fix(deezer): never return empty-image-id placeholder pictures

adapters/deezer/deezer.go

@@ -70,16 +70,27 @@ func (s *deezerAgent) GetArtistImages(ctx context.Context, _, name, _ string) ([
 		{artist.PictureSmall, deezerApiPictureSmallSize},
 	}
 	for _, imgData := range possibleImages {
-		if imgData.URL != "" {
+		if imgData.URL != "" && !isPlaceholderPicture(imgData.URL) {
 			res = append(res, agents.ExternalImage{
 				URL:  imgData.URL,
 				Size: imgData.Size,
 			})
 		}
 	}
+	if len(res) == 0 {
+		return nil, agents.ErrNotFound
+	}
 	return res, nil
 }
 
+// deezerEmptyPicturePath is Deezer's empty-image-id path shape for artists with no picture
+// (…/images/artist//1000x1000-…), which serves a generic silhouette on any CDN host.
+const deezerEmptyPicturePath = "/images/artist//"
+
+func isPlaceholderPicture(url string) bool {
+	return strings.Contains(url, deezerEmptyPicturePath)
+}
+
 func (s *deezerAgent) searchArtist(ctx context.Context, name string) (*Artist, error) {
 	artists, err := s.client.searchArtists(ctx, name, deezerArtistSearchLimit)
 	if errors.Is(err, ErrNotFound) || len(artists) == 0 {

adapters/deezer/deezer_test.go

@@ -94,6 +94,54 @@ var _ = Describe("deezerAgent", func() {
 		})
 	})
 
+	Describe("GetArtistImages", func() {
+		var agent *deezerAgent
+		var httpClient *fakeHttpClient
+
+		BeforeEach(func() {
+			httpClient = &fakeHttpClient{}
+			agent = &deezerAgent{
+				dataStore: &tests.MockDataStore{},
+				client:    newClient(httpClient),
+			}
+		})
+
+		It("returns the real images when the artist has a picture", func() {
+			httpClient.mock("https://api.deezer.com/search/artist", http.Response{
+				StatusCode: 200,
+				Body: io.NopCloser(bytes.NewBufferString(`{"data":[
+					{"id":412,"name":"Queen","nb_fan":12744378,
+					 "picture_xl":"https://cdn-images.dzcdn.net/images/artist/abc/1000x1000-000000-80-0-0.jpg",
+					 "picture_big":"https://cdn-images.dzcdn.net/images/artist/abc/500x500-000000-80-0-0.jpg"}
+				],"total":1}`)),
+			})
+
+			images, err := agent.GetArtistImages(ctx, "", "Queen", "")
+
+			Expect(err).ToNot(HaveOccurred())
+			Expect(images).To(HaveLen(2))
+			Expect(images[0].URL).To(ContainSubstring("1000x1000"))
+		})
+
+		It("returns ErrNotFound when the artist only has empty-id placeholder pictures", func() {
+			httpClient.mock("https://api.deezer.com/search/artist", http.Response{
+				StatusCode: 200,
+				Body: io.NopCloser(bytes.NewBufferString(`{"data":[
+					{"id":412,"name":"Queen","nb_fan":12744378,
+					 "picture_xl":"https://cdn-images.dzcdn.net/images/artist//1000x1000-000000-80-0-0.jpg",
+					 "picture_big":"https://cdn-images.dzcdn.net/images/artist//500x500-000000-80-0-0.jpg",
+					 "picture_medium":"https://cdn-images.dzcdn.net/images/artist//250x250-000000-80-0-0.jpg",
+					 "picture_small":"https://cdn-images.dzcdn.net/images/artist//56x56-000000-80-0-0.jpg"}
+				],"total":1}`)),
+			})
+
+			images, err := agent.GetArtistImages(ctx, "", "Queen", "")
+
+			Expect(err).To(MatchError(agents.ErrNotFound))
+			Expect(images).To(BeEmpty())
+		})
+	})
+
 	Describe("GetArtistBiography - Language Fallback", func() {
 		var agent *deezerAgent
 		var httpClient *langAwareHttpClient