diff --git a/clientonly/index.js b/clientonly/index.js
index b5b9fcbd17..7175d73661 100644
--- a/clientonly/index.js
+++ b/clientonly/index.js
@@ -12,17 +12,17 @@ const https = require("node:https");
  * @param {string} defaultValue value if no key is given at the command line
  * @returns {string} the value of the parameter
  */
-function getCommandLineParameter (key, defaultValue = undefined) {
+const getCommandLineParameter = (key, defaultValue = undefined) => {
 	const index = process.argv.indexOf(`--${key}`);
 	const value = index > -1 ? process.argv[index + 1] : undefined;
 	return value !== undefined ? String(value) : defaultValue;
-}
+};
 
 /**
  * Helper function to get server address/hostname from either the commandline or env
  * @returns {object} config object containing address, port, and tls properties
  */
-function getServerParameters () {
+const getServerParameters = () => {
 	const config = {};
 
 	// Prefer command line arguments over environment variables
@@ -34,14 +34,14 @@ function getServerParameters () {
 	config.tls = process.argv.includes("--use-tls");
 
 	return config;
-}
+};
 
 /**
  * Gets the config from the specified server url
  * @param {string} url location where the server is running.
  * @returns {Promise} the config
  */
-function getServerConfig (url) {
+const getServerConfig = (url) => {
 	// Return new pending promise
 	return new Promise((resolve, reject) => {
 		// Select http or https module, depending on requested url
@@ -67,21 +67,21 @@ function getServerConfig (url) {
 			reject(new Error(`Unable to read config from server (${url}) (${error.message})`));
 		});
 	});
-}
+};
 
 /**
  * Print a message to the console in case of errors
  * @param {string} message error message to print
  * @param {number} code error code for the exit call
  */
-function fail (message, code = 1) {
+const fail = (message, code = 1) => {
 	if (message !== undefined && typeof message === "string") {
 		console.error(message);
 	} else {
 		console.error("Usage: 'node clientonly --address 192.168.1.10 --port 8080 [--use-tls]'");
 	}
 	process.exit(code);
-}
+};
 
 /**
  * Starts the client by connecting to the server and launching the Electron application
@@ -89,7 +89,7 @@ function fail (message, code = 1) {
  * @param {string} prefix http or https prefix
  * @async
  */
-async function startClient (config, prefix) {
+const startClient = async (config, prefix) => {
 	try {
 		const serverUrl = `${prefix}${config.address}:${config.port}/config/`;
 		console.log(`Client: Connecting to server at ${serverUrl}`);
@@ -143,7 +143,7 @@ async function startClient (config, prefix) {
 	} catch (reason) {
 		fail(`Unable to connect to server: (${reason})`);
 	}
-}
+};
 
 // Main execution
 const config = getServerParameters();
diff --git a/defaultmodules/compliments/compliments.js b/defaultmodules/compliments/compliments.js
index 7bee06eed3..9ce033c8b6 100644
--- a/defaultmodules/compliments/compliments.js
+++ b/defaultmodules/compliments/compliments.js
@@ -112,7 +112,7 @@ Module.register("compliments", {
 			return 0;
 		}
 
-		const generate = function () {
+		const generate = () => {
 			return Math.floor(Math.random() * compliments.length);
 		};
 
diff --git a/defaultmodules/newsfeed/newsfeed.js b/defaultmodules/newsfeed/newsfeed.js
index 9a09a07406..2a8e6c89b2 100644
--- a/defaultmodules/newsfeed/newsfeed.js
+++ b/defaultmodules/newsfeed/newsfeed.js
@@ -261,7 +261,7 @@ Module.register("newsfeed", {
 		}
 
 		if (this.config.prohibitedWords.length > 0) {
-			newsItems = newsItems.filter(function (item) {
+			newsItems = newsItems.filter((item) => {
 				for (const word of this.config.prohibitedWords) {
 					if (item.title.toLowerCase().indexOf(word.toLowerCase()) > -1) {
 						return false;
diff --git a/defaultmodules/weather/provider-utils.js b/defaultmodules/weather/provider-utils.js
index 5984926468..a7e4eccb5b 100644
--- a/defaultmodules/weather/provider-utils.js
+++ b/defaultmodules/weather/provider-utils.js
@@ -9,7 +9,7 @@ const SunCalc = require("suncalc");
  * @param {string} weatherType - OpenWeatherMap icon code (e.g., "01d", "02n")
  * @returns {string|null} Internal weather type
  */
-function convertWeatherType (weatherType) {
+const convertWeatherType = (weatherType) => {
 	const weatherTypes = {
 		"01d": "day-sunny",
 		"02d": "day-cloudy",
@@ -32,7 +32,7 @@ function convertWeatherType (weatherType) {
 	};
 
 	return weatherTypes.hasOwnProperty(weatherType) ? weatherTypes[weatherType] : null;
-}
+};
 
 /**
  * Apply timezone offset to a date
@@ -40,10 +40,10 @@ function convertWeatherType (weatherType) {
  * @param {number} offsetMinutes - Timezone offset in minutes
  * @returns {Date} Date with applied offset
  */
-function applyTimezoneOffset (date, offsetMinutes) {
+const applyTimezoneOffset = (date, offsetMinutes) => {
 	const utcTime = date.getTime() + (date.getTimezoneOffset() * 60000);
 	return new Date(utcTime + (offsetMinutes * 60000));
-}
+};
 
 /**
  * Limit decimal places for coordinates (truncate, not round)
@@ -51,7 +51,7 @@ function applyTimezoneOffset (date, offsetMinutes) {
  * @param {number} decimals - Maximum number of decimal places
  * @returns {number} Value with limited decimal places
  */
-function limitDecimals (value, decimals) {
+const limitDecimals = (value, decimals) => {
 	const str = value.toString();
 	if (str.includes(".")) {
 		const parts = str.split(".");
@@ -60,7 +60,7 @@ function limitDecimals (value, decimals) {
 		}
 	}
 	return value;
-}
+};
 
 /**
  * Get sunrise and sunset times for a given date and location
@@ -69,13 +69,13 @@ function limitDecimals (value, decimals) {
  * @param {number} lon - Longitude
  * @returns {object} Object with sunrise and sunset Date objects
  */
-function getSunTimes (date, lat, lon) {
+const getSunTimes = (date, lat, lon) => {
 	const sunTimes = SunCalc.getTimes(date, lat, lon);
 	return {
 		sunrise: sunTimes.sunrise,
 		sunset: sunTimes.sunset
 	};
-}
+};
 
 /**
  * Check if a given time is during daylight hours
@@ -84,52 +84,52 @@ function getSunTimes (date, lat, lon) {
  * @param {Date} sunset - Sunset time
  * @returns {boolean} True if during daylight hours
  */
-function isDayTime (date, sunrise, sunset) {
+const isDayTime = (date, sunrise, sunset) => {
 	if (!sunrise || !sunset) {
 		return true; // Default to day if times unavailable
 	}
 	return date >= sunrise && date < sunset;
-}
+};
 
 /**
  * Format timezone offset as string (e.g., "+01:00", "-05:30")
  * @param {number} offsetMinutes - Timezone offset in minutes (use -new Date().getTimezoneOffset() for local)
  * @returns {string} Formatted offset string
  */
-function formatTimezoneOffset (offsetMinutes) {
+const formatTimezoneOffset = (offsetMinutes) => {
 	const hours = Math.floor(Math.abs(offsetMinutes) / 60);
 	const minutes = Math.abs(offsetMinutes) % 60;
 	const sign = offsetMinutes >= 0 ? "+" : "-";
 	return `${sign}${String(hours).padStart(2, "0")}:${String(minutes).padStart(2, "0")}`;
-}
+};
 
 /**
  * Get date string in YYYY-MM-DD format (local time)
  * @param {Date} date - The date to format
  * @returns {string} Date string in YYYY-MM-DD format
  */
-function getDateString (date) {
+const getDateString = (date) => {
 	const year = date.getFullYear();
 	const month = String(date.getMonth() + 1).padStart(2, "0");
 	const day = String(date.getDate()).padStart(2, "0");
 	return `${year}-${month}-${day}`;
-}
+};
 
 /**
  * Convert wind speed from km/h to m/s
  * @param {number} kmh - Wind speed in km/h
  * @returns {number} Wind speed in m/s
  */
-function convertKmhToMs (kmh) {
+const convertKmhToMs = (kmh) => {
 	return kmh / 3.6;
-}
+};
 
 /**
  * Convert cardinal wind direction string to degrees
  * @param {string} direction - Cardinal direction (e.g., "N", "NNE", "SW")
  * @returns {number|null} Direction in degrees (0-360) or null if unknown
  */
-function cardinalToDegrees (direction) {
+const cardinalToDegrees = (direction) => {
 	const directions = {
 		N: 0,
 		NNE: 22.5,
@@ -149,7 +149,7 @@ function cardinalToDegrees (direction) {
 		NNW: 337.5
 	};
 	return directions[direction] ?? null;
-}
+};
 
