diff --git a/js/app/controllers/maincontroller.js b/js/app/controllers/maincontroller.js
index f7319e73c..5636e6280 100644
--- a/js/app/controllers/maincontroller.js
+++ b/js/app/controllers/maincontroller.js
@@ -263,7 +263,7 @@ function ($rootScope, $scope, $timeout, $window, $document, ArtistFactory,
 		});
 	}
 
-	$scope.startScanning = function(fileIds /*optional*/) {
+	$scope.startScanning = function(fileIds = null) {
 		if (fileIds) {
 			filesToScan = fileIds;
 			previouslyScannedCount = 0;
@@ -356,14 +356,11 @@ function ($rootScope, $scope, $timeout, $window, $document, ArtistFactory,
 		return offset;
 	}
 
-	$scope.scrollToItem = function(itemId, animationTime /* optional */) {
+	$scope.scrollToItem = function(itemId, animationTime = 500) {
 		if (itemId) {
 			let container = OCA.Music.Utils.getScrollContainer();
 			let element = $('#' + itemId);
 			if (container && element) {
-				if (animationTime === undefined) {
-					animationTime = 500;
-				}
 				container.scrollToElement(element, scrollOffset(), animationTime);
 			}
 		}
@@ -376,12 +373,12 @@ function ($rootScope, $scope, $timeout, $window, $document, ArtistFactory,
 	// Navigate to a view selected from the navigation bar
 	let navigationDestination = null;
 	let afterNavigationCallback = null;
-	$scope.navigateTo = function(destination, callback /*optional*/) {
+	$scope.navigateTo = function(destination, callback = null) {
 		let curView = $rootScope.currentView;
 		if (curView != destination) {
 			$rootScope.currentView = null;
 			navigationDestination = destination;
-			afterNavigationCallback = callback || null;
+			afterNavigationCallback = callback;
 			$rootScope.loading = true;
 			// Deactivate the current view. The view emits 'viewDeactivated' once that is done.
 			// In the abnormal special case of no active view, activate the new view immediately.
@@ -402,10 +399,7 @@ function ($rootScope, $scope, $timeout, $window, $document, ArtistFactory,
 
 	// Compact/normal layout of the Albums view
 	$scope.albumsCompactLayout = (localStorage.getItem('oc_music_albums_compact') === 'true');
-	$scope.toggleAlbumsCompactLayout = function(useCompact /*optional, invert current value if omitted */) {
-		if (typeof useCompact === 'undefined') {
-			useCompact = !$scope.albumsCompactLayout;
-		}
+	$scope.toggleAlbumsCompactLayout = function(useCompact = !$scope.albumsCompactLayout) {
 		$scope.albumsCompactLayout = useCompact;
 		$('#albums').toggleClass('compact', useCompact);
 		$rootScope.$emit('albumsLayoutChanged');
@@ -418,10 +412,7 @@ function ($rootScope, $scope, $timeout, $window, $document, ArtistFactory,
 
 	// Flat/tree layout of the Folders view
 	$scope.foldersFlatLayout = (localStorage.getItem('oc_music_folders_flat') === 'true');
-	$scope.toggleFoldersFlatLayout = function(useFlat /*optional, invert current value if omitted */) {
-		if (typeof useFlat === 'undefined') {
-			useFlat = !$scope.foldersFlatLayout;
-		}
+	$scope.toggleFoldersFlatLayout = function(useFlat = !$scope.foldersFlatLayout) {
 		$scope.foldersFlatLayout = useFlat;
 		$rootScope.$emit('foldersLayoutChanged');
 
diff --git a/js/app/controllers/playercontroller.js b/js/app/controllers/playercontroller.js
index 5ac68c9d5..3d0fbfafe 100644
--- a/js/app/controllers/playercontroller.js
+++ b/js/app/controllers/playercontroller.js
@@ -7,7 +7,7 @@
  * @author Morris Jobke <hey@morrisjobke.de>
  * @author Pauli Järvinen <pauli.jarvinen@gmail.com>
  * @copyright Morris Jobke 2013
- * @copyright Pauli Järvinen 2017 - 2022
+ * @copyright Pauli Järvinen 2017 - 2023
  */
 
 import radioIconPath from '../../../img/radio-file.svg';
@@ -208,8 +208,7 @@ function ($scope, $rootScope, playlistService, Audio, gettextCatalog, Restangula
 		}
 	}
 
