Merge pull request #169 from hayribakici/code_cleanup_list

Refactors duplicate logic of `list` methods

lib/src/endpoints/albums.dart

@@ -19,13 +19,8 @@ class Albums extends EndpointPaging {
   }
 
   /// Returns album informations about a list of [albumIds]
-  Future<Iterable<Album>> list(Iterable<String> albumIds) async {
-    var jsonString = await _get('$_path?ids=${albumIds.join(',')}');
-    var map = json.decode(jsonString);
-
-    var artistsMap = map['albums'] as Iterable<dynamic>;
-    return artistsMap.map((m) => Album.fromJson(m));
-  }
+  Future<Iterable<Album>> list(List<String> albumIds) async => _listWithIds(
+      path: _path, ids: albumIds, jsonKey: 'albums', fromJson: Album.fromJson);
 
   /// Returns the tracks of a given [albumId]
   @Deprecated('Use [tracks] instead')

lib/src/endpoints/artists.dart

@@ -45,22 +45,17 @@ class Artists extends EndpointPaging {
       relatedArtists(artistId);
 
   /// Retrieves multiple artists with [artistIds]
-  Future<Iterable<Artist>> list(Iterable<String> artistIds) async {
-    var jsonString = await _api._get('$_path?ids=${artistIds.join(',')}');
-    var map = json.decode(jsonString);
-
-    var artistsMap = map['artists'] as Iterable<dynamic>;
-    return artistsMap.map((m) => Artist.fromJson(m));
-  }
+  Future<Iterable<Artist>> list(List<String> artistIds) async => _listWithIds(
+      path: _path,
+      ids: artistIds,
+      jsonKey: 'artists',
+      fromJson: Artist.fromJson);
 
   /// Returns related artists based on the artist with its [artistId]
-  Future<Iterable<Artist>> relatedArtists(String artistId) async {
-    var jsonString = await _api._get('$_path/$artistId/related-artists');
-    var map = json.decode(jsonString);
-
-    var artistsMap = map['artists'] as Iterable<dynamic>;
-    return artistsMap.map((m) => Artist.fromJson(m));
-  }
+  Future<Iterable<Artist>> relatedArtists(String artistId) async => _list(
+      path: '$_path/$artistId/related-artists',
+      jsonKey: 'artists',
+      fromJson: Artist.fromJson);
 
   /// [includeGroups] - A comma-separated list of keywords that will be used to
   /// filter the response. If not supplied, all album types will be returned.

lib/src/endpoints/audio_features.dart

@@ -19,11 +19,10 @@ class AudioFeatures extends EndpointBase {
   }
 
   /// Retrieve multiple audio features of tracks with [trackIds]
-  Future<Iterable<AudioFeature>> list(Iterable<String> trackIds) async {
-    var jsonString = await _api._get('$_path?ids=${trackIds.join(',')}');
-    var map = json.decode(jsonString);
-
-    var artistsMap = map['audio_features'] as Iterable<dynamic>;
-    return artistsMap.map((m) => AudioFeature.fromJson(m));
-  }
+  Future<Iterable<AudioFeature>> list(List<String> trackIds) async =>
+      _listWithIds(
+          path: _path,
+          ids: trackIds,
+          jsonKey: 'audio_features',
+          fromJson: AudioFeature.fromJson);
 }

lib/src/endpoints/endpoint_base.dart

@@ -29,4 +29,34 @@ abstract class EndpointBase {
           '${filteredQuery.keys.toList()[i]}=${filteredQuery.values.toList()[i]}',
     ).join('&');
   }
+
+  /// Generic method that requests a set of [T]'s with their given [ids].
+  Future<Iterable<T>> _listWithIds<T>(
+      {required String path,
+      required List<String> ids,
+      required String jsonKey,
+      required T Function(Map<String, dynamic>) fromJson,
+      Map<String, dynamic>? optionalParams}) async {
+    assert(ids.isNotEmpty, 'No id\'s were provided');
+
+    // filling the params
+    var params = <String, dynamic>{'ids': ids.join(',')};
+    params.addAll(optionalParams ?? {});
+
+    return _list(
+        path: '$path?${_buildQuery(params)}',
+        jsonKey: jsonKey,
+        fromJson: fromJson);
+  }
+
+  /// Generic method that converts requested json arrays into
+  /// [T] iterables with the given [toJson] function
+  Future<Iterable<T>> _list<T>(
+      {required String path,
+      required String jsonKey,
+      required T Function(Map<String, dynamic>) fromJson}) async {
+    var jsonString = await _api._get(path);
+    final tJson = jsonDecode(jsonString)[jsonKey] as Iterable<dynamic>;
+    return tJson.map((json) => fromJson(json));
+  }
 }

lib/src/endpoints/episodes.dart

@@ -12,19 +12,17 @@ class Episodes extends EndpointBase {
 
   Future<EpisodeFull> get(String id, [Market? market]) async {
     assert(id.isNotEmpty, 'No episode id was provided');
-    var jsonString = await _api
-        ._get('$_path/$id?' + _buildQuery({'market': market?.name}));
+    var jsonString =
+        await _api._get('$_path/$id?' + _buildQuery({'market': market?.name}));
     return EpisodeFull.fromJson(jsonDecode(jsonString));
   }
 