 /**
  * Validate and limit coordinate precision
@@ -157,7 +157,7 @@ function cardinalToDegrees (direction) {
  * @param {number} maxDecimals - Maximum decimal places to preserve
  * @throws {Error} If coordinates are missing or invalid
  */
-function validateCoordinates (config, maxDecimals = 4) {
+const validateCoordinates = (config, maxDecimals = 4) => {
 	if (config.lat == null || config.lon == null
 	  || !Number.isFinite(config.lat) || !Number.isFinite(config.lon)) {
 		throw new Error("Latitude and longitude are required");
@@ -165,7 +165,7 @@ function validateCoordinates (config, maxDecimals = 4) {
 
 	config.lat = limitDecimals(config.lat, maxDecimals);
 	config.lon = limitDecimals(config.lon, maxDecimals);
-}
+};
 
 module.exports = {
 	convertWeatherType,
diff --git a/js/alias-resolver.js b/js/alias-resolver.js
index 602e06677e..76213dc3b4 100644
--- a/js/alias-resolver.js
+++ b/js/alias-resolver.js
@@ -21,7 +21,7 @@ const resolved = Object.fromEntries(
 // Prevent multiple patching if this file is required more than once.
 if (!Module._mmAliasPatched) {
 	const origResolveFilename = Module._resolveFilename;
-	Module._resolveFilename = function (request, parent, isMain, options) {
+	Module._resolveFilename = (request, parent, isMain, options) => {
 		if (Object.prototype.hasOwnProperty.call(resolved, request)) {
 			return resolved[request];
 		}
diff --git a/js/animateCSS.js b/js/animateCSS.js
index eacb51d3a8..2df8bb4fca 100644
--- a/js/animateCSS.js
+++ b/js/animateCSS.js
@@ -128,7 +128,7 @@ const AnimateCSSOut = [
  * @param {string} [animation] animation name.
  * @param {number} [animationTime] animation duration.
  */
-function addAnimateCSS (element, animation, animationTime) {
+const addAnimateCSS = (element, animation, animationTime) => {
 	const animationName = `animate__${animation}`;
 	const node = document.getElementById(element);
 	if (!node) {
@@ -138,14 +138,14 @@ function addAnimateCSS (element, animation, animationTime) {
 	}
 	node.style.setProperty("--animate-duration", `${animationTime}s`);
 	node.classList.add("animate__animated", animationName);
-}
+};
 
 /**
  * Remove an animation with Animate CSS
  * @param {string} [element] div element to animate.
  * @param {string} [animation] animation name.
  */
-function removeAnimateCSS (element, animation) {
+const removeAnimateCSS = (element, animation) => {
 	const animationName = `animate__${animation}`;
 	const node = document.getElementById(element);
 	if (!node) {
@@ -155,5 +155,5 @@ function removeAnimateCSS (element, animation) {
 	}
 	node.classList.remove("animate__animated", animationName);
 	node.style.removeProperty("--animate-duration");
-}
+};
 if (typeof window === "undefined") module.exports = { AnimateCSSIn, AnimateCSSOut, addAnimateCSS, removeAnimateCSS };
diff --git a/js/app.js b/js/app.js
index 6fee30cc99..159201b3e9 100644
--- a/js/app.js
+++ b/js/app.js
@@ -68,7 +68,7 @@ function App () {
 	 * Loads a specific module.
 	 * @param {string} module The name of the module (including subpath).
 	 */
-	function loadModule (module) {
+	const loadModule = (module) => {
 		const elements = module.split("/");
 		const moduleName = elements[elements.length - 1];
 		let moduleFolder = path.resolve(`${global.root_path}/${env.modulesDir}`, module);
@@ -130,14 +130,14 @@ function App () {
 
 			m.loaded();
 		}
-	}
+	};
 
 	/**
 	 * Loads all modules.
 	 * @param {Module[]} modules All modules to be loaded
 	 * @returns {Promise} A promise that is resolved when all modules been loaded
 	 */
-	async function loadModules (modules) {
+	const loadModules = async (modules) => {
 		Log.log("Loading module helpers ...");
 
 		for (const module of modules) {
@@ -145,7 +145,7 @@ function App () {
 		}
 
 		Log.log("All module helpers loaded.");
-	}
+	};
 
 	/**
 	 * Compare two semantic version numbers and return the difference.
@@ -154,7 +154,7 @@ function App () {
 	 * @returns {number} A positive number if a is larger than b, a negative
 	 * number if a is smaller and 0 if they are the same
 	 */
-	function cmpVersions (a, b) {
+	const cmpVersions = (a, b) => {
 		let i, diff;
 		const regExStrip0 = /(\.0+)+$/;
 		const segmentsA = a.replace(regExStrip0, "").split(".");
@@ -168,7 +168,7 @@ function App () {
 			}
 		}
 		return segmentsA.length - segmentsB.length;
-	}
+	};
 
 	/**
 	 * Start the core app.
@@ -177,7 +177,7 @@ function App () {
 	 * @async
 	 * @returns {Promise<object>} the config used
 	 */
-	this.start = async function () {
+	this.start = async () => {
 		try {
 			const configObj = Utils.loadConfig();
 			global.config = configObj.fullConf;
@@ -277,7 +277,7 @@ function App () {
 	 * @returns {Promise} A promise that is resolved when all node_helpers and
 	 * the http server has been closed
 	 */
-	this.stop = async function () {
+	this.stop = async () => {
 		const nodePromises = [];
 		for (const nodeHelper of nodeHelpers) {
 			try {
diff --git a/js/electron.js b/js/electron.js
index 22e32d7495..bb6a61abe2 100644
--- a/js/electron.js
+++ b/js/electron.js
@@ -32,7 +32,7 @@ let mainWindow;
 /**
  * Create and show the main browser window.
  */
-function createWindow () {
+const createWindow = () => {
 
 	/*
 	 * see https://www.electronjs.org/docs/latest/api/screen
@@ -143,7 +143,7 @@ function createWindow () {
 	mainWindow.once("ready-to-show", () => {
 		mainWindow.show();
 	});
-}
+};
 
 // Quit when all windows are closed.
 app.on("window-all-closed", () => {
@@ -196,7 +196,7 @@ app.on("certificate-error", (event, webContents, url, error, certificate, callba
 /**
  * Bootstrap Electron: launch the client-only viewer and/or the full core application.
  */
-async function bootstrapElectron () {
+const bootstrapElectron = async () => {
 	if (process.env.clientonly) {
 		await app.whenReady();
 		Log.log("Launching client viewer application.");
@@ -213,6 +213,6 @@ async function bootstrapElectron () {
 		Log.log("Launching application.");
 		createWindow();
 	}
-}
+};
 
 bootstrapElectron();
diff --git a/js/electron_helper.js b/js/electron_helper.js
index 6eca6e9178..eeecd7ef9b 100644
--- a/js/electron_helper.js
+++ b/js/electron_helper.js
@@ -5,7 +5,7 @@ const Log = require("./logger");
  * @param {object} commandLine Electron commandLine API
  * @param {Array<string|object>} [electronSwitches] User-configured switches
  */
-function applyElectronSwitches (commandLine, electronSwitches) {
+const applyElectronSwitches = (commandLine, electronSwitches) => {
 	if (electronSwitches === undefined) return;
 	if (!Array.isArray(electronSwitches)) {
 		Log.error(`electronSwitches must be an array of strings or objects, got: ${JSON.stringify(electronSwitches)}`);
@@ -25,6 +25,6 @@ function applyElectronSwitches (commandLine, electronSwitches) {
 			Log.error(`Invalid electronSwitches entry: ${JSON.stringify(sw)}`);
 		}
 	}
-}
+};
 
 module.exports = { applyElectronSwitches };
diff --git a/js/ip_access_control.js b/js/ip_access_control.js
index e53b186e49..31f2d2a437 100644
--- a/js/ip_access_control.js
+++ b/js/ip_access_control.js
@@ -7,7 +7,7 @@ const Log = require("logger");
  * @param {string[]} whitelist - Array of IP addresses or CIDR ranges
  * @returns {boolean} True if IP is allowed
  */
-function isAllowed (clientIp, whitelist) {
+const isAllowed = (clientIp, whitelist) => {
 	try {
 		const addr = ipaddr.process(clientIp);
 
@@ -31,7 +31,7 @@ function isAllowed (clientIp, whitelist) {
 		Log.warn(`Failed to parse client IP: ${clientIp}`);
 		return false;
 	}
-}
+};
 
 /**
  * Resolves a client IP for both Express and Socket.IO requests.
@@ -40,7 +40,7 @@ function isAllowed (clientIp, whitelist) {
  * @param {object} req - Incoming request object (Express request or Socket.IO handshake request)
  * @returns {string} The resolved client IP address
  */
-function resolveClientIp (req) {
+const resolveClientIp = (req) => {
 	const directIp = req.socket?.remoteAddress || req.connection?.remoteAddress || req.ip;
 	const LOOPBACK_WHITELIST = ["127.0.0.1", "::ffff:127.0.0.1", "::1"];
 
@@ -52,7 +52,7 @@ function resolveClientIp (req) {
 	}
 
 	return directIp;
-}
+};
 
 /**
  * Checks whether a browser Origin matches the host serving the mirror.
@@ -60,7 +60,7 @@ function resolveClientIp (req) {
  * @param {object} req - Incoming request object
  * @returns {boolean} True if the origin is same-host or absent
  */
-function isSameOrigin (req) {
+const isSameOrigin = (req) => {
 	const origin = req.headers?.origin;
 	if (!origin) return true;
 
@@ -72,7 +72,7 @@ function isSameOrigin (req) {
 	} catch {
 		return false;
 	}
-}
+};
 
 /**
  * Determines why a request is denied, or null if it is allowed.
@@ -81,7 +81,7 @@ function isSameOrigin (req) {
  * @param {string[]} whitelist - Array of allowed IP addresses or CIDR ranges (empty = any IP)
  * @returns {string|null} A human-readable denial reason, or null when allowed
  */
-function accessDenialReason (req, whitelist) {
+const accessDenialReason = (req, whitelist) => {
 	// Strip control characters from the attacker-controlled Origin header before logging it
 	if (!isSameOrigin(req)) return `Origin ${String(req.headers?.origin).replace(/[\r\n]/g, "")} is not allowed`;
 
