Query for genres

src/music_service.ts

@@ -25,17 +25,17 @@ export type AuthFailure = {
 export type ArtistSummary = {
   id: string;
   name: string;
-  image: Images
+  image: Images;
-}
+};
 
 export type Images = {
-  small: string | undefined,
+  small: string | undefined;
-  medium: string | undefined,
+  medium: string | undefined;
-  large: string | undefined,
+  large: string | undefined;
-}
+};
 
 export type Artist = ArtistSummary & {
-  albums: Album[]
+  albums: Album[];
 };
 
 export type AlbumSummary = {
@@ -43,11 +43,10 @@ export type AlbumSummary = {
   name: string;
   year: string | undefined;
   genre: string | undefined;
-}
-
-export type Album = AlbumSummary & {
 };
 
+export type Album = AlbumSummary & {};
+
 export type Paging = {
   _index: number;
   _count: number;
@@ -70,30 +69,33 @@ export const asResult = <T>([results, total]: [T[], number]) => ({
   total,
 });
 
-export type ArtistQuery = Paging
+export type ArtistQuery = Paging;
 
 export type AlbumQuery = Paging & {
-  artistId?: string
+  artistId?: string;
-  genre?: string
+  genre?: string;
-}
+};
 
-export const artistToArtistSummary = (
+export const artistToArtistSummary = (it: Artist): ArtistSummary => ({
-  it: Artist
-): ArtistSummary => ({
   id: it.id,
   name: it.name,
   image: it.image,
 });
 
-export const albumToAlbumSummary = (
+export const albumToAlbumSummary = (it: Album): AlbumSummary => ({
-  it: Album
-): AlbumSummary => ({
   id: it.id,
   name: it.name,
   year: it.year,
   genre: it.genre,
 });
 
+export const range = (size: number) => [...Array(size).keys()];
+
+export const asArtistAlbumPairs = (artists: Artist[]): [Artist, Album][] =>
+  artists.flatMap((artist) =>
+    artist.albums.map((album) => [artist, album] as [Artist, Album])
+  );
+
 export interface MusicService {
   generateToken(credentials: Credentials): Promise<AuthSuccess | AuthFailure>;
   login(authToken: string): Promise<MusicLibrary>;
@@ -104,4 +106,5 @@ export interface MusicLibrary {
   artist(id: string): Promise<Artist>;
   albums(q: AlbumQuery): Promise<Result<AlbumSummary>>;
   album(id: string): Promise<Album>;
+  genres(): Promise<string[]>;
 }

src/navidrome.ts

@@ -1,4 +1,6 @@
 import { option as O } from "fp-ts";
+import * as A from "fp-ts/Array";
+import { ordString } from "fp-ts/lib/Ord";
 import { pipe } from "fp-ts/lib/function";
 import { Md5 } from "ts-md5/dist/md5";
 import {
@@ -21,7 +23,6 @@ import axios from "axios";
 import { Encryption } from "./encryption";
 import randomString from "./random_string";
 
-
 export const t = (password: string, s: string) =>
   Md5.hashStr(`${password}${s}`);
 
@@ -75,6 +76,18 @@ export type GetAlbumListResponse = SubsonicResponse & {
   };
 };
 
+export type genre = {
+  _songCount: string;
+  _albumCount: string;
+  __text: string;
+};
+
+export type GenGenresResponse = SubsonicResponse & {
+  genres: {
+    genre: genre[];
+  };
+};
+
 export type SubsonicError = SubsonicResponse & {
   error: {
     _code: string;
@@ -115,13 +128,13 @@ export type IdName = {
 };
 
 export type getAlbumListParams = {
-  type: string,
+  type: string;
   size?: number;
   offet?: number;
-  fromYear?: string,
+  fromYear?: string;
-  toYear?: string,
+  toYear?: string;
-  genre?: string
+  genre?: string;
-}
+};
 
 const MAX_ALBUM_LIST = 500;
 
