale/src/scales/point.ts

@@ -6,6 +6,7 @@ import scaleOperator from '../operators/scaleOperator';
 export const updatePointScale = scaleOperator<'point'>(
   'domain',
   'range',
+  'reverse',
   'align',
   'padding',
   'round',

packages/vx-scale/src/scales/power.ts

@@ -6,6 +6,7 @@ import scaleOperator from '../operators/scaleOperator';
 export const updatePowScale = scaleOperator<'pow'>(
   'domain',
   'range',
+  'reverse',
   'clamp',
   'exponent',
   'interpolate',

packages/vx-scale/src/scales/quantile.ts

@@ -3,7 +3,7 @@ import { DefaultOutput } from '../types/Base';
 import { PickScaleConfigWithoutType } from '../types/ScaleConfig';
 import scaleOperator from '../operators/scaleOperator';
 
-export const updateQuantileScale = scaleOperator<'quantile'>('domain', 'range');
+export const updateQuantileScale = scaleOperator<'quantile'>('domain', 'range', 'reverse');
 
 export default function createQuantileScale<Output = DefaultOutput>(
   config?: PickScaleConfigWithoutType<'quantile', Output>,

packages/vx-scale/src/scales/quantize.ts

@@ -3,7 +3,13 @@ import { DefaultOutput } from '../types/Base';
 import { PickScaleConfigWithoutType } from '../types/ScaleConfig';
 import scaleOperator from '../operators/scaleOperator';
 
-export const updateQuantizeScale = scaleOperator<'quantize'>('domain', 'range', 'nice', 'zero');
+export const updateQuantizeScale = scaleOperator<'quantize'>(
+  'domain',
+  'range',
+  'reverse',
+  'nice',
+  'zero',
+);
 
 export default function createQuantizeScale<Output = DefaultOutput>(
   config?: PickScaleConfigWithoutType<'quantize', Output>,

packages/vx-scale/src/scales/squareRoot.ts

@@ -6,6 +6,7 @@ import scaleOperator from '../operators/scaleOperator';
 export const updateSqrtScale = scaleOperator<'sqrt'>(
   'domain',
   'range',
+  'reverse',
   'clamp',
   'interpolate',
   'nice',

packages/vx-scale/src/scales/symlog.ts

@@ -6,6 +6,7 @@ import scaleOperator from '../operators/scaleOperator';
 export const updateSymlogScale = scaleOperator<'symlog'>(
   'domain',
   'range',
+  'reverse',
   'clamp',
   'constant',
   'nice',

packages/vx-scale/src/scales/threshold.ts

@@ -4,7 +4,7 @@ import { PickScaleConfigWithoutType } from '../types/ScaleConfig';
 import { DefaultThresholdInput } from '../types/Scale';
 import scaleOperator from '../operators/scaleOperator';
 
-export const updateThresholdScale = scaleOperator<'threshold'>('domain', 'range');
+export const updateThresholdScale = scaleOperator<'threshold'>('domain', 'range', 'reverse');
 
 export default function createThresholdScale<
   ThresholdInput extends DefaultThresholdInput = DefaultThresholdInput,

packages/vx-scale/src/scales/time.ts

@@ -6,6 +6,7 @@ import scaleOperator from '../operators/scaleOperator';
 export const updateTimeScale = scaleOperator<'time'>(
   'domain',
   'range',
+  'reverse',
   'clamp',
   'interpolate',
   'nice',

packages/vx-scale/src/scales/utc.ts

@@ -6,6 +6,7 @@ import scaleOperator from '../operators/scaleOperator';
 export const updateUtcScale = scaleOperator<'utc'>(
   'domain',
   'range',
+  'reverse',
   'clamp',
   'interpolate',
   'nice',

packages/vx-scale/src/types/ScaleConfig.ts

@@ -17,7 +17,7 @@ export type ContinuousDomain = ContinuousInput[];
 // and add `type` property as discriminant of union type.
 type CreateScaleConfig<T, D, R, Fields extends keyof BaseScaleConfig<T, D, R> = 'type'> = Pick<
   BaseScaleConfig<T, D, R>,
-  'type' | 'domain' | 'range' | Fields
+  'type' | 'domain' | 'range' | 'reverse' | Fields
 >;
 
 export type LinearScaleConfig<Output = DefaultOutput> = CreateScaleConfig<

packages/vx-scale/test/scaleLinear.test.ts

@@ -13,6 +13,10 @@ describe('scaleLinear()', () => {
     const range = [1, 2];
     expect(scaleLinear({ range: [1, 2] }).range()).toEqual(range);
   });
+  it('set reverse', () => {
+    expect(scaleLinear({ reverse: true }).range()).toEqual([1, 0]);
+    expect(scaleLinear({ range: [1, 2], reverse: true }).range()).toEqual([2, 1]);
+  });
   describe('set clamp', () => {
     it('true', () => {
       const scale = scaleLinear({ clamp: true });

packages/vx-scale/test/scalePoint.test.ts

@@ -13,6 +13,10 @@ describe('scalePoint', () => {
     const scale = scalePoint({ range: [2, 3] });
     expect(scale.range()).toEqual([2, 3]);
   });
+  it('set reverse', () => {
+    expect(scalePoint({ reverse: true }).range()).toEqual([1, 0]);
+    expect(scalePoint({ range: [1, 2], reverse: true }).range()).toEqual([2, 1]);
+  });
   it('set align', () => {
     expect(scalePoint({ align: 0.5 }).align()).toEqual(0.5);
   });