no else just return

1-no-else-just-return-bad.ts

getBackgroundArt(track: Track): BackgroundImage {
 let backgroundImage: BackgroundImage;
 switch(track.getGenre()) {
   case "hiphop":
     backgroundImage = {dimension: 'small', 'url': 'https://unsplash.com/photos/Qcl98B8Bk3I'};
     break;
   case "jazz":
     backgroundImage = {dimension: 'small', 'url': 'https://unsplash.com/photos/dBWvUqBoOU8'};
     break;
   case "rap":
     backgroundImage = {dimension: 'small', 'url': 'https://unsplash.com/photos/auq_QbyIA34'};
     break;
   case "country":
     backgroundImage = {dimension: 'small', 'url': 'https://unsplash.com/photos/RnFgs90NEHY'};
     break;
   default:
     backgroundImage = {dimension: 'small', url : 'https://unsplash.com/photos/PDX_a_82obo'};
 }
 return backgroundImage;
}

2-no-else-just-return-bad.ts

getBackgroundArt(track: Track): BackgroundImage {
 let backgroundImage: BackgroundImage;
 if(!track.getGenre()) {
   backgroundImage = {dimension: BackgroundImageDimensions.small, url : this.DEFAULT_BACKGROUND_IMAGE_URL};
 } else if (track.getGenre() == "hiphop") {
   backgroundImage = {dimension: BackgroundImageDimensions.small, url: this.HIPHOP_BACKGROUND_IMAGE_URL};
 } else if(track.getGenre() == "jazz") {
   backgroundImage = {dimension: BackgroundImageDimensions.small, url: this.JAZZ_BACKGROUND_IMAGE_URL};
 } else if(track.getGenre() == "rap") {
   backgroundImage = {dimension: BackgroundImageDimensions.small, url: this.RAP_BACKGROUND_IMAGE_URL};
 } else if(track.getGenre() == "country") {
   backgroundImage = {dimension: BackgroundImageDimensions.small, url: this.COUNTRY_BACKGROUND_IMAGE_URL};
 }
 return backgroundImage;
}

3-no-else-just-return-good.ts

getBackgroundArt(track: Track): BackgroundImage {
 let backgroundImage: BackgroundImage = {dimension: BackgroundImageDimensions.small, url : this.DEFAULT_BACKGROUND_IMAGE_URL};
 if (track.getGenre() == "hiphop") {
   return {dimension: BackgroundImageDimensions.small, url: this.HIPHOP_BACKGROUND_IMAGE_URL};
 }
 if(track.getGenre() == "jazz") {
   return {dimension: BackgroundImageDimensions.small, url: this.JAZZ_BACKGROUND_IMAGE_URL};
 }
 if(track.getGenre() == "rap") {
   return {dimension: BackgroundImageDimensions.small, url: this.RAP_BACKGROUND_IMAGE_URL};
 }
 if(track.getGenre() == "country") {
   return {dimension: BackgroundImageDimensions.small, url: this.COUNTRY_BACKGROUND_IMAGE_URL};
 }
 return backgroundImage;
}