-  Future<Iterable<EpisodeFull>> list(List<String> ids, [Market? market]) async {
-    assert(ids.isNotEmpty, 'No episode id\'s were provided');
-    var jsonString = await _api._get('$_path?' +
-        _buildQuery({
-          'ids': ids.join(','),
-          'market': market?.name,
-        }));
-    var episodesJson = jsonDecode(jsonString)['episodes'] as Iterable<dynamic>;
-    return episodesJson.map((json) => EpisodeFull.fromJson(json));
-  }
+  Future<Iterable<EpisodeFull>> list(List<String> ids,
+          [Market? market]) async =>
+      _listWithIds(
+          path: _path,
+          ids: ids,
+          jsonKey: 'episodes',
+          fromJson: EpisodeFull.fromJson,
+          optionalParams: {'market': market?.name});
 }

lib/src/endpoints/shows.dart

@@ -31,13 +31,8 @@ class Shows extends EndpointPaging {
   }
 
   /// Get one or several shows
-  Future<Iterable<Show>> list(List<String> showsId) async {
-    final jsonString = await _get('$_path?ids=${showsId.join(',')}');
-    final map = json.decode(jsonString);
-
-    final showsMap = map['shows'] as Iterable<dynamic>;
-    return showsMap.map((m) => Show.fromJson(m));
-  }
+  Future<Iterable<Show>> list(List<String> showsId) async => _listWithIds(
+      path: _path, ids: showsId, jsonKey: 'shows', fromJson: Show.fromJson);
 
   /// Get a Show's Episodes
   ///

lib/src/endpoints/tracks.dart

@@ -23,12 +23,8 @@ class Tracks extends EndpointBase {
     return Track.fromJson(map);
   }
 
-  Future<Iterable<Track>> list(Iterable<String> trackIds) async {
-    final jsonString = await _api._get('$_path?ids=${trackIds.join(',')}');
-    final map = json.decode(jsonString);
-    final artistsMap = map['tracks'] as Iterable<dynamic>;
-    return artistsMap.map((m) => Track.fromJson(m));
-  }
+  Future<Iterable<Track>> list(List<String> trackIds) async => _listWithIds(
+      path: _path, ids: trackIds, jsonKey: 'tracks', fromJson: Track.fromJson);
 
   /// queries track batches of size [queryLimit] from [trackIds] and yields Track object Iterables
   Stream<Iterable<Track>> listInBatches(Iterable<String> trackIds,

test/data/v1/artists/0TnOYISbd1XYRBk9myaseg/related-artists.json

@@ -0,0 +1,42 @@
+{
+  "artists": [
+    {
+      "external_urls": {
+        "spotify": "https://open.spotify.com/artist/0jnsk9HBra6NMjO2oANoPY"
+      },
+      "followers": {
+        "href": null,
+        "total": 8953912
+      },
+      "genres": [
+        "dance pop",
+        "miami hip hop",
+        "pop",
+        "pop rap"
+      ],
+      "href": "https://api.spotify.com/v1/artists/0jnsk9HBra6NMjO2oANoPY",
+      "id": "0jnsk9HBra6NMjO2oANoPY",
+      "images": [
+        {
+          "height": 640,
+          "url": "https://i.scdn.co/image/ab6761610000e5eb655ca8f3196953554b479452",
+          "width": 640
+        },
+        {
+          "height": 320,
+          "url": "https://i.scdn.co/image/ab67616100005174655ca8f3196953554b479452",
+          "width": 320
+        },
+        {
+          "height": 160,
+          "url": "https://i.scdn.co/image/ab6761610000f178655ca8f3196953554b479452",
+          "width": 160
+        }
+      ],
+      "name": "Flo Rida",
+      "popularity": 77,
+      "type": "artist",
+      "uri": "spotify:artist:0jnsk9HBra6NMjO2oANoPY"
+    }
+  ]
+}

test/spotify_test.dart

@@ -133,6 +133,16 @@ Future main() async {
       expect(artists.length, 2);
     });
 
+    test('getRelatedArtists', () async {
+      var relatedArtists =
+          await spotify.artists.relatedArtists('0TnOYISbd1XYRBk9myaseg');
+      var first = relatedArtists.first;
+      expect(first.id, '0jnsk9HBra6NMjO2oANoPY');
+      expect(first.href,
+          'https://api.spotify.com/v1/artists/0jnsk9HBra6NMjO2oANoPY');
+      expect(first.name, 'Flo Rida');
+    });
+
     test('getError', () async {
       spotify.mockHttpErrors =
           [MockHttpError(statusCode: 401, message: 'Bad Request')].iterator;