-	function getRadioTitle(radioTrack, failCounter /*optional, internal*/) {
-		failCounter = failCounter || 0;
+	function getRadioTitle(radioTrack, failCounter = 0 /*internal*/) {
 		abortRadioTitleFetch = $q.defer();
 		const config = {timeout: abortRadioTitleFetch.promise};
 		const metaType = radioTrack.metadata?.type; // request the same metadata type as previously got (if any)
@@ -259,7 +258,7 @@ function ($scope, $rootScope, playlistService, Audio, gettextCatalog, Restangula
 		return null;
 	}
 
-	function setCurrentTrack(playlistEntry, startOffset /*optional*/, gapless /*optional*/) {
+	function setCurrentTrack(playlistEntry, startOffset = 0, gapless = false) {
 		let track = playlistEntry ? playlistEntry.track : null;
 
 		if (track !== null) {
@@ -276,7 +275,7 @@ function ($scope, $rootScope, playlistService, Audio, gettextCatalog, Restangula
 		$scope.shiftHeldDown = false;
 	}
 
-	function playCurrentTrack(startOffset /*optional*/) {
+	function playCurrentTrack(startOffset = 0) {
 		// the playback may have been stopped and currentTrack vanished during the debounce time
 		if ($scope.currentTrack) {
 			if ($scope.currentTrack.type === 'radio') {
@@ -318,7 +317,7 @@ function ($scope, $rootScope, playlistService, Audio, gettextCatalog, Restangula
 	 */
 	let debouncedPlayCurrentTrack = _.debounce(playCurrentTrack, 300);
 
-	function playTrack(track, startOffset /*optional*/, gapless /*optional*/) {
+	function playTrack(track, startOffset = 0, gapless = false) {
 		$scope.currentTrack = track;
 
 		// Don't indicate support for seeking before we actually know its status for the new track.
@@ -509,7 +508,7 @@ function ($scope, $rootScope, playlistService, Audio, gettextCatalog, Restangula
 		$timeout(() => $scope.playPauseContextMenuVisible = false);
 	});
 
-	$scope.next = function(startOffset /*optional*/, gapless /*optional*/) {
+	$scope.next = function(startOffset = 0, gapless = false) {
 		let entry = playlistService.jumpToNextTrack();
 
 		// For ordinary tracks, skip the tracks with unsupported MIME types.
@@ -613,7 +612,7 @@ function ($scope, $rootScope, playlistService, Audio, gettextCatalog, Restangula
 
 	$scope.seekForward = $scope.player.seekForward;
 
-	playlistService.subscribe('play', function(_event, _playingView /*optional, ignored*/, startOffset /*optional*/) {
+	playlistService.subscribe('play', function(_event, _playingView = null, startOffset = 0) {
 		$scope.next(startOffset); /* fetch track and start playing*/
 	});
 
diff --git a/js/app/controllers/views/alltracksviewcontroller.js b/js/app/controllers/views/alltracksviewcontroller.js
index 96f0e4823..31dbc97ac 100644
--- a/js/app/controllers/views/alltracksviewcontroller.js
+++ b/js/app/controllers/views/alltracksviewcontroller.js
@@ -5,7 +5,7 @@
  * later. See the COPYING file.
  *
  * @author Pauli Järvinen <pauli.jarvinen@gmail.com>
- * @copyright Pauli Järvinen 2018 - 2022
+ * @copyright Pauli Järvinen 2018 - 2023
  */
 
