diff --git a/.eslintrc.json b/.eslintrc.json
index 32330f8..baa189d 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -1,34 +1,44 @@
 {
   "env": {
-    "es6": false,
     "browser": true
   },
   "globals": {
     "scliveticker": "readonly",
     "wp": "readonly"
   },
-  "extends": [
-    "plugin:@wordpress/eslint-plugin/custom",
-    "plugin:@wordpress/eslint-plugin/es5",
-    "plugin:@wordpress/eslint-plugin/i18n"
-  ],
   "rules": {
     "@wordpress/i18n-text-domain": [
       "error",
       {
-        "allowedTextDomain": [ "stklcode-liveticker" ]
+        "allowedTextDomain": ["stklcode-liveticker"]
       }
     ]
   },
   "overrides": [
     {
-      "files": [
-        "*"
-      ],
+      "files": ["*"],
       "rules": {
         "no-var": "off",
         "object-shorthand": "off"
       }
+    },
+    {
+      "files": ["scripts/block.js"],
+      "env": {
+        "es6": true
+      },
+      "extends": ["plugin:@wordpress/eslint-plugin/recommended"]
+    },
+    {
+      "files": ["scripts/liveticker.js"],
+      "env": {
+        "es6": false
+      },
+      "extends": [
+        "plugin:@wordpress/eslint-plugin/custom",
+        "plugin:@wordpress/eslint-plugin/es5",
+        "plugin:@wordpress/eslint-plugin/i18n"
+      ]
     }
   ]
 }
diff --git a/scripts/block.js b/scripts/block.js
index d778544..e37ad52 100644
--- a/scripts/block.js
+++ b/scripts/block.js
@@ -3,76 +3,59 @@
  *
  * Gutenberg Block to integrate the liveticker widget without shortcode.
  */
-( function() {
-	var __ = wp.i18n.__;
-	var registerBlockType = wp.blocks.registerBlockType;
-	var registerStore = wp.data.registerStore;
-	var withSelect = wp.data.withSelect;
-	var el = wp.element.createElement;
+{
+	const __ = wp.i18n.__;
+	const registerBlockType = wp.blocks.registerBlockType;
+	const registerStore = wp.data.registerStore;
+	const withSelect = wp.data.withSelect;
+	const el = wp.element.createElement;
 
 	/**
 	 * Datastore actions.
 	 */
-	var actions = {
-		setTickers: function( tickers ) {
-			return {
-				type: 'SET_TICKERS',
-				tickers: tickers,
-			};
-		},
-		getTickers: function( path ) {
-			return {
-				type: 'RECEIVE_TICKERS',
-				path: path,
-			};
-		},
+	const actions = {
+		setTickers: (tickers) => ({ type: 'SET_TICKERS', tickers }),
 	};
 
-	registerStore( 'scliveticker/ticker', {
-		reducer: function( state, action ) {
-			if ( undefined === state ) {
-				state = { tickers: null };
-			}
-			switch ( action.type ) {
+	registerStore('scliveticker/ticker', {
+		reducer: (state = { tickers: null }, action) => {
+			switch (action.type) {
 				case 'SET_TICKERS':
-					state.tickers = action.tickers;
+					return {
+						...state,
+						tickers: action.tickers,
+					};
+				default:
 					return state;
-				case 'RECEIVE_TICKERS':
-					return action.tickers;
 			}
-
-			return state;
 		},
 
-		actions: actions,
+		actions,
 
 		selectors: {
-			receiveTickers: function( state ) {
-				return state.tickers;
-			},
+			receiveTickers: (state) => state.tickers,
 		},
 
 		resolvers: {
-			receiveTickers: function() {
-				return wp.apiFetch( { path: '/wp/v2/scliveticker_ticker' } ).then( function( tickers ) {
-					return actions.setTickers( tickers.map( function( t ) {
-						return {
-							name: t.name,
-							slug: t.slug,
-						};
-					} ) );
-				} );
-			},
+			receiveTickers: () =>
+				wp
+					.apiFetch({ path: '/wp/v2/scliveticker_ticker' })
+					.then((tickers) =>
+						actions.setTickers(
+							tickers.map((t) => ({
+								name: t.name,
+								slug: t.slug,
+							}))
+						)
+					),
 		},
-	} );
+	});
 
