switch default clause

switch-default-clause-bad.ts

import { Track } from "../models/Track";

export class BackgroundImage {
 dimension: string;
 url: string;
}

export class BackgroundImageService {

 getBackgroundArt(track: Track): BackgroundImage {
   switch(track.getGenre()) {
     default:
       return null;
     case "hiphop":
       const hipHopImage: BackgroundImage = {dimension: 'small', 'url': 'https://unsplash.com/photos/Qcl98B8Bk3I'};
       return hipHopImage;
     case "jazz":
       const jazzImage : BackgroundImage = {dimension: 'small', 'url': 'https://unsplash.com/photos/dBWvUqBoOU8'};
       return jazzImage;
     case "rap":
       const rapImage : BackgroundImage = {dimension: 'small', 'url': 'https://unsplash.com/photos/auq_QbyIA34'};
       return rapImage;
     case "country":
       const countryImage: BackgroundImage = {dimension: 'small', 'url': 'https://unsplash.com/photos/RnFgs90NEHY'};
       return countryImage;
   }
 }
}

switch-default-clause-good.ts

getBackgroundArt(track: Track): BackgroundImage {
 switch(track.getGenre()) {
   case "hiphop":
     const hipHopImage: BackgroundImage = {dimension: 'small', 'url': 'https://unsplash.com/photos/Qcl98B8Bk3I'};
     return hipHopImage;
   case "jazz":
     const jazzImage : BackgroundImage = {dimension: 'small', 'url': 'https://unsplash.com/photos/dBWvUqBoOU8'};
     return jazzImage;
   case "rap":
     const rapImage : BackgroundImage = {dimension: 'small', 'url': 'https://unsplash.com/photos/auq_QbyIA34'};
     return rapImage;
   case "country":
     const countryImage: BackgroundImage = {dimension: 'small', 'url': 'https://unsplash.com/photos/RnFgs90NEHY'};
     return countryImage;
   default:
     return null;
 }
}