Fix tests and lint errors, plus a bit of refactor

server/public/encode_id_test.go

@@ -0,0 +1,39 @@
+package public
+
+import (
+	"github.com/go-chi/jwtauth/v5"
+	"github.com/navidrome/navidrome/core/auth"
+	"github.com/navidrome/navidrome/model"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("encodeArtworkID", func() {
+	Context("Public ID Encoding", func() {
+		BeforeEach(func() {
+			auth.TokenAuth = jwtauth.New("HS256", []byte("super secret"), nil)
+		})
+		It("returns a reversible string representation", func() {
+			id := model.NewArtworkID(model.KindArtistArtwork, "1234")
+			encoded := encodeArtworkID(id)
+			decoded, err := decodeArtworkID(encoded)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(decoded).To(Equal(id))
+		})
+		It("fails to decode an invalid token", func() {
+			_, err := decodeArtworkID("xx-123")
+			Expect(err).To(MatchError("invalid JWT"))
+		})
+		It("defaults to kind mediafile", func() {
+			encoded := encodeArtworkID(model.ArtworkID{})
+			id, err := decodeArtworkID(encoded)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(id.Kind).To(Equal(model.KindMediaFileArtwork))
+		})
+		It("fails to decode a token without an id", func() {
+			token, _ := auth.CreatePublicToken(map[string]any{})
+			_, err := decodeArtworkID(token)
+			Expect(err).To(HaveOccurred())
+		})
+	})
+})