 
@@ -35,7 +35,7 @@ angular.module('Music').controller('AllTracksViewController', [
 			_.each(_unsubFuncs, function(func) { func(); });
 		});
 
-		function play(startIndex /*optional*/) {
+		function play(startIndex = 0) {
 			playlistService.setPlaylist('alltracks', _tracks, startIndex);
 			playlistService.publish('play');
 		}
diff --git a/js/app/controllers/views/foldersviewcontroller.js b/js/app/controllers/views/foldersviewcontroller.js
index d846c8f84..3121351a3 100644
--- a/js/app/controllers/views/foldersviewcontroller.js
+++ b/js/app/controllers/views/foldersviewcontroller.js
@@ -5,7 +5,7 @@
  * later. See the COPYING file.
  *
  * @author Pauli Järvinen <pauli.jarvinen@gmail.com>
- * @copyright Pauli Järvinen 2019 - 2022
+ * @copyright Pauli Järvinen 2019 - 2023
  */
 
 
@@ -30,10 +30,10 @@ angular.module('Music').controller('FoldersViewController', [
 			unsubFuncs.push( $rootScope.$on(event, handler) );
 		}
 
-		function playPlaylist(listId, tracks, startFromTrackId /*optional*/) {
+		function playPlaylist(listId, tracks, startFromTrackId = undefined) {
 			let startIndex = null;
 			if (startFromTrackId !== undefined) {
-				startIndex = _.findIndex(tracks, function(i) {return i.track.id == startFromTrackId;});
+				startIndex = _.findIndex(tracks, (i) => i.track.id == startFromTrackId);
 			}
 			playlistService.setPlaylist(listId, tracks, startIndex);
 			playlistService.publish('play');
diff --git a/js/app/controllers/views/genresviewcontroller.js b/js/app/controllers/views/genresviewcontroller.js
index aacca3590..0de944dc4 100644
--- a/js/app/controllers/views/genresviewcontroller.js
+++ b/js/app/controllers/views/genresviewcontroller.js
@@ -5,7 +5,7 @@
  * later. See the COPYING file.
  *
  * @author Pauli Järvinen <pauli.jarvinen@gmail.com>
- * @copyright Pauli Järvinen 2020, 2021
+ * @copyright Pauli Järvinen 2020 - 2023
  */
 
 
@@ -34,10 +34,10 @@ angular.module('Music').controller('GenresViewController', [
 			$scope.$parent.filesWithUnscannedGenre = null;
 		};
 
-		function playPlaylist(listId, tracks, startFromTrackId /*optional*/) {
+		function playPlaylist(listId, tracks, startFromTrackId = undefined) {
 			let startIndex = null;
 			if (startFromTrackId !== undefined) {
-				startIndex = _.findIndex(tracks, function(i) {return i.track.id == startFromTrackId;});
+				startIndex = _.findIndex(tracks, (i) => i.track.id == startFromTrackId);
 			}
 			playlistService.setPlaylist(listId, tracks, startIndex);
 			playlistService.publish('play');
diff --git a/js/app/controllers/views/playlistviewcontroller.js b/js/app/controllers/views/playlistviewcontroller.js
index 5a2b76511..ed379f75a 100644
--- a/js/app/controllers/views/playlistviewcontroller.js
+++ b/js/app/controllers/views/playlistviewcontroller.js
@@ -7,7 +7,7 @@
  * @author Morris Jobke <hey@morrisjobke.de>
  * @author Pauli Järvinen <pauli.jarvinen@gmail.com>
  * @copyright Morris Jobke 2013
- * @copyright Pauli Järvinen 2017 - 2021
+ * @copyright Pauli Järvinen 2017 - 2023
  */
 
 
@@ -58,7 +58,7 @@ angular.module('Music').controller('PlaylistViewController', [
 			});
 		};
 
