feat: Add seekForward and seekBackward

Author: dyong1

lib/spotify-node-applescript.js

@@ -36,6 +36,10 @@ var scripts = {
         'tell application "Spotify" to next track',
     previous:
         'tell application "Spotify" to previous track',
+    seekForward:
+        'tell application "Spotify" to set player position to (player position + %s)',
+    seekBackward:
+        'tell application "Spotify" to set player position to (player position - %s)',
     jumpTo:
         'tell application "Spotify" to set player position to %s',
     isRunning:
@@ -151,6 +155,14 @@ exports.previous = function (callback) {
     return execScript('previous', callback);
 };
 
+exports.seekForward = function (seconds, callback) {
+    return execScript('seekForward', seconds, callback);
+};
+
+exports.seekBackward = function (seconds, callback) {
+    return execScript('seekBackward', seconds, callback);
+};
+
 exports.jumpTo = function (position, callback) {
     return execScript('jumpTo', position, callback);
 };

test/test.js

@@ -2,6 +2,7 @@ var spotify = require('../lib/spotify-node-applescript.js');
 var expect = require('chai').expect;
 
 var COLDPLAY_TROUBLE_ID = 'spotify:track:0R8P9KfGJCDULmlEoBagcO'
+var COLDPLAY_TROUBLE_PLAYTIME_SEC = 273
 
 describe('Spotify Controller', function () {
 
@@ -206,6 +207,60 @@ describe('Spotify Controller', function () {
         });
     });
 
+    // Seek forward and backward
+
+    it('should seek forward', function (done) {
+        // first do jumpTo 0 in case position is at the max
+        spotify.jumpTo(0, function () {
+            spotify.seekForward(5, function () {
+                spotify.getState(function (error, state) {
+                    expect(state.position).to.be.gte(5);
+                    done();
+                });
+            });
+        });
+    });
+
+    it('should seek backward', function (done) {
+        // first do jumpTo 15 in case position is at 0
+        spotify.jumpTo(15, function () {
+            spotify.seekBackward(5, function () {
+                spotify.getState(function (error, state) {
+                    expect(state.position).to.be.gte(10);
+                    done();
+                });
+            });
+        });
+    });
+
+    it('should set position to 0 on seeking foward exceeding max', function (done) {
+        // first do jumpTo to emulate overflow when seeking forward
+        spotify.jumpTo(COLDPLAY_TROUBLE_PLAYTIME_SEC - 3, function () {
+            spotify.getState(function (error, state) {
+                spotify.seekForward(5, function () {
+                    spotify.getState(function (error, state) {
+                        expect(state.position).to.equal(0);
+                        done();
+                    });
+                });
+            });
+        });
+    });
+
+    it('should set position to 0 on seeking foward exceeding min', function (done) {
+        // first do jumpTo to emulate overflow when seeking backward
+        spotify.jumpTo(2, function () {
+            spotify.getState(function (error, state) {
+                spotify.seekBackward(5, function () {
+                    spotify.getState(function (error, state) {
+                        expect(state.position).to.equal(0);
+                        done();
+                    });
+                });
+            });
+        });
+    });
+
     // State retrieval
 
     it('should return current track', function (done) {