@@ -91,36 +91,36 @@ function accessDenialReason (req, whitelist) {
 	}
 
 	return null;
-}
+};
 
 /**
  * Creates an Express middleware enforcing same-origin and the IP whitelist.
  * @param {string[]} whitelist - Array of allowed IP addresses or CIDR ranges
  * @returns {import("express").RequestHandler} Express middleware function
  */
-function ipAccessControl (whitelist) {
-	return function (req, res, next) {
+const ipAccessControl = (whitelist) => {
+	return (req, res, next) => {
 		const reason = accessDenialReason(req, whitelist);
 		if (!reason) return next();
 
 		Log.warn(`${reason} to access the mirror`);
 		res.status(403).send("This device is not allowed to access your mirror. <br> Please check your config.js or config.js.sample to change this.");
 	};
-}
+};
 
 /**
  * Creates a Socket.IO `allowRequest` handler enforcing the same rules as the HTTP middleware.
  * @param {string[]} whitelist - Array of allowed IP addresses or CIDR ranges
  * @returns {(req: object, callback: (err: string | null, success: boolean) => void) => void} Socket.IO allowRequest handler
  */
-function socketIpAccessControl (whitelist) {
-	return function (req, callback) {
+const socketIpAccessControl = (whitelist) => {
+	return (req, callback) => {
 		const reason = accessDenialReason(req, whitelist);
 		if (!reason) return callback(null, true);
 
 		Log.warn(`${reason} to connect to the mirror socket`);
 		callback("This device is not allowed to access your mirror.", false);
 	};
-}
+};
 
 module.exports = { ipAccessControl, socketIpAccessControl };
diff --git a/js/loader.js b/js/loader.js
index 9becc9ced9..de667c945e 100644
--- a/js/loader.js
+++ b/js/loader.js
@@ -10,19 +10,19 @@ const moduleObjects = [];
  * Get environment variables from config.
  * @returns {object} Env vars with modulesDir and customCss paths from config.
  */
-function getEnvVarsFromConfig () {
+const getEnvVarsFromConfig = () => {
 	return {
 		modulesDir: globalThis.config.foreignModulesDir || "modules",
 		defaultModulesDir: globalThis.config.defaultModulesDir || "defaultmodules",
 		customCss: globalThis.config.customCss || "config/custom.css"
 	};
-}
+};
 
 /**
  * Retrieve object of env variables.
  * @returns {object} with key: values as assembled in js/server_functions.js
  */
-async function getEnvVars () {
+const getEnvVars = async () => {
 	// In test mode, skip server fetch and use config values directly
 	if (typeof process !== "undefined" && process.env && process.env.mmTestMode === "true") {
 		return getEnvVarsFromConfig();
@@ -37,12 +37,12 @@ async function getEnvVars () {
 		Log.error("Unable to retrieve env configuration", error);
 		return getEnvVarsFromConfig();
 	}
-}
+};
 
 /**
  * Loops through all modules and requests start for every module.
  */
-async function startModules () {
+const startModules = async () => {
 	const modulePromises = [];
 	for (const module of moduleObjects) {
 		try {
@@ -72,22 +72,22 @@ async function startModules () {
 			thisModule.hide();
 		}
 	}
-}
+};
 
 /**
  * Retrieve list of all modules.
  * @returns {object[]} module data as configured in config
  */
-function getAllModules () {
+const getAllModules = () => {
 	const AllModules = globalThis.config.modules.filter((module) => (module.module !== undefined) && (MM.getAvailableModulePositions.indexOf(module.position) > -1 || typeof (module.position) === "undefined"));
 	return AllModules;
-}
+};
 
 /**
  * Generate array with module information including module paths.
  * @returns {object[]} Module information.
  */
-async function getModuleData () {
+const getModuleData = async () => {
 	const modules = getAllModules();
 	const moduleFiles = [];
 	const envVars = await getEnvVars();
@@ -134,25 +134,25 @@ async function getModuleData () {
 	});
 
 	return moduleFiles;
-}
+};
 
 /**
  * Load modules via ajax request and create module objects.
  * @param {object} module Information about the module we want to load.
  * @returns {Promise<void>} resolved when module is loaded
  */
-async function loadModule (module) {
+const loadModule = async (module) => {
 	const url = module.path + module.file;
 
 	/**
 	 * @returns {Promise<void>}
 	 */
-	async function afterLoad () {
+	const afterLoad = async () => {
 		const moduleObject = Module.create(module.name);
 		if (moduleObject) {
 			await bootstrapModule(module, moduleObject);
 		}
-	}
+	};
 
 	if (loadedModuleFiles.indexOf(url) !== -1) {
 		await afterLoad();
@@ -161,14 +161,14 @@ async function loadModule (module) {
 		loadedModuleFiles.push(url);
 		await afterLoad();
 	}
-}
+};
 
 /**
  * Bootstrap modules by setting the module data and loading the scripts & styles.
  * @param {object} module Information about the module we want to load.
  * @param {Module} mObj Modules instance.
  */
-async function bootstrapModule (module, mObj) {
+const bootstrapModule = async (module, mObj) => {
 	Log.info(`Bootstrapping module: ${module.name}`);
 	mObj.setData(module);
 
@@ -182,14 +182,14 @@ async function bootstrapModule (module, mObj) {
 	Log.log(`Translations loaded for: ${module.name}`);
 
 	moduleObjects.push(mObj);
-}
+};
 
 /**
  * Load a script or stylesheet by adding it to the dom.
  * @param {string} fileName Path of the file we want to load.
  * @returns {Promise} resolved when the file is loaded
  */
-function loadFile (fileName) {
+const loadFile = (fileName) => {
 	const extension = fileName.slice((Math.max(0, fileName.lastIndexOf(".")) || Infinity) + 1);
 	let script, stylesheet;
 
@@ -200,10 +200,10 @@ function loadFile (fileName) {
 				script = document.createElement("script");
 				script.type = "text/javascript";
 				script.src = fileName;
-				script.onload = function () {
+				script.onload = () => {
 					resolve();
 				};
-				script.onerror = function () {
+				script.onerror = () => {
 					Log.error("Error on loading script:", fileName);
 					script.remove();
 					resolve();
@@ -216,10 +216,10 @@ function loadFile (fileName) {
 				script = document.createElement("script");
 				script.type = "module";
 				script.src = fileName;
-				script.onload = function () {
+				script.onload = () => {
 					resolve();
 				};
-				script.onerror = function () {
+				script.onerror = () => {
 					Log.error("Error on loading module script:", fileName);
 					script.remove();
 					resolve();
@@ -234,10 +234,10 @@ function loadFile (fileName) {
 				stylesheet.rel = "stylesheet";
 				stylesheet.type = "text/css";
 				stylesheet.href = fileName;
-				stylesheet.onload = function () {
+				stylesheet.onload = () => {
 					resolve();
 				};
-				stylesheet.onerror = function () {
+				stylesheet.onerror = () => {
 					Log.error("Error on loading stylesheet:", fileName);
 					stylesheet.remove();
 					resolve();
@@ -245,14 +245,14 @@ function loadFile (fileName) {
 				document.getElementsByTagName("head")[0].appendChild(stylesheet);
 			});
 	}
-}
+};
 
 /* Public Methods */
 
 /**
  * Load all modules as defined in the config.
  */
-export async function loadModules () {
+export const loadModules = async () => {
 	const moduleData = await getModuleData();
 	const envVars = await getEnvVars();
 	const customCss = envVars.customCss;
@@ -269,7 +269,7 @@ export async function loadModules () {
 
 	// Start all modules.
 	await startModules();
-}
+};
 