-		function play(startIndex /*optional*/) {
+		function play(startIndex = 0) {
 			let id = 'playlist-' + $scope.playlist.id;
 			playlistService.setPlaylist(id, $scope.tracks, startIndex);
 			playlistService.publish('play');
diff --git a/js/app/controllers/views/podcastsviewcontroller.js b/js/app/controllers/views/podcastsviewcontroller.js
index a68343acb..1d330f76a 100644
--- a/js/app/controllers/views/podcastsviewcontroller.js
+++ b/js/app/controllers/views/podcastsviewcontroller.js
@@ -5,7 +5,7 @@
  * later. See the COPYING file.
  *
  * @author Pauli Järvinen <pauli.jarvinen@gmail.com>
- * @copyright Pauli Järvinen 2021, 2022
+ * @copyright Pauli Järvinen 2021 - 2023
  */
 
 angular.module('Music').controller('PodcastsViewController', [
@@ -122,14 +122,14 @@ angular.module('Music').controller('PodcastsViewController', [
 			updateHighlight(playlistId);
 		});
 
-		subscribe('scrollToPodcastEpisode', function(_event, episodeId, animationTime /* optional */) {
+		subscribe('scrollToPodcastEpisode', function(_event, episodeId, animationTime = 500) {
 			let episode = libraryService.getPodcastEpisode(episodeId);
 			if (episode) {
 				$scope.$parent.scrollToItem('podcast-channel-' + episode.channel.id, animationTime);
 			}
 		});
 
-		subscribe('scrollToPodcastChannel', function(_event, channelId, animationTime /* optional */) {
+		subscribe('scrollToPodcastChannel', function(_event, channelId, animationTime = 500) {
 			$scope.$parent.scrollToItem('podcast-channel-' + channelId, animationTime);
 		});
 
diff --git a/js/app/controllers/views/radioviewcontroller.js b/js/app/controllers/views/radioviewcontroller.js
index 9d4ab6f33..bd5c665a4 100644
--- a/js/app/controllers/views/radioviewcontroller.js
+++ b/js/app/controllers/views/radioviewcontroller.js
@@ -5,7 +5,7 @@
  * later. See the COPYING file.
  *
  * @author Pauli Järvinen <pauli.jarvinen@gmail.com>
- * @copyright Pauli Järvinen 2020, 2021
+ * @copyright Pauli Järvinen 2020 - 2023
  */
 
 
@@ -75,7 +75,7 @@ angular.module('Music').controller('RadioViewController', [
 			);
 		}
 
-		function play(startIndex /*optional*/) {
+		function play(startIndex = 0) {
 			playlistService.setPlaylist('radio', $scope.stations, startIndex);
 			playlistService.publish('play');
 		}
diff --git a/js/app/directives/albumart.js b/js/app/directives/albumart.js
index 644c92385..c0b6fa258 100644
--- a/js/app/directives/albumart.js
+++ b/js/app/directives/albumart.js
@@ -7,7 +7,7 @@
  * @author Morris Jobke <hey@morrisjobke.de>
  * @author Pauli Järvinen <pauli.jarvinen@gmail.com>
  * @copyright 2013 Morris Jobke
- * @copyright 2016 - 2022 Pauli Järvinen
+ * @copyright 2016 - 2023 Pauli Järvinen
  *
  */
 
@@ -21,12 +21,12 @@ angular.module('Music').directive('albumart', [function() {
 		element.css('background-image', 'url(' + imageUrl + ')');
 	}
 