-	registerBlockType( 'scliveticker/ticker', {
-		title: __( 'Liveticker', 'stklcode-liveticker' ),
+	registerBlockType('scliveticker/ticker', {
+		title: __('Liveticker', 'stklcode-liveticker'),
 		icon: 'rss',
 		category: 'widgets',
-		keywords: [
-			__( 'Liveticker', 'stklcode-liveticker' ),
-		],
+		keywords: [__('Liveticker', 'stklcode-liveticker')],
 		attributes: {
 			ticker: {
 				type: 'string',
@@ -91,20 +74,17 @@
 				// implicit default: 'desc', left empty here for backwards compatibility of the block
 			},
 		},
-		edit: withSelect( function( select ) {
-			return {
-				tickers: select( 'scliveticker/ticker' ).receiveTickers(),
-			};
-		} )( function( props ) {
-			var label = [
-				el(
-					wp.components.Dashicon,
-					{ icon: 'rss' }
-				),
-				__( 'Liveticker', 'stklcode-liveticker' ),
+		edit: withSelect((select) => ({
+			tickers: select('scliveticker/ticker').receiveTickers(),
+		}))((props) => {
+			const { attributes, className, setAttributes, tickers } = props;
+
+			const label = [
+				el(wp.components.Dashicon, { icon: 'rss' }),
+				__('Liveticker', 'stklcode-liveticker'),
 			];
-			var content;
-			if ( null === props.tickers ) {
+			let content;
+			if (null === tickers) {
 				// Tickers not yet loaded.
 				content = [
 					el(
@@ -112,9 +92,9 @@
 						{ className: 'components-base-control label' },
 						label
 					),
-					el( wp.components.Spinner ),
+					el(wp.components.Spinner),
 				];
-			} else if ( 0 === props.tickers.length ) {
+			} else if (0 === tickers.length) {
 				// No tickers available.
 				content = [
 					el(
@@ -122,94 +102,88 @@
 						{ className: 'components-base-control label' },
 						label
 					),
-					el( 'span', null, __( 'No tickers available', 'stklcode-liveticker' ) ),
+					el(
+						'span',
+						null,
+						__('No tickers available', 'stklcode-liveticker')
+					),
 				];
 			} else {
 				// Tickers loaded and available.
-				if ( 0 === props.attributes.ticker.length && props.tickers.length > 0 ) {
-					props.attributes.ticker = props.tickers[ 0 ].slug;
+				if (!attributes.ticker && tickers.length > 0) {
+					setAttributes({ ticker: tickers[0].slug });
 				}
 				content = [
-					el(
-						wp.components.SelectControl,
-						{
-							label: label,
-							value: props.attributes.ticker,
-							options: props.tickers.map( function( t ) {
-								return {
-									value: t.slug,
-									label: t.name,
-								};
-							} ),
-							onChange: function( val ) {
-								props.setAttributes( { ticker: val } );
-							},
-						}
-					),
-					el(
-						wp.components.TextControl,
-						{
-							label: __( 'Number of Ticks', 'stklcode-liveticker' ),
-							type: 'number',
-							min: 1,
-							step: 1,
-							disabled: props.attributes.unlimited,
-							value: props.attributes.limit,
-							onChange: function( val ) {
-								props.setAttributes( { limit: Number( val ) } );
+					el(wp.components.SelectControl, {
+						label,
+						value: attributes.ticker,
+						options: tickers.map((t) => ({
+							value: t.slug,
+							label: t.name,
+						})),
+						onChange: (val) => {
+							setAttributes({ ticker: val });
+						},
+					}),
+					el(wp.components.TextControl, {
+						label: __('Number of Ticks', 'stklcode-liveticker'),
+						type: 'number',
+						min: 1,
+						step: 1,
+						disabled: attributes.unlimited,
+						value: attributes.limit,
+						onChange: (val) => {
+							setAttributes({ limit: Number(val) });
+						},
+					}),
+					el(wp.components.CheckboxControl, {
+						label: __('unlimited', 'stklcode-liveticker'),
+						checked: attributes.unlimited,
+						onChange: (val) => {
+							setAttributes({ unlimited: val });
+						},
+					}),
+					el(wp.components.SelectControl, {
+						label: __('Output direction', 'stklcode-liveticker'),
+						value: attributes.sort,
+						options: [
+							{
+								value: 'desc',
+								label: __(
+									'newest first',
+									'stklcode-liveticker'
+								),
 							},
-						}
-					),
-					el(
-						wp.components.CheckboxControl,
-						{
-							label: __( 'unlimited', 'stklcode-liveticker' ),
-							checked: props.attributes.unlimited,
-							onChange: function( val ) {
-								props.setAttributes( { unlimited: val } );
-							},
-						}
-					),
-					el(
-						wp.components.SelectControl,
-						{
-							label: __( 'Output direction', 'stklcode-liveticker' ),
-							value: props.attributes.sort,
-							options: [
-								{
-									value: 'desc',
-									label: __( 'newest first', 'stklcode-liveticker' ),
-								},
-								{
-									value: 'asc',
-									label: __( 'oldest first', 'stklcode-liveticker' ),
-								},
-							],
-							onChange: function( val ) {
-								props.setAttributes( { sort: val } );
+							{
+								value: 'asc',
+								label: __(
+									'oldest first',
+									'stklcode-liveticker'
+								),
 							},
-						}
-					),
+						],
+						onChange: (val) => {
+							setAttributes({ sort: val });
+						},
+					}),
 				];
 			}
 