 /**
  * Load a file (script or stylesheet).
@@ -278,7 +278,7 @@ export async function loadModules () {
  * @param {Module} module The module that calls the loadFile function.
  * @returns {Promise} resolved when the file is loaded
  */
-export function loadFileForModule (fileName, module) {
+export const loadFileForModule = (fileName, module) => {
 	if (loadedFiles.indexOf(fileName.toLowerCase()) !== -1) {
 		Log.log(`File already loaded: ${fileName}`);
 		return Promise.resolve();
@@ -302,4 +302,4 @@ export function loadFileForModule (fileName, module) {
 	// Load it based on the module path.
 	loadedFiles.push(fileName.toLowerCase());
 	return loadFile(module.file(fileName));
-}
+};
diff --git a/js/logger.js b/js/logger.js
index 28d6db5227..4038258326 100644
--- a/js/logger.js
+++ b/js/logger.js
@@ -1,5 +1,62 @@
 // Logger for MagicMirror² — works both in Node.js (CommonJS) and the browser (global).
-(function () {
+(() => {
+
+	/**
+	 * Creates the logger object. Logging is disabled when running in test mode
+	 * (Node.js) or inside jsdom (browser).
+	 * @returns {object} The logger object with log level methods.
+	 */
+	const makeLogger = () => {
+		const enableLog = typeof module !== "undefined"
+			? process.env.mmTestMode !== "true"
+			: typeof window === "object" && window.name !== "jsdom";
+
+		let logLevel;
+
+		if (enableLog) {
+			logLevel = {
+				debug: console.debug.bind(console),
+				log: console.log.bind(console),
+				info: console.info.bind(console),
+				warn: console.warn.bind(console),
+				error: console.error.bind(console),
+				group: console.group.bind(console),
+				groupCollapsed: console.groupCollapsed.bind(console),
+				groupEnd: console.groupEnd.bind(console),
+				time: console.time.bind(console),
+				timeEnd: console.timeEnd.bind(console),
+				timeStamp: console.timeStamp.bind(console)
+			};
+
+			// Only these methods are affected by setLogLevel.
+			// Utility methods (group, time, etc.) are always active.
+			logLevel.setLogLevel = (newLevel) => {
+				for (const key of ["debug", "log", "info", "warn", "error"]) {
+					const disabled = newLevel && !newLevel.includes(key.toUpperCase());
+					logLevel[key] = disabled ? () => {} : console[key].bind(console);
+				}
+			};
+		} else {
+			logLevel = {
+				debug () {},
+				log () {},
+				info () {},
+				warn () {},
+				error () {},
+				group () {},
+				groupCollapsed () {},
+				groupEnd () {},
+				time () {},
+				timeEnd () {},
+				timeStamp () {}
+			};
+
+			logLevel.setLogLevel = () => {};
+		}
+
+		return logLevel;
+	};
+
 	if (typeof module !== "undefined") {
 		if (process.env.mmTestMode !== "true") {
 			const { styleText } = require("node:util");
@@ -55,60 +112,4 @@
 		// Browser globals
 		window.Log = makeLogger();
 	}
-
-	/**
-	 * Creates the logger object. Logging is disabled when running in test mode
-	 * (Node.js) or inside jsdom (browser).
-	 * @returns {object} The logger object with log level methods.
-	 */
-	function makeLogger () {
-		const enableLog = typeof module !== "undefined"
-			? process.env.mmTestMode !== "true"
-			: typeof window === "object" && window.name !== "jsdom";
-
-		let logLevel;
-
-		if (enableLog) {
-			logLevel = {
-				debug: console.debug.bind(console),
-				log: console.log.bind(console),
-				info: console.info.bind(console),
-				warn: console.warn.bind(console),
-				error: console.error.bind(console),
-				group: console.group.bind(console),
-				groupCollapsed: console.groupCollapsed.bind(console),
-				groupEnd: console.groupEnd.bind(console),
-				time: console.time.bind(console),
-				timeEnd: console.timeEnd.bind(console),
-				timeStamp: console.timeStamp.bind(console)
-			};
-
-			// Only these methods are affected by setLogLevel.
-			// Utility methods (group, time, etc.) are always active.
-			logLevel.setLogLevel = function (newLevel) {
-				for (const key of ["debug", "log", "info", "warn", "error"]) {
-					const disabled = newLevel && !newLevel.includes(key.toUpperCase());
-					logLevel[key] = disabled ? function () {} : console[key].bind(console);
-				}
-			};
-		} else {
-			logLevel = {
-				debug () {},
-				log () {},
-				info () {},
-				warn () {},
-				error () {},
-				group () {},
-				groupCollapsed () {},
-				groupEnd () {},
-				time () {},
-				timeEnd () {},
-				timeStamp () {}
-			};
-
-			logLevel.setLogLevel = function () {};
-		}
-
-		return logLevel;
-	}
-}());
+})();
diff --git a/js/main.js b/js/main.js
index c9e31f8c35..658f050349 100644
--- a/js/main.js
+++ b/js/main.js
@@ -11,7 +11,7 @@ let modules = [];
 /**
  * Create dom objects for all modules that are configured for a specific position.
  */
-async function createDomObjects () {
+const createDomObjects = async () => {
 	const domCreationPromises = [];
 
 	modules.forEach((module) => {
@@ -64,7 +64,7 @@ async function createDomObjects () {
 	} catch (error) {
 		Log.error(error);
 	}
-}
+};
 
 /**
  * Create and render a module DOM, then notify the module.
@@ -72,7 +72,7 @@ async function createDomObjects () {
  * @param {string|null} haveAnimateIn Optional animateIn animation name.
  * @returns {Promise<void>} Resolved when module DOM is created.
  */
-async function createModuleDom (module, haveAnimateIn) {
+const createModuleDom = async (module, haveAnimateIn) => {
 	if (haveAnimateIn) {
 		await _updateDom(module, { options: { speed: 1000, animate: { in: haveAnimateIn } } }, true);
 	} else {
@@ -80,14 +80,14 @@ async function createModuleDom (module, haveAnimateIn) {
 	}
 
 	_sendNotification("MODULE_DOM_CREATED", null, null, module);
-}
+};
 
 /**
  * Select the wrapper dom object for a specific position.
  * @param {string} position The name of the position.
  * @returns {HTMLElement | void} the wrapper element
  */
-function selectWrapper (position) {
+const selectWrapper = (position) => {
 	const classes = position.replace("_", " ");
 	const parentWrapper = document.getElementsByClassName(classes);
 	if (parentWrapper.length > 0) {
@@ -96,7 +96,7 @@ function selectWrapper (position) {
 			return wrapper[0];
 		}
 	}
-}
+};
 
 /**
  * Send a notification to all modules.
@@ -105,14 +105,14 @@ function selectWrapper (position) {
  * @param {Module} sender The module that sent the notification.
  * @param {Module} [sendTo] The (optional) module to send the notification to.
  */
-function _sendNotification (notification, payload, sender, sendTo) {
+const _sendNotification = (notification, payload, sender, sendTo) => {
 	for (const m in modules) {
 		const module = modules[m];
 		if (module !== sender && (!sendTo || module === sendTo)) {
 			module.notificationReceived(notification, payload, sender);
 		}
 	}
-}
+};
 
 /**
  * Update the dom for a specific module.
@@ -121,7 +121,7 @@ function _sendNotification (notification, payload, sender, sendTo) {
  * @param {boolean} [createAnimatedDom] for displaying only animateIn (used on first start of MagicMirror)
  * @returns {Promise<void>} Resolved when the dom is fully updated.
  */
-async function _updateDom (module, updateOptions, createAnimatedDom = false) {
+const _updateDom = async (module, updateOptions, createAnimatedDom = false) => {
 	let speed = updateOptions;
 	let animateOut = null;
 	let animateIn = null;
@@ -143,7 +143,7 @@ async function _updateDom (module, updateOptions, createAnimatedDom = false) {
 	const newHeader = module.getHeader();
 	const newContent = await module.getDom();
 	await updateDomWithContent(module, speed, newHeader, newContent, animateOut, animateIn, createAnimatedDom);
-}
+};
 
 /**
  * Update the dom with the specified content
@@ -156,7 +156,7 @@ async function _updateDom (module, updateOptions, createAnimatedDom = false) {
  * @param {boolean} [createAnimatedDom] If true, apply content and trigger only animateIn (used on first start).
  * @returns {Promise<void>} Resolved after the module DOM update is applied or hide/show transition is scheduled.
  */
-async function updateDomWithContent (module, speed, newHeader, newContent, animateOut, animateIn, createAnimatedDom = false) {
+const updateDomWithContent = async (module, speed, newHeader, newContent, animateOut, animateIn, createAnimatedDom = false) => {
 	if (module.hidden || !speed) {
 		updateModuleContent(module, newHeader, newContent);
 		return;
@@ -180,7 +180,7 @@ async function updateDomWithContent (module, speed, newHeader, newContent, anima
 	if (!module.hidden) {
 		await new Promise((resolve) => _showModule(module, speed / 2, resolve, { animate: animateIn }));
 	}
-}
+};
 
 /**
  * Check if the content has changed.
@@ -189,7 +189,7 @@ async function updateDomWithContent (module, speed, newHeader, newContent, anima
  * @param {HTMLElement} newContent The new content that is generated.
  * @returns {boolean} True if the module need an update, false otherwise
  */
-function moduleNeedsUpdate (module, newHeader, newContent) {
+const moduleNeedsUpdate = (module, newHeader, newContent) => {
 	const moduleWrapper = document.getElementById(module.identifier);
 	if (moduleWrapper === null) {
 		return false;
@@ -209,7 +209,7 @@ function moduleNeedsUpdate (module, newHeader, newContent) {
 	const contentNeedsUpdate = tempContentWrapper.innerHTML !== contentWrapper[0].innerHTML;
 
 	return headerNeedsUpdate || contentNeedsUpdate;
-}
+};
 
 /**
  * Update the content of a module on screen.
@@ -217,7 +217,7 @@ function moduleNeedsUpdate (module, newHeader, newContent) {
  * @param {string} newHeader The new header that is generated.
  * @param {HTMLElement} newContent The new content that is generated.
  */
-function updateModuleContent (module, newHeader, newContent) {
+const updateModuleContent = (module, newHeader, newContent) => {
 	const moduleWrapper = document.getElementById(module.identifier);
 	if (moduleWrapper === null) {
 		return;
@@ -234,7 +234,7 @@ function updateModuleContent (module, newHeader, newContent) {
 	} else {
 		headerWrapper[0].style.display = "none";
 	}
-}
+};
 
 /**
  * Hide the module.
@@ -243,7 +243,7 @@ function updateModuleContent (module, newHeader, newContent) {
  * @param {() => void} callback Called when the animation is done.
  * @param {object} [options] Optional settings for the hide method.
  */
-function _hideModule (module, speed, callback, options = {}) {
+const _hideModule = (module, speed, callback, options = {}) => {
 	// set lockString if set in options.
 	if (options.lockString) {
 		if (module.lockStrings.indexOf(options.lockString) === -1) {
@@ -318,7 +318,7 @@ function _hideModule (module, speed, callback, options = {}) {
 			callback();
 		}
 	}
-}
+};
 