@@ -258,9 +271,14 @@ export class Navidrome implements MusicService {
       albums: (q: AlbumQuery): Promise<Result<AlbumSummary>> => {
         const p = pipe(
           O.fromNullable(q.genre),
-          O.map<string, getAlbumListParams>(genre => ({ type: "byGenre", genre })),
+          O.map<string, getAlbumListParams>((genre) => ({
-          O.getOrElse<getAlbumListParams>(() => ({ type: "alphabeticalByArtist" })),
+            type: "byGenre",
-        )
+            genre,
+          })),
+          O.getOrElse<getAlbumListParams>(() => ({
+            type: "alphabeticalByArtist",
+          }))
+        );
 
         return navidrome
           .get<GetAlbumListResponse>(credentials, "/rest/getAlbumList", {
@@ -286,6 +304,14 @@ export class Navidrome implements MusicService {
       album: (_: string): Promise<Album> => {
         return Promise.reject("not implemented");
       },
+      genres: () =>
+        navidrome
+          .get<GenGenresResponse>(credentials, "/rest/getGenres")
+          .then((it) => pipe(
+            it.genres.genre,
+            A.map(it => it.__text),
+            A.sort(ordString)
+          )),
     };
 
     return Promise.resolve(musicLibrary);

tests/in_memory_music_service.test.ts

@@ -346,7 +346,11 @@ describe("InMemoryMusicService", () => {
         describe("fetching all on one page", () => {
           it.only("should return all the albums of that genre for all the artists", async () => {
             expect(
-              await musicLibrary.albums({ _index: 0, _count: 100, genre: "Pop" })
+              await musicLibrary.albums({
+                _index: 0,
+                _count: 100,
+                genre: "Pop",
+              })
             ).toEqual({
               results: [
                 albumToAlbumSummary(artist1_album1),
@@ -394,7 +398,6 @@ describe("InMemoryMusicService", () => {
               });
             });
           });
- 
         });
 
         it("should return empty list if there are no albums for the genre", async () => {
@@ -411,5 +414,27 @@ describe("InMemoryMusicService", () => {
         });
       });
     });
+
+    describe("genres", () => {
+      const artist1 = anArtist({ albums: [anAlbum({ genre: "Pop" }),     anAlbum({ genre: "Rock" }), anAlbum({ genre: "Pop" })] });
+      const artist2 = anArtist({ albums: [anAlbum({ genre: "Hip-Hop" }), anAlbum({ genre: "Rap" }), anAlbum({ genre: "Pop" })] });
+
+      beforeEach(() => {
+        service.hasArtists(artist1, artist2);
+      });
+
+      describe("fetching all in one page", () => {
+        it("should provide an array of artists", async () => {
+          expect(
+            await musicLibrary.genres()
+          ).toEqual([
+            "Hip-Hop",
+            "Pop",
+            "Rap",
+            "Rock"
+          ]);
+        });
+      });
+    });
   });
 });

tests/in_memory_music_service.ts

@@ -1,5 +1,8 @@
 import { option as O } from "fp-ts";
+import * as A from "fp-ts/Array";
+import { eqString } from "fp-ts/lib/Eq";
 import { pipe } from "fp-ts/lib/function";
+import { ordString } from "fp-ts/lib/Ord";
 
 import {
   MusicService,
@@ -53,6 +56,7 @@ export class InMemoryMusicService implements MusicService {
     const credentials = JSON.parse(token) as Credentials;
     if (this.users[credentials.username] != credentials.password)
       return Promise.reject("Invalid auth token");
+
     return Promise.resolve({
       artists: (q: ArtistQuery) =>
         Promise.resolve(this.artists.map(artistToArtistSummary))
@@ -71,15 +75,9 @@ export class InMemoryMusicService implements MusicService {
             .flatMap((artist) => artist.albums.map((album) => [artist, album]))
             .filter(
               pipe(
-                pipe(
+                pipe(O.fromNullable(q.artistId), O.map(albumByArtist)),
-                  O.fromNullable(q.artistId), 
-                  O.map(albumByArtist)
-                ),
                 O.alt(() =>
-                  pipe(
+                  pipe(O.fromNullable(q.genre), O.map(albumWithGenre))
-                    O.fromNullable(q.genre), 
-                    O.map(albumWithGenre)
-                  )
                 ),
                 O.getOrElse(() => all)
               )
@@ -96,6 +94,18 @@ export class InMemoryMusicService implements MusicService {
           O.map((it) => Promise.resolve(it)),
           O.getOrElse(() => Promise.reject(`No album with id '${id}'`))
         ),
+      genres: () =>
+        Promise.resolve(
+          pipe(
+            this.artists,
+            A.map((it) => it.albums),
+            A.flatten,
+            A.map((it) => O.fromNullable(it.genre)),
+            A.compact,
+            A.uniq(eqString),
+            A.sort(ordString)
+          )
+        ),
     });
   }
 