-	function setPlaceholder(element, text, seed /*optional*/) {
+	function setPlaceholder(element, text, seed = null) {
 		if (text) {
 			// remove background image
 			element.css('background-image', '');
 			// add placeholder stuff
-			element.imageplaceholder(seed || text, text);
+			element.imageplaceholder(seed ?? text, text);
 			// remove inlined size-related style properties set by imageplaceholder() to allow
 			// dynamic changing between mobile and desktop styles when window size changes
 			element.css('line-height', '');
diff --git a/js/app/directives/inviewobserver.js b/js/app/directives/inviewobserver.js
index 0189770fa..bbfde0619 100644
--- a/js/app/directives/inviewobserver.js
+++ b/js/app/directives/inviewobserver.js
@@ -5,7 +5,7 @@
  * later. See the COPYING file.
  *
  * @author Pauli Järvinen <pauli.jarvinen@gmail.com>
- * @copyright 2019 - 2022 Pauli Järvinen
+ * @copyright 2019 - 2023 Pauli Järvinen
  *
  */
 
@@ -117,7 +117,7 @@ function($rootScope, $timeout, inViewService) {
 	/**
 	 * Initial setup of the in-view-port statuses of the available instances
 	 */
-	function initInViewRange(skipDelays/*optional*/) {
+	function initInViewRange(skipDelays = false) {
 		let length = _instances.length;
 		let i;
 
@@ -204,7 +204,7 @@ function($rootScope, $timeout, inViewService) {
 	/**
 	 * Update in-view-port status of the given instance
 	 */
-	function updateInViewStatus(inst, skipDelays/*optional*/) {
+	function updateInViewStatus(inst, skipDelays = false) {
 		skipDelays = skipDelays || false;
 
 		let wasInViewPort = inst.inViewPort;
@@ -285,7 +285,7 @@ function($rootScope, $timeout, inViewService) {
 		invalidateInViewRange();
 	}
 
-	function updateStatusForAll(skipDelays/*optional*/) {
+	function updateStatusForAll(skipDelays = false) {
 		_(_instances).each(function(inst) {
 			updateInViewStatus(inst, skipDelays);
 		});
diff --git a/js/app/directives/tracklist.js b/js/app/directives/tracklist.js
index edcddbd97..b75950b7f 100755
--- a/js/app/directives/tracklist.js
+++ b/js/app/directives/tracklist.js
@@ -7,7 +7,7 @@
  * @author Moritz Meißelbach <moritz@meisselba.ch>
  * @author Pauli Järvinen <pauli.jarvinen@gmail.com>
  * @copyright 2017 Moritz Meißelbach
- * @copyright 2018 - 2021 Pauli Järvinen
+ * @copyright 2018 - 2023 Pauli Järvinen
  *
  */
 
@@ -151,7 +151,7 @@ function ($rootScope, $interpolate, gettextCatalog) {
 		 * @param string className (optional)
 		 * @returns {HTMLLIElement}
 		 */
-		function getTrackNode(track, index, className) {
+		function getTrackNode(track, index, className = null) {
 			let listItem = document.createElement('li');
 
 			let listItemContent = document.createElement('div');
diff --git a/js/app/services/inviewservice.js b/js/app/services/inviewservice.js
index 895ac828a..1e0c9f843 100644
--- a/js/app/services/inviewservice.js
+++ b/js/app/services/inviewservice.js
@@ -5,7 +5,7 @@
  * later. See the COPYING file.
  *
  * @author Pauli Järvinen <pauli.jarvinen@gmail.com>
- * @copyright 2019 Pauli Järvinen
+ * @copyright 2019 - 2023 Pauli Järvinen
  *
  */
 
@@ -38,11 +38,8 @@ angular.module('Music').service('inViewService', ['$rootScope', function($rootSc
 		 * @param int topMargin Optional top extension in pixels (use negative value for reduction)
 		 * @param int bottomMargin Optional bottom extension in pixels (use negative value for reduction)
 		 */
-		isElementInViewPort: function(el, topMargin/*optional*/, bottomMargin/*optional*/) {
+		isElementInViewPort: function(el, topMargin = 0, bottomMargin = 0) {
 			if (el) {
-				topMargin = topMargin || 0;
-				bottomMargin = bottomMargin || 0;
-
 				if (dirty) {
 					updateHeights();
 				}
diff --git a/js/app/services/libraryservice.js b/js/app/services/libraryservice.js
index 80e24e9e0..d63e6effd 100644
--- a/js/app/services/libraryservice.js
+++ b/js/app/services/libraryservice.js
@@ -220,9 +220,7 @@ angular.module('Music').service('libraryService', [function() {
 		});
 	}
 