 /**
  * Show the module.
@@ -327,7 +327,7 @@ function _hideModule (module, speed, callback, options = {}) {
  * @param {() => void} callback Called when the animation is done.
  * @param {object} [options] Optional settings for the show method.
  */
-function _showModule (module, speed, callback, options = {}) {
+const _showModule = (module, speed, callback, options = {}) => {
 	// remove lockString if set in options.
 	if (options.lockString) {
 		const index = module.lockStrings.indexOf(options.lockString);
@@ -416,7 +416,7 @@ function _showModule (module, speed, callback, options = {}) {
 			callback();
 		}
 	}
-}
+};
 
 /**
  * Checks for all positions if it has visible content.
@@ -429,7 +429,7 @@ function _showModule (module, speed, callback, options = {}) {
  * an ugly top margin. By using this function, the top bar will be hidden if the
  * update notification is not visible.
  */
-function updateWrapperStates () {
+const updateWrapperStates = () => {
 	modulePositions.forEach((position) => {
 		const wrapper = selectWrapper(position);
 		const moduleWrappers = wrapper.getElementsByClassName("module");
@@ -444,13 +444,13 @@ function updateWrapperStates () {
 		// move container definitions to main CSS
 		wrapper.className = showWrapper ? "container" : "container hidden";
 	});
-}
+};
 
 /**
  * Loads the core config from the server (already combined with the system defaults).
  * @returns {Promise<object>} The loaded config.
  */
-async function loadConfig () {
+const loadConfig = async () => {
 	const basePath = globalThis.config?.basePath ?? "/";
 	const res = await fetch(new URL("config/", `${location.origin}${basePath}`));
 	if (!res.ok) {
@@ -472,31 +472,31 @@ async function loadConfig () {
 	});
 	globalThis.config = config;
 	return config;
-}
+};
 
 /**
  * Adds special selectors on a collection of modules.
  * @param {Module[]} modules Array of modules.
  */
-function setSelectionMethodsForModules (modules) {
+const setSelectionMethodsForModules = (modules) => {
 
 	/**
 	 * Filter modules with the specified classes.
 	 * @param {string|string[]} className one or multiple classnames (array or space divided).
 	 * @returns {Module[]} Filtered collection of modules.
 	 */
-	function withClass (className) {
+	const withClass = (className) => {
 		return modulesByClass(className, true);
-	}
+	};
 
 	/**
 	 * Filter modules without the specified classes.
 	 * @param {string|string[]} className one or multiple classnames (array or space divided).
 	 * @returns {Module[]} Filtered collection of modules.
 	 */
-	function exceptWithClass (className) {
+	const exceptWithClass = (className) => {
 		return modulesByClass(className, false);
-	}
+	};
 
 	/**
 	 * Filters a collection of modules based on classname(s).
@@ -504,7 +504,7 @@ function setSelectionMethodsForModules (modules) {
 	 * @param {boolean} include if the filter should include or exclude the modules with the specific classes.
 	 * @returns {Module[]} Filtered collection of modules.
 	 */
-	function modulesByClass (className, include) {
+	const modulesByClass = (className, include) => {
 		let searchClasses = className;
 		if (typeof className === "string") {
 			searchClasses = className.split(" ");
@@ -524,31 +524,31 @@ function setSelectionMethodsForModules (modules) {
 
 		setSelectionMethodsForModules(newModules);
 		return newModules;
-	}
+	};
 
 	/**
 	 * Removes a module instance from the collection.
 	 * @param {object} module The module instance to remove from the collection.
 	 * @returns {Module[]} Filtered collection of modules.
 	 */
-	function exceptModule (module) {
+	const exceptModule = (module) => {
 		const newModules = modules.filter((mod) => {
 			return mod.identifier !== module.identifier;
 		});
 
 		setSelectionMethodsForModules(newModules);
 		return newModules;
-	}
+	};
 
 	/**
 	 * Walks thru a collection of modules and executes the callback with the module as an argument.
 	 * @param {module} callback The function to execute with the module as an argument.
 	 */
-	function enumerate (callback) {
+	const enumerate = (callback) => {
 		modules.map((module) => {
 			callback(module);
 		});
-	}
+	};
 
 	if (typeof modules.withClass === "undefined") {
 		Object.defineProperty(modules, "withClass", { value: withClass, enumerable: false });
@@ -562,7 +562,7 @@ function setSelectionMethodsForModules (modules) {
 	if (typeof modules.enumerate === "undefined") {
 		Object.defineProperty(modules, "enumerate", { value: enumerate, enumerable: false });
 	}
-}
+};
 
 export const MM = {
 
diff --git a/js/module.js b/js/module.js
index 11bae13945..f45a458969 100644
--- a/js/module.js
+++ b/js/module.js
@@ -368,13 +368,13 @@ export class Module {
 	 * @param {object} [options] Optional settings for the hide method.
 	 */
 	hide (speed, callback, options = {}) {
-		let usedCallback = callback || function () {};
+		let usedCallback = callback || (() => {});
 		let usedOptions = options;
 
 		if (typeof callback === "object") {
 			Log.error("Parameter mismatch in module.hide: callback is not an optional parameter!");
 			usedOptions = callback;
-			usedCallback = function () {};
+			usedCallback = () => {};
 		}
 
 		MM.hideModule(
@@ -395,13 +395,13 @@ export class Module {
 	 * @param {object} [options] Optional settings for the show method.
 	 */
 	show (speed, callback, options) {
-		let usedCallback = callback || function () {};
+		let usedCallback = callback || (() => {});
 		let usedOptions = options;
 
 		if (typeof callback === "object") {
 			Log.error("Parameter mismatch in module.show: callback is not an optional parameter!");
 			usedOptions = callback;
-			usedCallback = function () {};
+			usedCallback = () => {};
 		}
 
 		MM.showModule(
@@ -428,7 +428,7 @@ globalThis.Module = Module;
  * @param {...object} sources Objects whose properties are merged into target.
  * @returns {object} The merged target object.
  */
-function configMerge (target, ...sources) {
+const configMerge = (target, ...sources) => {
 	const isPlainObject = (value) => value?.constructor === Object;
 
 	for (const source of sources) {
@@ -444,7 +444,7 @@ function configMerge (target, ...sources) {
 	}
 
 	return target;
-}
+};
 
 Module.definitions = {};
 
@@ -495,7 +495,7 @@ Module.register = function (name, moduleDefinition) {
  * @returns {number} A positive number if a is larger than b, a negative
  * number if a is smaller and 0 if they are the same
  */
-export function cmpVersions (a, b) {
+export const cmpVersions = (a, b) => {
 	const regExStrip0 = /(\.0+)+$/;
 	const segmentsA = a.replace(regExStrip0, "").split(".");
 	const segmentsB = b.replace(regExStrip0, "").split(".");
@@ -508,14 +508,14 @@ export function cmpVersions (a, b) {
 		}
 	}
 	return segmentsA.length - segmentsB.length;
-}
+};
 
 /**
  * Define the clone method for later use. Helper Method.
  * @param {object} obj Object to be cloned
  * @returns {object} the cloned object
  */
-export function cloneObject (obj) {
+export const cloneObject = (obj) => {
 	if (obj === null || typeof obj !== "object") {
 		return obj;
 	}
@@ -548,4 +548,4 @@ export function cloneObject (obj) {
 	}
 
 	return temp;
-}
+};
diff --git a/js/node_helper.js b/js/node_helper.js
index 6ff435bf07..a19d3d68a5 100644
--- a/js/node_helper.js
+++ b/js/node_helper.js
@@ -9,7 +9,7 @@ const { replaceSecretPlaceholder } = require("#server_functions");
  * @param {string} moduleName - Name of the module.
  * @returns {Set<string>} The secret names the module may restore.
  */
-function getAllowedSecrets (moduleName) {
+const getAllowedSecrets = (moduleName) => {
 	const modules = global.configRedacted?.modules || [];
 	const moduleConfig = modules.find((m) => m.module === moduleName);
 	const allowed = new Set();
@@ -20,7 +20,7 @@ function getAllowedSecrets (moduleName) {
 		}
 	}
 	return allowed;
-}
+};
 
 class NodeHelper {
 	init () {
diff --git a/js/server.js b/js/server.js
index 7b3c428cc2..249df5f8d7 100644
--- a/js/server.js
+++ b/js/server.js
@@ -29,7 +29,7 @@ function Server (configObj) {
 	 * Opens the server for incoming connections
 	 * @returns {Promise} A promise that is resolved when the server listens to connections
 	 */
-	this.open = function () {
+	this.open = () => {
 		return new Promise((resolve) => {
 			if (config.useHttps) {
 				const options = {
@@ -162,7 +162,7 @@ function Server (configObj) {
 	 * Closes the server and destroys all lingering connections to it.
 	 * @returns {Promise} A promise that resolves when server has successfully shut down
 	 */
-	this.close = function () {
+	this.close = () => {
 		return new Promise((resolve) => {
 			for (const socket of serverSockets.values()) {
 				socket.destroy();
diff --git a/js/server_functions.js b/js/server_functions.js
index 1d04a2f384..cf7b0627b1 100644
--- a/js/server_functions.js
+++ b/js/server_functions.js
@@ -12,9 +12,9 @@ const startUp = new Date();
  * @param {Request} req - the request
  * @param {Response} res - the result
  */
-function getStartup (req, res) {
+const getStartup = (req, res) => {
 	res.send(startUp);
-}
+};
 
