added "add song to queue" method (#302)

* added add song to queue

* updated readme with new feature

* Minor changes

Make minor changes in method and argument names.

Co-authored-by: thelinmichael <[email protected]>

Author: thattomperson

__tests__/spotify-web-api.js

@@ -1788,6 +1788,31 @@ describe('Spotify Web API', () => {
     });
   });
 
+  test("should add songs to the user's queue:", done => {
+    sinon.stub(HttpManager, '_makeRequest', function(
+      method,
+      options,
+      uri,
+      callback
+    ) {
+      expect(method).toBe(superagent.post);
+      expect(uri).toBe('https://api.spotify.com/v1/me/player/queue');
+      expect(options.query).toEqual({
+        uri: 'spotify:track:2jpDioAB9tlYXMdXDK3BGl'
+      });
+      expect(options.headers).toEqual({
+        Authorization: 'Bearer someAccessToken'
+      });
+      callback(null, null);
+    });
+
+    var api = new SpotifyWebApi({
+      accessToken: 'someAccessToken'
+    });
+
+    api.addToQueue('spotify:track:2jpDioAB9tlYXMdXDK3BGl').then(done);
+  });
+
   test("should get user's devices:", done => {
     sinon.stub(HttpManager, '_makeRequest').callsFake(function(
       method,

src/spotify-web-api.js

@@ -1029,6 +1029,28 @@ SpotifyWebApi.prototype = {
   },
 
   /**
+
+   * Add track or episode to device queue
+   * @param {string} [uri] uri of the track or episode to add
+   * @param {Object} [options] Options, being device_id.
+   * @param {requestCallback} [callback] Optional callback method to be called instead of the promise.
+   * @returns {Promise|undefined} A promise that if successful, resolves into a paging object of tracks,
+   *          otherwise an error. Not returned if a callback is given.
+   */
+  addToQueue: function(uri, options, callback) {
+    return WebApiRequest.builder(this.getAccessToken())
+      .withPath('/v1/me/player/queue')
+      .withQueryParameters(
+        {
+          uri: uri
+        },
+        options
+      )
+      .build()
+      .execute(HttpManager.post, callback);
+  },
+
+
    * Get the Current User's Available Devices
    * @param {requestCallback} [callback] Optional callback method to be called instead of the promise.
    * @returns {Promise|undefined} A promise that if successful, resolves into an array of device objects,