Add support for "Get a Playlist Cover Image" endpoint - Fixes #162 (#163)

Author: JMPerez

__test__/fixtures.js

@@ -44,6 +44,7 @@ module.exports = {
   user_top_tracks: loadFixture('user_top_tracks'),
   playlist: loadFixture('playlist'),
   playlist_tracks: loadFixture('playlist_tracks'),
+  playlist_cover_image: loadFixture('playlist_cover_image'),
   featured_playlists: loadFixture('featured_playlists'),
   browse_categories: loadFixture('browse_categories'),
   category: loadFixture('category'),

__test__/fixtures/playlist_cover_image.json

@@ -0,0 +1,7 @@
+[
+  {
+    "height": 640,
+    "url": "https://u.scdn.co/images/pl/default/438f9b65ac4eb48681351593142daeb070986293",
+    "width": 640
+  }
+]

__test__/spotify-web-api.spec.js

@@ -873,6 +873,25 @@ describe('Basic tests', function () {
       );
     });
 
+    it('should get cover image of a playlist', function () {
+      var callback = sinon.spy();
+      var api = new SpotifyWebApi();
+      api.setAccessToken('<example_access_token>');
+      api.getPlaylistCoverImage('3cEYpjA9oz9GiPac4AsH4n', callback);
+      that.requests[0].respond(
+        200,
+        { 'Content-Type': 'application/json' },
+        JSON.stringify(fixtures.playlist_cover_image)
+      );
+      expect(
+        callback.calledWith(null, fixtures.playlist_cover_image)
+      ).toBeTruthy();
+      expect(that.requests.length).toBe(1);
+      expect(that.requests[0].url).toBe(
+        'https://api.spotify.com/v1/playlists/3cEYpjA9oz9GiPac4AsH4n/images'
+      );
+    });
+
     it('should create a playlist', function () {
       var callback = sinon.spy();
       var api = new SpotifyWebApi();

src/spotify-web-api.js

@@ -759,6 +759,24 @@ var SpotifyWebApi = (function () {
     return _checkParamsAndPerformRequest(requestData, options, callback);
   };
 
+  /**
+   * Gets the current image associated with a specific playlist.
+   * See [Get a Playlist Cover Image](https://developer.spotify.com/documentation/web-api/reference/playlists/get-playlist-cover/) on
+   * the Spotify Developer site for more information about the endpoint.
+   *
+   * @param {string} playlistId The id of the playlist. If you know the Spotify URI it is easy
+   * to find the playlist id (e.g. spotify:playlist:<here_is_the_playlist_id>)
+   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
+   * one is the error object (null if no error), and the second is the value if the request succeeded.
+   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
+   */
+  Constr.prototype.getPlaylistCoverImage = function (playlistId, callback) {
+    var requestData = {
+      url: _baseUri + '/playlists/' + playlistId + '/images'
+    };
+    return _checkParamsAndPerformRequest(requestData, callback);
+  };
+
   /**
    * Creates a playlist and stores it in the current user's library.
    * See [Create a Playlist](https://developer.spotify.com/web-api/create-playlist/) on

src/typings/spotify-api.d.ts

@@ -706,6 +706,13 @@ declare namespace SpotifyApi {
    */
   interface UploadCustomPlaylistCoverImageResponse extends VoidResponse {}
 
+  /**
+   * Get a Playlist Cover Image
+   * GET /v1/playlists/{playlist_id}/images
+   * https://developer.spotify.com/documentation/web-api/reference/playlists/get-playlist-cover/
+   */
+  interface PlaylistCoverImageResponse extends Array<ImageObject> {}
+
   /**
    * Check if Users Follow a Playlist
    *

src/typings/spotify-web-api.d.ts

@@ -502,6 +502,22 @@ declare namespace SpotifyWebApi {
       callback?: ResultsCallback<SpotifyApi.PlaylistTrackResponse>
     ): Promise<SpotifyApi.PlaylistTrackResponse>;
 
+    /**
+     * Gets the current image associated with a specific playlist.
+     * See [Get a Playlist Cover Image](https://developer.spotify.com/documentation/web-api/reference/playlists/get-playlist-cover/) on
+     * the Spotify Developer site for more information about the endpoint.
+     *
+     * @param {string} playlistId The id of the playlist. If you know the Spotify URI it is easy
+     * to find the playlist id (e.g. spotify:playlist:<here_is_the_playlist_id>)
+     * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
+     * one is the error object (null if no error), and the second is the value if the request succeeded.
+     * @return {Object} Null if a callback is provided, a `Promise` object otherwise
+     */
+    getPlaylistCoverImage(
+      playlistId: string,
+      callback?: ResultsCallback<SpotifyApi.PlaylistCoverImageResponse>
+    ): Promise<SpotifyApi.PlaylistCoverImageResponse>;
+
     /**
      * Creates a playlist and stores it in the current user's library.
      * See [Create a Playlist](https://developer.spotify.com/web-api/create-playlist/) on