 /**
  * Replace `**SECRET_ABC**` placeholders with the value of `process.env.SECRET_ABC`.
@@ -26,7 +26,7 @@ function getStartup (req, res) {
  * @param {Set<string>} [allowedSecrets] - Secret names that may be restored.
  * @returns {string} The input with the allowed placeholders replaced.
  */
-function replaceSecretPlaceholder (input, allowedSecrets) {
+const replaceSecretPlaceholder = (input, allowedSecrets) => {
 	if (global.config.cors === "allowAll") {
 		if (input.includes("**SECRET_")) {
 			Log.error("Replacing secrets doesn't work with CORS `allowAll`, you need to set `cors` to `disabled` or `allowWhitelist` in `config.js`");
@@ -42,7 +42,7 @@ function replaceSecretPlaceholder (input, allowedSecrets) {
 		// Load the real value from the environment. Fallback to placeholder if missing.
 		return process.env[secretName] || placeholder;
 	});
-}
+};
 
 /**
  * A method that forwards HTTP Get-methods to the internet to avoid CORS-errors.
@@ -54,7 +54,7 @@ function replaceSecretPlaceholder (input, allowedSecrets) {
  * @param {Response} res - the result
  * @returns {Promise<void>} A promise that resolves when the response is sent
  */
-async function cors (req, res) {
+const cors = async (req, res) => {
 	if (global.config.cors === "disabled") {
 		Log.error("CORS is disabled, you need to enable it in `config.js` by setting `cors` to `allowAll` or `allowWhitelist`");
 		return res.status(403).json({ error: "CORS proxy is disabled" });
@@ -142,14 +142,14 @@ async function cors (req, res) {
 		}
 		res.status(500).json({ error: error.message });
 	}
-}
+};
 
 /**
  * Gets headers and values to attach to the web request.
  * @param {string} url - The url containing the headers and values to send.
  * @returns {object} An object specifying name and value of the headers.
  */
-function getHeadersToSend (url) {
+const getHeadersToSend = (url) => {
 	const headersToSend = { "User-Agent": getUserAgent() };
 	const headersToSendMatch = new RegExp("sendheaders=(.+?)(&|$)", "g").exec(url);
 	if (headersToSendMatch) {
@@ -163,14 +163,14 @@ function getHeadersToSend (url) {
 		}
 	}
 	return headersToSend;
-}
+};
 
 /**
  * Gets the headers expected from the response.
  * @param {string} url - The url containing the expected headers from the response.
  * @returns {string[]} headers - The name of the expected headers.
  */
-function geExpectedReceivedHeaders (url) {
+const geExpectedReceivedHeaders = (url) => {
 	const expectedReceivedHeaders = ["Content-Type"];
 	const expectedReceivedHeadersMatch = new RegExp("expectedheaders=(.+?)(&|$)", "g").exec(url);
 	if (expectedReceivedHeadersMatch) {
@@ -180,35 +180,35 @@ function geExpectedReceivedHeaders (url) {
 		}
 	}
 	return expectedReceivedHeaders;
-}
+};
 
 /**
  * Gets the HTML to display the magic mirror.
  * @param {Request} req - the request
  * @param {Response} res - the result
  */
-function getHtml (req, res) {
+const getHtml = (req, res) => {
 	let html = fs.readFileSync(path.resolve(`${global.root_path}/index.html`), { encoding: "utf8" });
 	html = html.replace("#VERSION#", global.version);
 	html = html.replace("#TESTMODE#", global.mmTestMode);
 
 	res.send(html);
-}
+};
 
 /**
  * Gets the MagicMirror version.
  * @param {Request} req - the request
  * @param {Response} res - the result
  */
-function getVersion (req, res) {
+const getVersion = (req, res) => {
 	res.send(global.version);
-}
+};
 
 /**
  * Gets the preferred `User-Agent`
  * @returns {string} `User-Agent` to be used
  */
-function getUserAgent () {
+const getUserAgent = () => {
 	const defaultUserAgent = `Mozilla/5.0 (Node.js ${Number(process.version.match(/^v(\d+\.\d+)/)[1])}) MagicMirror/${global.version}`;
 
 	if (typeof global.config === "undefined") {
@@ -223,13 +223,13 @@ function getUserAgent () {
 		default:
 			return defaultUserAgent;
 	}
-}
+};
 
 /**
  * Gets environment variables needed in the browser.
  * @returns {object} environment variables key: values
  */
-function getEnvVarsAsObj () {
+const getEnvVarsAsObj = () => {
 	const obj = { modulesDir: `${global.config.foreignModulesDir}`, defaultModulesDir: `${global.config.defaultModulesDir}`, customCss: `${global.config.customCss}` };
 	if (process.env.MM_MODULES_DIR) {
 		obj.modulesDir = process.env.MM_MODULES_DIR.replace(`${global.root_path}/`, "");
@@ -239,17 +239,17 @@ function getEnvVarsAsObj () {
 	}
 
 	return obj;
-}
+};
 
 /**
  * Gets environment variables needed in the browser.
  * @param {Request} req - the request
  * @param {Response} res - the result
  */
-function getEnvVars (req, res) {
+const getEnvVars = (req, res) => {
 	const obj = getEnvVarsAsObj();
 	res.send(obj);
-}
+};
 
 /**
  * Resolves the HTTP server port. The `MM_PORT` environment variable takes
@@ -257,15 +257,15 @@ function getEnvVars (req, res) {
  * @param {object} [config] the configuration to read the port from (defaults to global.config)
  * @returns {number} the port the server should listen on
  */
-function getServerPort (config = global.config) {
+const getServerPort = (config = global.config) => {
 	return Number(process.env.MM_PORT || config?.port || 8080);
-}
+};
 
 /**
  * Get the config file path from environment or default location
  * @returns {string} The absolute config file path
  */
-function getConfigFilePath () {
+const getConfigFilePath = () => {
 	// Ensure root_path is set (for standalone contexts like watcher)
 	if (!global.root_path) {
 		global.root_path = path.resolve(`${__dirname}/../`);
@@ -277,6 +277,6 @@ function getConfigFilePath () {
 	}
 
 	return path.resolve(global.configuration_file || `${global.root_path}/config/config.js`);
-}
+};
 
 module.exports = { cors, getHtml, getVersion, getStartup, getEnvVars, getEnvVarsAsObj, getUserAgent, getServerPort, getConfigFilePath, replaceSecretPlaceholder };
diff --git a/js/socketclient.js b/js/socketclient.js
index 8e52b694c0..9691247d61 100644
--- a/js/socketclient.js
+++ b/js/socketclient.js
@@ -23,7 +23,7 @@ export const MMSocket = function (moduleName) {
 		pingTimeout: 120000 // wait up to 2 mins for a pong
 	});
 
-	let notificationCallback = function () {};
+	let notificationCallback = () => {};
 
 	const onevent = this.socket.onevent;
 	this.socket.onevent = (packet) => {
diff --git a/js/translator.js b/js/translator.js
index cf0b3827af..94c90e1f75 100644
--- a/js/translator.js
+++ b/js/translator.js
@@ -1,13 +1,13 @@
 /* global translations */
 
-export const Translator = (function () {
+export const Translator = (() => {
 
 	/**
 	 * Load a JSON file via fetch.
 	 * @param {string} file Path of the file we want to load.
 	 * @returns {Promise<object>} the translations in the specified file
 	 */
-	async function loadJSON (file) {
+	const loadJSON = async (file) => {
 		const baseHref = document.baseURI;
 		const url = new URL(file, baseHref);
 
@@ -21,7 +21,7 @@ export const Translator = (function () {
 			Log.error(`Loading json file =${file} failed`);
 			return null;
 		}
-	}
+	};
 
 	return {
 		coreTranslations: {},
@@ -47,7 +47,7 @@ export const Translator = (function () {
 			 * @param {object} variables Variables for the placeholder
 			 * @returns {string} the template filled with the variables
 			 */
-			function createStringFromTemplate (template, variables) {
+			const createStringFromTemplate = (template, variables) => {
 				if (Object.prototype.toString.call(template) !== "[object String]") {
 					return template;
 				}
@@ -58,7 +58,7 @@ export const Translator = (function () {
 				return templateToUse.replace(new RegExp("{([^}]+)}", "g"), (_unused, varName) => {
 					return varName in variables ? variables[varName] : `{${varName}}`;
 				});
-			}
+			};
 
 			if (this.translations[module.name] && key in this.translations[module.name]) {
 				return createStringFromTemplate(this.translations[module.name][key], variables);
@@ -124,4 +124,4 @@ export const Translator = (function () {
 			}
 		}
 	};
-}());
+})();
diff --git a/serveronly/watcher.js b/serveronly/watcher.js
index b65d6f9917..9cc6119da1 100644
--- a/serveronly/watcher.js
+++ b/serveronly/watcher.js
@@ -24,7 +24,7 @@ const rootDir = path.join(__dirname, "..");
  * Get the server configuration (port and address)
  * @returns {{port: number, address: string}} The server config
  */
-function getServerConfig () {
+const getServerConfig = () => {
 	if (serverConfig) return serverConfig;
 
 	try {
@@ -40,14 +40,14 @@ function getServerConfig () {
 	}
 
 	return serverConfig;
-}
+};
 
 /**
  * Check if a port is available on the configured address
  * @param {number} port The port to check
  * @returns {Promise<boolean>} True if port is available
  */
-function isPortAvailable (port) {
+const isPortAvailable = (port) => {
 	return new Promise((resolve) => {
 		const server = net.createServer();
 
@@ -64,7 +64,7 @@ function isPortAvailable (port) {
 		const { address } = getServerConfig();
 		server.listen(port, address);
 	});
-}
+};
 