-	function search(container, fields, query, maxResults/*optional*/) {
-		maxResults = maxResults || Infinity;
-
+	function search(container, fields, query, maxResults) {
 		query = foldString(query);
 		// In case the query contains many words separated with whitespace, each part
 		// has to be found but the whitespace is disregarded.
@@ -555,41 +553,41 @@ angular.module('Music').service('libraryService', [function() {
 		podcastsLoaded: function() {
 			return podcastChannels !== null;
 		},
-		searchTracks: function(query, maxResults/*optional*/) {
+		searchTracks: function(query, maxResults = Infinity) {
 			return search(tracksIndex, ['title', 'artistName'], query, maxResults);
 		},
-		searchTracksInAlbums: function(query, maxResults/*optional*/) {
+		searchTracksInAlbums: function(query, maxResults = Infinity) {
 			return search(
 					tracksIndex,
 					['title', 'artistName', 'album.name', 'album.year', 'album.artist.name'],
 					query,
 					maxResults);
 		},
-		searchTracksInFolders: function(query, maxResults/*optional*/) {
+		searchTracksInFolders: function(query, maxResults = Infinity) {
 			return search(
 					tracksIndex,
 					['title', 'artistName', 'folder.path'],
 					query,
 					maxResults);
 		},
-		searchTracksInGenres: function(query, maxResults/*optional*/) {
+		searchTracksInGenres: function(query, maxResults = Infinity) {
 			return search(
 					tracksIndex,
 					['title', 'artistName', 'genre.name'],
 					query,
 					maxResults);
 		},
-		searchTracksInPlaylist: function(playlistId, query, maxResults/*optional*/) {
+		searchTracksInPlaylist: function(playlistId, query, maxResults = Infinity) {
 			let list = this.getPlaylist(playlistId) || [];
 			list = _.map(list.tracks, 'track');
 			list = _.uniq(list);
 			return search(list, ['title', 'artistName'], query, maxResults);
 		},
-		searchRadioStations: function(query, maxResults/*optional*/) {
+		searchRadioStations: function(query, maxResults = Infinity) {
 			let stations = _.map(radioStations, 'track');
 			return search(stations, ['name', 'stream_url'], query, maxResults);
 		},
-		searchPodcasts: function(query, maxResults/*optional*/) {
+		searchPodcasts: function(query, maxResults = Infinity) {
 			let episodes = _(podcastChannels).map('episodes').flatten().value();
 			return search(episodes, ['title', 'channel.title'], query, maxResults);
 		},
diff --git a/js/app/services/playlistfileservice.js b/js/app/services/playlistfileservice.js
index 472d8392f..17712800d 100644
--- a/js/app/services/playlistfileservice.js
+++ b/js/app/services/playlistfileservice.js
@@ -5,7 +5,7 @@
  * later. See the COPYING file.
  *
  * @author Pauli Järvinen <pauli.jarvinen@gmail.com>
- * @copyright Pauli Järvinen 2021
+ * @copyright Pauli Järvinen 2021 - 2023
  */
 
 angular.module('Music').service('playlistFileService', [
@@ -75,9 +75,9 @@ function($rootScope, $q, libraryService, gettextCatalog, Restangular) {
 		// Export playlist to file
 		exportPlaylist: function(playlist) {
 