tests/navidrome.test.ts

@@ -13,6 +13,8 @@ import {
   AuthSuccess,
   Images,
   albumToAlbumSummary,
+  range,
+  asArtistAlbumPairs,
 } from "../src/music_service";
 import { anAlbum, anArtist } from "./builders";
 
@@ -99,6 +101,17 @@ const artistXml = (
         </artist>
         </subsonic-response>`;
 
+const genresXml = (
+  genres: string[]
+) => `<subsonic-response xmlns="http://subsonic.org/restapi" status="ok" version="1.16.1" type="navidrome" serverVersion="0.40.0 (8799358a)">
+                                          <genres>
+                                            ${genres.map(
+                                              (it) =>
+                                                `<genre songCount="1475" albumCount="86">${it}</genre>`
+                                            )}
+                                          </genres>
+                                          </subsonic-response>`;
+
 const PING_OK = `<subsonic-response xmlns="http://subsonic.org/restapi" status="ok" version="1.16.1" type="navidrome" serverVersion="0.40.0 (8799358a)"></subsonic-response>`;
 
 describe("Navidrome", () => {
@@ -163,6 +176,31 @@ describe("Navidrome", () => {
     });
   });
 
+  describe("getting genres", () => {
+    const genres = ["HipHop", "Rap", "TripHop", "Pop", "Rock"];
+    beforeEach(() => {
+      mockGET
+        .mockImplementationOnce(() => Promise.resolve(ok(PING_OK)))
+        .mockImplementationOnce(() => Promise.resolve(ok(genresXml(genres))));
+    });
+
+    it.only("should return them alphabetically sorted", async () => {
+      const result = await navidrome
+        .generateToken({ username, password })
+        .then((it) => it as AuthSuccess)
+        .then((it) => navidrome.login(it.authToken))
+        .then((it) => it.genres());
+
+      expect(result).toEqual(genres.sort());
+
+      expect(axios.get).toHaveBeenCalledWith(`${url}/rest/getGenres`, {
+        params: {
+          ...authParams,
+        },
+      });
+    });
+  });
+
   describe("getting an artist", () => {
     const album1: Album = anAlbum();
 
@@ -386,27 +424,27 @@ describe("Navidrome", () => {
     });
   });
 
-  const range = (size: number) => [...Array(size).keys()];
-
-  const asArtistAlbumPairs = (artists: Artist[]): [Artist, Album][] =>
-    artists.flatMap((artist) =>
-      artist.albums.map((album) => [artist, album] as [Artist, Album])
-    );
-
   describe("getting albums", () => {
     describe("filtering", () => {
       const album1 = anAlbum({ genre: "Pop" });
       const album2 = anAlbum({ genre: "Rock" });
       const album3 = anAlbum({ genre: "Pop" });
 
-      const artist = anArtist({ albums: [album1, album2, album3]});
+      const artist = anArtist({ albums: [album1, album2, album3] });
 
       describe("by genre", () => {
         beforeEach(() => {
           mockGET
             .mockImplementationOnce(() => Promise.resolve(ok(PING_OK)))
             .mockImplementationOnce(() =>
-              Promise.resolve(ok(albumListXml([[artist, album1], [artist, album3]])))
+              Promise.resolve(
+                ok(
+                  albumListXml([
+                    [artist, album1],
+                    [artist, album3],
+                  ])
+                )
+              )
             );
         });
 
@@ -434,7 +472,6 @@ describe("Navidrome", () => {
           });
         });
       });
-  
     });
 
     describe("when there are less than 500 albums", () => {