 /**
  * Wait until port is available
@@ -72,7 +72,7 @@ function isPortAvailable (port) {
  * @param {number} maxAttempts Maximum number of attempts
  * @returns {Promise<void>}
  */
-async function waitForPort (port, maxAttempts = PORT_CHECK_MAX_ATTEMPTS) {
+const waitForPort = async (port, maxAttempts = PORT_CHECK_MAX_ATTEMPTS) => {
 	for (let i = 0; i < maxAttempts; i++) {
 		if (await isPortAvailable(port)) {
 			Log.info(`Port ${port} is now available`);
@@ -81,12 +81,12 @@ async function waitForPort (port, maxAttempts = PORT_CHECK_MAX_ATTEMPTS) {
 		await new Promise((resolve) => setTimeout(resolve, PORT_CHECK_INTERVAL_MS));
 	}
 	Log.warn(`Port ${port} still not available after ${maxAttempts} attempts`);
-}
+};
 
 /**
  * Start the server process
  */
-function startServer () {
+const startServer = () => {
 	// Start node directly instead of via npm to avoid process tree issues
 	child = spawn("node", ["./serveronly"], {
 		stdio: "inherit",
@@ -113,12 +113,12 @@ function startServer () {
 			Log.error(`Server exited unexpectedly with code ${code} and signal ${signal}`);
 		}
 	});
-}
+};
 
 /**
  * Send reload notification to all connected clients
  */
-function notifyClientsToReload () {
+const notifyClientsToReload = () => {
 	const { port, address } = getServerConfig();
 	const options = {
 		hostname: address,
@@ -139,13 +139,13 @@ function notifyClientsToReload () {
 	});
 
 	req.end();
-}
+};
 
 /**
  * Restart the server process
  * @param {string} reason The reason for the restart
  */
-function restartServer (reason) {
+const restartServer = (reason) => {
 	if (restartTimer) clearTimeout(restartTimer);
 
 	restartTimer = setTimeout(() => {
@@ -174,14 +174,14 @@ function restartServer (reason) {
 			startServer();
 		}
 	}, RESTART_DELAY_MS);
-}
+};
 
 /**
  * Watch a specific file for changes and restart the server on change
  * Watches the parent directory to handle editors that use atomic writes
  * @param {string} file The file path to watch
  */
-function watchFile (file) {
+const watchFile = (file) => {
 	try {
 		const fileName = path.basename(file);
 		const dirName = path.dirname(file);
@@ -207,7 +207,7 @@ function watchFile (file) {
 	} catch (error) {
 		Log.error(`Failed to watch file ${file}:`, error.message);
 	}
-}
+};
 
 startServer();
 
diff --git a/tests/configs/config_functions.js b/tests/configs/config_functions.js
index d4c9689736..d06bc71422 100644
--- a/tests/configs/config_functions.js
+++ b/tests/configs/config_functions.js
@@ -14,7 +14,7 @@ const config = require(`${process.cwd()}/tests/configs/default.js`).configFactor
 							return value;
 						}
 					},
-					roundToInt2: function (value) {
+					roundToInt2: (value) => {
 						try {
 							return Math.round(parseFloat(value));
 						} catch {
diff --git a/tests/e2e/animateCSS_spec.js b/tests/e2e/animateCSS_spec.js
index eed01f4926..ba92c07b1c 100644
--- a/tests/e2e/animateCSS_spec.js
+++ b/tests/e2e/animateCSS_spec.js
@@ -16,11 +16,11 @@ describe("AnimateCSS integration Test", () => {
 	 * Get the compliments container element (waits until available).
 	 * @returns {Promise<void>}
 	 */
-	async function getComplimentsElement () {
+	const getComplimentsElement = async () => {
 		await helpers.getDocument();
 		page = helpers.getPage();
 		await expect(page.locator(".compliments")).toBeVisible();
-	}
+	};
 
 	/**
 	 * Wait for an Animate.css class to appear and persist briefly.
@@ -28,20 +28,20 @@ describe("AnimateCSS integration Test", () => {
 	 * @param {{timeout?: number}} [options] Poll timeout in ms (default 6000)
 	 * @returns {Promise<void>}
 	 */
-	async function waitForAnimationClass (cls, { timeout = 6000 } = {}) {
+	const waitForAnimationClass = async (cls, { timeout = 6000 } = {}) => {
 		const locator = page.locator(`.compliments.animate__animated.${cls}`);
 		await locator.waitFor({ state: "attached", timeout });
 		// small stability wait
 		await new Promise((r) => setTimeout(r, 50));
 		await expect(locator).toBeAttached();
-	}
+	};
 
 	/**
 	 * Assert that no Animate.css animation class is applied within a time window.
 	 * @param {number} [ms] Observation period in ms (default 2000)
 	 * @returns {Promise<void>}
 	 */
-	async function assertNoAnimationWithin (ms = 2000) {
+	const assertNoAnimationWithin = async (ms = 2000) => {
 		const start = Date.now();
 		const locator = page.locator(".compliments.animate__animated");
 		while (Date.now() - start < ms) {
@@ -51,7 +51,7 @@ describe("AnimateCSS integration Test", () => {
 			}
 			await new Promise((r) => setTimeout(r, 100));
 		}
-	}
+	};
 
 	/**
 	 * Run one animation test scenario.
@@ -59,7 +59,7 @@ describe("AnimateCSS integration Test", () => {
 	 * @param {string} [animationOut] Expected animate-out name
 	 * @returns {Promise<void>} Throws on assertion failure
 	 */
-	async function runAnimationTest (animationIn, animationOut) {
+	const runAnimationTest = async (animationIn, animationOut) => {
 		await getComplimentsElement();
 		if (!animationIn && !animationOut) {
 			await assertNoAnimationWithin(2000);
@@ -71,7 +71,7 @@ describe("AnimateCSS integration Test", () => {
 			await new Promise((r) => setTimeout(r, 2100));
 			await waitForAnimationClass(`animate__${animationOut}`);
 		}
-	}
+	};
 
 	afterEach(async () => {
 		await helpers.stopApplication();
diff --git a/tests/e2e/helpers/global-setup.js b/tests/e2e/helpers/global-setup.js
index 3f99721bc5..07f7aa91b7 100644
--- a/tests/e2e/helpers/global-setup.js
+++ b/tests/e2e/helpers/global-setup.js
@@ -27,7 +27,7 @@ let page;
  * Ensure Playwright browser and context are available.
  * @returns {Promise<void>}
  */
-async function ensureContext () {
+const ensureContext = async () => {
 	if (!browser) {
 		// Additional args for CI stability to prevent crashes
 		const launchOptions = {
@@ -45,14 +45,14 @@ async function ensureContext () {
 	if (!context) {
 		context = await browser.newContext();
 	}
-}
+};
 
 /**
  * Open a fresh page pointing to the provided url.
  * @param {string} url target url
  * @returns {Promise<import('playwright').Page>} initialized page instance
  */
-async function openPage (url) {
+const openPage = async (url) => {
 	await ensureContext();
 	if (page) {
 		await page.close();
@@ -60,13 +60,13 @@ async function openPage (url) {
 	page = await context.newPage();
 	await page.goto(url, { waitUntil: "load" });
 	return page;
-}
+};
 
 /**
  * Close page, context and browser if they exist.
  * @returns {Promise<void>}
  */
-async function closeBrowser () {
+const closeBrowser = async () => {
 	if (page) {
 		await page.close();
 		page = null;
@@ -79,7 +79,7 @@ async function closeBrowser () {
 		await browser.close();
 		browser = null;
 	}
-}
+};
 
 exports.getPage = () => {
 	if (!page) {
diff --git a/tests/e2e/helpers/weather-functions.js b/tests/e2e/helpers/weather-functions.js
index 8eb0c0699e..713a4e0636 100644
--- a/tests/e2e/helpers/weather-functions.js
+++ b/tests/e2e/helpers/weather-functions.js
@@ -9,7 +9,7 @@ const helpers = require("./global-setup");
  * @param {object} page - Playwright page
  * @param {string} mockDataFile - Filename of mock data
  */
-async function injectMockWeatherData (page, mockDataFile) {
+const injectMockWeatherData = async (page, mockDataFile) => {
 	const rawData = JSON.parse(fs.readFileSync(path.resolve(__dirname, "../../mocks", mockDataFile)).toString());
 
 	// Validate that the fixture has at least one expected weather data type
@@ -84,7 +84,7 @@ async function injectMockWeatherData (page, mockDataFile) {
 			});
 		}
 	}, { type, data });
-}
+};
 
 exports.startApplication = async (configFileName, mockDataFile) => {
 	await helpers.startApplication(configFileName);
diff --git a/tests/e2e/modules/newsfeed_spec.js b/tests/e2e/modules/newsfeed_spec.js
index 88a6205bfd..615598e531 100644
--- a/tests/e2e/modules/newsfeed_spec.js
+++ b/tests/e2e/modules/newsfeed_spec.js
@@ -193,7 +193,7 @@ describe("Newsfeed module > Notifications", () => {
 		const info = await page.evaluate(() => new Promise((resolve, reject) => {
 			const timer = setTimeout(() => reject(new Error("ARTICLE_INFO_RESPONSE timeout")), 3000);
 			const origSend = MM.sendNotification.bind(MM);
-			MM.sendNotification = function (n, p, s) {
+			MM.sendNotification = (n, p, s) => {
 				if (n === "ARTICLE_INFO_RESPONSE") {
 					clearTimeout(timer);
 					MM.sendNotification = origSend;
diff --git a/tests/e2e/translations_spec.js b/tests/e2e/translations_spec.js
index 93d9a477b6..3e16154312 100644
--- a/tests/e2e/translations_spec.js
+++ b/tests/e2e/translations_spec.js
@@ -14,12 +14,12 @@ const {
  * Create a fresh Translator state for each test.
  * @returns {Promise<object>} Shared Translator singleton with cleared state
  */
-async function getFreshTranslator () {
+const getFreshTranslator = async () => {
 	setupTranslationTestEnvironment(3000);
 	const { Translator } = await import(TRANSLATOR_MODULE_URL);
 	resetTranslatorState(Translator);
 	return Translator;
-}
+};
 