-			function onFolderSelected(path, onCollision /*optional*/) {
+			function onFolderSelected(path, onCollision = 'abort') {
 				playlist.busy = true;
-				let args = { path: path, oncollision: onCollision || 'abort' };
+				let args = { path: path, oncollision: onCollision };
 				Restangular.one('playlists', playlist.id).all('export').post(args).then(
 					function (result) {
 						OC.Notification.showTemporary(
@@ -103,9 +103,9 @@ function($rootScope, $q, libraryService, gettextCatalog, Restangular) {
 			let deferred = $q.defer();
 			let name = gettextCatalog.getString('Internet radio');
 
-			function onFolderSelected(path, onCollision /*optional*/) {
+			function onFolderSelected(path, onCollision = 'abort') {
 				deferred.notify('started');
-				let args = { path: path, name: name, oncollision: onCollision || 'abort' };
+				let args = { path: path, name: name, oncollision: onCollision };
 				Restangular.all('radio/export').post(args).then(
 					function (result) {
 						OC.Notification.showTemporary(
diff --git a/js/app/services/playlistservice.js b/js/app/services/playlistservice.js
index 74b05b223..e982d0b12 100644
--- a/js/app/services/playlistservice.js
+++ b/js/app/services/playlistservice.js
@@ -7,7 +7,7 @@
  * @author Morris Jobke <hey@morrisjobke.de>
  * @author Pauli Järvinen <pauli.jarvinen@gmail.com>
  * @copyright Morris Jobke 2013
- * @copyright Pauli Järvinen 2017 - 2022
+ * @copyright Pauli Järvinen 2017 - 2023
  */
 
 angular.module('Music').service('playlistService', ['$rootScope', function($rootScope) {
@@ -139,9 +139,9 @@ angular.module('Music').service('playlistService', ['$rootScope', function($root
 				return playlist[playOrder[playOrderIter + 1]];
 			}
 		},
-		setPlaylist: function(listId, pl, startIndex /*optional*/) {
+		setPlaylist: function(listId, pl, startIndex = null) {
 			playlist = pl.slice(); // copy
-			startFromIndex = (startIndex === undefined) ? null : startIndex;
+			startFromIndex = startIndex;
 			if (listId === playlistId) {
 				// preserve the history if list wasn't actually changed
 				dropFuturePlayOrder();
diff --git a/js/embedded/embeddedplayer.js b/js/embedded/embeddedplayer.js
index f74551c9a..cf4f7511d 100644
--- a/js/embedded/embeddedplayer.js
+++ b/js/embedded/embeddedplayer.js
@@ -5,7 +5,7 @@
  * later. See the COPYING file.
  *
  * @author Pauli Järvinen <pauli.jarvinen@gmail.com>
- * @copyright Pauli Järvinen 2017 - 2022
+ * @copyright Pauli Järvinen 2017 - 2023
  */
 
 import playIconPath from '../../img/play-big.svg';
@@ -571,7 +571,7 @@ OCA.Music.EmbeddedPlayer = function(onClose, onNext, onPrev, onMenuOpen, onShowL
 		updateMediaSession(data);
 	}
 
-	function loadFileInfoFromUrl(url, fallbackTitle, fileId, callback /*optional*/) {
+	function loadFileInfoFromUrl(url, fallbackTitle, fileId, callback = null) {
 		$.get(url, function(data) {
 			// discard results if the file has already changed by the time the
 			// result arrives
@@ -699,7 +699,7 @@ OCA.Music.EmbeddedPlayer = function(onClose, onNext, onPrev, onMenuOpen, onShowL
 	 * PUBLIC INTEFACE
 	 */
 
-	this.show = function(playlistName /*optional*/) {
+	this.show = function(playlistName = null) {
 		if (!musicControls) {
 			createUi();
 		}
@@ -717,7 +717,7 @@ OCA.Music.EmbeddedPlayer = function(onClose, onNext, onPrev, onMenuOpen, onShowL
 		$('footer').css('display', 'none');
 	};
 
