fix: [VIZ-4715] Added fix for Vega-Lite duplicated axis issue

src/compositemark/boxplot.ts

@@ -310,7 +310,6 @@ export function normalizeBoxPlot(
       [continuousAxis]: {
         field: continuousAxisChannelDef.field,
         type: continuousAxisChannelDef.type,
-        ...(title !== undefined ? {title} : {}),
         ...(scale !== undefined ? {scale} : {}),
         // add axis without title since we already added the title above
         ...(isEmpty(axisWithoutTitle) ? {} : {axis: axisWithoutTitle})
@@ -326,7 +325,12 @@ export function normalizeBoxPlot(
   if (outlierLayersMixins) {
     filteredLayersMixins = {
       transform: filteredLayersMixinsTransforms,
-      layer: [outlierLayersMixins, filteredWhiskerSpec]
+      layer: [outlierLayersMixins, filteredWhiskerSpec],
+      encoding: {
+        [continuousAxis]: {
+          ...(title !== undefined ? {title} : {})
+        }
+      }
     };
   } else {
     filteredLayersMixins = filteredWhiskerSpec;

src/spec/facet.ts

@@ -6,7 +6,7 @@ import {Header} from '../header';
 import {EncodingSortField, SortArray, SortOrder} from '../sort';
 import {StandardType} from '../type';
 import {BaseSpec, GenericCompositionLayoutWithColumns, ResolveMixins} from './base';
-import {GenericLayerSpec, NormalizedLayerSpec} from './layer';
+import {GenericLayerSpec, LayerSpec, NormalizedLayerSpec} from './layer';
 import {GenericUnitSpec, NormalizedUnitSpec} from './unit';
 
 export interface FacetFieldDef<F extends Field, ES extends ExprRef | SignalRef = ExprRef | SignalRef>
@@ -113,8 +113,11 @@ export function isFacetFieldDef<F extends Field>(channelDef: ChannelDef<F>): cha
 /**
  * Base interface for a facet specification.
  */
-export interface GenericFacetSpec<U extends GenericUnitSpec<any, any>, L extends GenericLayerSpec<any>, F extends Field>
-  extends BaseSpec,
+export interface GenericFacetSpec<
+  U extends GenericUnitSpec<any, any>,
+  L extends GenericLayerSpec<any> | LayerSpec<F>,
+  F extends Field
+> extends BaseSpec,
     GenericCompositionLayoutWithColumns,
     ResolveMixins {
   /**

src/spec/index.ts

@@ -32,7 +32,7 @@ export {isUnitSpec} from './unit';
  */
 export type GenericSpec<
   U extends GenericUnitSpec<Encoding<F>, any>,
-  L extends GenericLayerSpec<U>,
+  L extends GenericLayerSpec<U> | LayerSpec<F>,
   R extends RepeatSpec,
   F extends Field
 > =

src/spec/layer.ts

@@ -1,5 +1,6 @@
 import {Field} from '../channeldef';
 import {SharedCompositeEncoding} from '../compositemark';
+//import {Encoding} from '../encoding';
 import {ExprRef} from '../expr';
 import {Projection} from '../projection';
 import {BaseSpec, FrameMixins, ResolveMixins} from './base';
@@ -15,6 +16,7 @@ export interface GenericLayerSpec<U extends GenericUnitSpec<any, any>> extends B
    * __Note__: Specifications inside `layer` cannot use `row` and `column` channels as layering facet specifications is not allowed. Instead, use the [facet operator](https://vega.github.io/vega-lite/docs/facet.html) and place a layer inside a facet.
    */
   layer: (GenericLayerSpec<U> | U)[];
+  encoding?: SharedCompositeEncoding<any>;
 }
 
 /**