 			return el(
 				'div',
-				{ className: props.className + ' components-placeholder' },
+				{ className: className + ' components-placeholder' },
 				content
 			);
-		} ),
-		save: function( props ) {
-			return el(
-				'div',
-				{
-					className: 'sclt-ajax',
-					'data-sclt-ticker': props.attributes.ticker,
-					'data-sclt-limit': props.attributes.unlimited ? 0 : props.attributes.limit,
-					'data-sclt-last': 0,
-					'data-sclt-sort': props.attributes.sort,
-				}
-			);
-		},
-	} );
-}() );
+		}),
+		save: (props) =>
+			el('div', {
+				className: 'sclt-ajax',
+				'data-sclt-ticker': props.attributes.ticker,
+				'data-sclt-limit': props.attributes.unlimited
+					? 0
+					: props.attributes.limit,
+				'data-sclt-last': 0,
+				'data-sclt-sort': props.attributes.sort,
+			}),
+	});
+}
diff --git a/scripts/liveticker.js b/scripts/liveticker.js
index 87cd68e..809dfb1 100644
--- a/scripts/liveticker.js
+++ b/scripts/liveticker.js
@@ -27,7 +27,7 @@
 		pollInterval = scliveticker.poll_interval;
 
 		// Get ticker elements.
-		ticker = [].map.call(
+		ticker = Array.prototype.map.call(
 			document.querySelectorAll( 'div.wp-block-scliveticker-ticker.sclt-ajax' ),
 			function( elem ) {
 				var o = parseElement( elem, false, ++c );
@@ -40,7 +40,7 @@
 
 		// Get widget elements.
 		ticker.concat(
-			[].map.call(
+			Array.prototype.map.call(
 				document.querySelectorAll( 'div.wp-widget-scliveticker-ticker.sclt-ajax' ),
 				function( elem ) {
 					var o = parseElement( elem, true, ++c );
@@ -81,7 +81,7 @@
 			list = document.createElement( 'ul' );
 			elem.appendChild( list );
 		} else {
-			[].forEach.call(
+			Array.prototype.forEach.call(
 				elem.querySelectorAll( 'li.sclt-tick' ),
 				function( li ) {
 					var id = li.getAttribute( 'data-sclt-tick-id' );
@@ -231,9 +231,9 @@
 		// Remove tail, if limit is set.
 		if ( 0 < t.limit && t.limit < t.ticks.children.length ) {
 			if ( 'asc' === t.sort ) {
-				old = [].slice.call( t.ticks.children, 0, -t.limit );
+				old = Array.prototype.slice.call( t.ticks.children, 0, -t.limit );
 			} else {
-				old = [].slice.call( t.ticks.children, t.limit );
+				old = Array.prototype.slice.call( t.ticks.children, t.limit );
 			}
 			old.forEach(
 				function( l ) {