-	this.playFile = function(url, mime, fileId, fileName, /*optional*/ shareToken) {
+	this.playFile = function(url, mime, fileId, fileName, shareToken = null) {
 		currentFileId = fileId;
 		let fallbackTitle = OCA.Music.Utils.titleFromFilename(fileName);
 		// Set placeholders for track info fields, proper data is filled once received
@@ -738,7 +738,7 @@ OCA.Music.EmbeddedPlayer = function(onClose, onNext, onPrev, onMenuOpen, onShowL
 		});
 	};
 
-	this.playExtUrl = function(url, caption, /*optional*/ shareToken) {
+	this.playExtUrl = function(url, caption, shareToken = null) {
 		currentFileId = null;
 		updateMetadata({
 			title: caption,
diff --git a/js/embedded/main.js b/js/embedded/main.js
index 852d573b3..b4e8f97ed 100644
--- a/js/embedded/main.js
+++ b/js/embedded/main.js
@@ -275,7 +275,7 @@ function initEmbeddedPlayer() {
 		jumpToPlaylistFile(mPlaylist.currentFile());
 	}
 
-	function openPlaylistFile(onReadyCallback /*optional*/) {
+	function openPlaylistFile(onReadyCallback = null) {
 		mPlayingListFile = true;
 		let $file = mFileList.findFileEl(mCurrentFile.name);
 
diff --git a/js/embedded/playlistfileservice.js b/js/embedded/playlistfileservice.js
index 15bbeaa6e..31bbac024 100644
--- a/js/embedded/playlistfileservice.js
+++ b/js/embedded/playlistfileservice.js
@@ -16,7 +16,7 @@ OCA.Music.PlaylistFileService = class {
 	static #fileId = null;
 	static #data = null;
 
-	static readFile(fileId, onSuccess, onFail, shareToken /*optional*/) {
+	static readFile(fileId, onSuccess, onFail, shareToken = null) {
 
 		if (fileId == this.#fileId && this.#data !== null) {
 			onSuccess(this.#data);
diff --git a/js/shared/gaplessplayer.js b/js/shared/gaplessplayer.js
index 56782781f..84a0412b7 100644
--- a/js/shared/gaplessplayer.js
+++ b/js/shared/gaplessplayer.js
@@ -57,12 +57,12 @@ OCA.Music.GaplessPlayer = class {
 		this.#currentPlayer.seek(ratio);
 	}
 
-	seekForward(msecs /*optional*/) {
+	seekForward(msecs = 10000) {
 		this.#currentPlayer.seekForward(msecs);
 	}
 
-	seekBackward(msecs /*optional*/) {
-		this.#currentPlayer.seekForward(msecs);
+	seekBackward(msecs = 10000) {
+		this.#currentPlayer.seekBackward(msecs);
 	}
 
 	playPosition() {
diff --git a/js/shared/playerwrapper.js b/js/shared/playerwrapper.js
index 592529346..69120100b 100644
--- a/js/shared/playerwrapper.js
+++ b/js/shared/playerwrapper.js
@@ -292,9 +292,8 @@ OCA.Music.PlayerWrapper = class {
 			}
 			else if (msecs === 0 && this.#duration > 0) {
 				// seeking to the beginning can be simulated even when seeking in general is not supported
-				let url = this.#url;
 				let playing = this.#playing;
-				this.fromUrl(url);
+				this.fromUrl(this.#url);
 				this.trigger('progress', 0);
 				if (playing) {
 					this.play();
@@ -310,13 +309,11 @@ OCA.Music.PlayerWrapper = class {
 		this.seekMsecs(ratio * this.#duration);
 	}
 
-	seekForward(msecs /*optional*/) {
-		msecs = msecs || 10000;
+	seekForward(msecs = 10000) {
 		this.seekMsecs(this.#position + msecs);
 	}
 
-	seekBackward(msecs /*optional*/) {
-		msecs = msecs || 10000;
+	seekBackward(msecs = 10000) {
 		this.seekMsecs(this.#position - msecs);
 	}