 describe("translations", () => {
 	let server;
diff --git a/tests/electron/helpers/weather-setup.js b/tests/electron/helpers/weather-setup.js
index 3bddaef1a1..05807f82e2 100644
--- a/tests/electron/helpers/weather-setup.js
+++ b/tests/electron/helpers/weather-setup.js
@@ -8,7 +8,7 @@ const helpers = require("./global-setup");
  * This bypasses the weather provider and tests only client-side rendering
  * @param {string} mockDataFile - Filename of mock data in tests/mocks
  */
-async function injectMockWeatherData (mockDataFile) {
+const injectMockWeatherData = async (mockDataFile) => {
 	const rawData = JSON.parse(fs.readFileSync(path.resolve(__dirname, "../../mocks", mockDataFile)).toString());
 
 	const timezoneOffset = rawData.timezone_offset ? rawData.timezone_offset / 60 : 0;
@@ -70,7 +70,7 @@ async function injectMockWeatherData (mockDataFile) {
 			});
 		}
 	}, { type, data });
-}
+};
 
 exports.getText = async (element, result) => {
 	const elem = await helpers.getElement(element);
diff --git a/tests/unit/classes/translator_spec.js b/tests/unit/classes/translator_spec.js
index e50607d711..5a2f6f41d8 100644
--- a/tests/unit/classes/translator_spec.js
+++ b/tests/unit/classes/translator_spec.js
@@ -12,12 +12,12 @@ const {
  * Create a fresh Translator state for each test.
  * @returns {Promise<object>} Shared Translator singleton with cleared state
  */
-async function getFreshTranslator () {
+const getFreshTranslator = async () => {
 	setupTranslationTestEnvironment(3001);
 	const { Translator } = await import(TRANSLATOR_MODULE_URL);
 	resetTranslatorState(Translator);
 	return Translator;
-}
+};
 
 describe("Translator", () => {
 	let server;
diff --git a/tests/unit/functions/ip_access_control_spec.js b/tests/unit/functions/ip_access_control_spec.js
index 2a129fba71..0ac027e899 100644
--- a/tests/unit/functions/ip_access_control_spec.js
+++ b/tests/unit/functions/ip_access_control_spec.js
@@ -6,14 +6,12 @@ import { ipAccessControl, socketIpAccessControl } from "../../../js/ip_access_co
  * Creates a minimal Express-like response mock used by the middleware tests.
  * @returns {{ status: ReturnType<typeof vi.fn>, send: ReturnType<typeof vi.fn> }} Mock response object.
  */
-function createResponseMock () {
-	return {
-		status: vi.fn(function () {
-			return this;
-		}),
-		send: vi.fn()
-	};
-}
+const createResponseMock = () => {
+	const res = {};
+	res.status = vi.fn().mockReturnValue(res);
+	res.send = vi.fn().mockReturnValue(res);
+	return res;
+};
 
 describe("ip_access_control", () => {
 	describe("ipAccessControl", () => {
diff --git a/tests/unit/functions/update_helper_spec.js b/tests/unit/functions/update_helper_spec.js
index 7b7635f47a..f4eb7a742e 100644
--- a/tests/unit/functions/update_helper_spec.js
+++ b/tests/unit/functions/update_helper_spec.js
@@ -29,24 +29,24 @@ describe("UpdateHelper", () => {
 	 * @param {string} moduleName - Name of the module directory to create.
 	 * @returns {{ root: string, modulePath: string }} Created paths.
 	 */
-	function createTempModuleRoot (moduleName) {
+	const createTempModuleRoot = (moduleName) => {
 		const root = mkdtempSync(join(tmpdir(), "mm-updater-"));
 		const modulePath = join(root, "modules", moduleName);
 		mkdirSync(modulePath, { recursive: true });
 		tempRoots.push(root);
 		return { root, modulePath };
-	}
+	};
 
 	/**
 	 * Creates a fresh UpdateHelper instance for testing.
 	 * @param {object} config - Optional config overrides.
 	 * @returns {Promise<object>} Resolved UpdateHelper instance.
 	 */
-	async function createUpdater (config = {}) {
+	const createUpdater = async (config = {}) => {
 		const updateHelperModule = await import("../../../defaultmodules/updatenotification/update_helper");
 		const UpdateHelper = updateHelperModule.default || updateHelperModule;
 		return new UpdateHelper({ updates: [], updateTimeout: 1000, updateAutorestart: false, ...config });
-	}
+	};
 
 	it("marks update as requiring manual restart when autoRestart is disabled", async () => {
 		const moduleName = "MMM-Test";
diff --git a/tests/unit/functions/updatenotification_spec.js b/tests/unit/functions/updatenotification_spec.js
index f72e7ccc63..fb404ad0df 100644
--- a/tests/unit/functions/updatenotification_spec.js
+++ b/tests/unit/functions/updatenotification_spec.js
@@ -7,7 +7,7 @@ import { vi, describe, beforeEach, afterEach, it, expect } from "vitest";
  * @param {{ current: import("vitest").MockInstance | null }} execGitSpyRef reference to the execGit spy.
  * @returns {Promise<unknown>} resolved GitHelper instance.
  */
-async function createGitHelper (fsStatSyncMockRef, loggerMockRef, execGitSpyRef) {
+const createGitHelper = async (fsStatSyncMockRef, loggerMockRef, execGitSpyRef) => {
 	vi.resetModules();
 
 	fsStatSyncMockRef.current = vi.fn();
@@ -26,7 +26,7 @@ async function createGitHelper (fsStatSyncMockRef, loggerMockRef, execGitSpyRef)
 	execGitSpyRef.current = vi.spyOn(instance, "execGit");
 	instance.__loggerMock = loggerMockRef.current;
 	return instance;
-}
+};
 
 describe("Updatenotification", () => {
 	const fsStatSyncMockRef = { current: null };
diff --git a/tests/unit/modules/default/calendar/calendar_fetcher_utils_spec.js b/tests/unit/modules/default/calendar/calendar_fetcher_utils_spec.js
index 657c52eee0..a61017f41b 100644
--- a/tests/unit/modules/default/calendar/calendar_fetcher_utils_spec.js
+++ b/tests/unit/modules/default/calendar/calendar_fetcher_utils_spec.js
@@ -527,7 +527,7 @@ END:VCALENDAR`);
 
 		const yearConfig = { ...defaultConfig, maximumNumberOfDays: 365 };
 
-		const buildEvent = function (rrule, dtstart = "20231002", dtend = "20231003") {
+		const buildEvent = (rrule, dtstart = "20231002", dtend = "20231003") => {
 			return ical.parseICS(`BEGIN:VCALENDAR
 BEGIN:VEVENT
 DTSTART;VALUE=DATE:${dtstart}
diff --git a/tests/unit/modules/default/weather/node_helper_spec.js b/tests/unit/modules/default/weather/node_helper_spec.js
index 81a49b7305..b5d156e9a0 100644
--- a/tests/unit/modules/default/weather/node_helper_spec.js
+++ b/tests/unit/modules/default/weather/node_helper_spec.js
@@ -5,7 +5,7 @@ import { afterEach, describe, expect, it, vi } from "vitest";
  * Creates a fresh weather node helper instance with isolated mocks.
  * @returns {Promise<object>} The mocked weather node helper.
  */
-async function loadWeatherNodeHelper () {
+const loadWeatherNodeHelper = async () => {
 	vi.resetModules();
 
 	const loggerMock = {
@@ -42,7 +42,7 @@ async function loadWeatherNodeHelper () {
 	helper.sendSocketNotification = vi.fn();
 
 	return helper;
-}
+};
 
 afterEach(() => {
 	vi.resetAllMocks();
diff --git a/tests/unit/modules/default/weather/providers/buienradar_spec.js b/tests/unit/modules/default/weather/providers/buienradar_spec.js
index 25366f7c8e..2f57958c4e 100644
--- a/tests/unit/modules/default/weather/providers/buienradar_spec.js
+++ b/tests/unit/modules/default/weather/providers/buienradar_spec.js
@@ -14,7 +14,7 @@ const BUIENRADAR_URL = "https://forecast.buienradar.nl/2.0/forecast/*";
  * Builds a stable Buienradar mock payload for parsing tests.
  * @returns {object} Buienradar forecast response fixture.
  */
-function buildBuienradarResponse () {
+const buildBuienradarResponse = () => {
 	const today = "2100-01-01";
 	const tomorrow = "2100-01-02";
 
@@ -71,7 +71,7 @@ function buildBuienradarResponse () {
 			}
 		]
 	};
-}
+};
 
 let server;
 
diff --git a/tests/unit/modules/default/weather/providers/ukmetofficedatahub_spec.js b/tests/unit/modules/default/weather/providers/ukmetofficedatahub_spec.js
index 7bda9a6b09..397345980d 100644
--- a/tests/unit/modules/default/weather/providers/ukmetofficedatahub_spec.js
+++ b/tests/unit/modules/default/weather/providers/ukmetofficedatahub_spec.js
@@ -19,7 +19,7 @@ const UKMETOFFICE_DAILY_URL = "https://data.hub.api.metoffice.gov.uk/sitespecifi
  * @param {object} source Source UK Met Office daily mock payload.
  * @returns {object} Cloned payload with deterministic future dates in `timeSeries`.
  */
-function withFutureDailyTimes (source) {
+const withFutureDailyTimes = (source) => {
 	const clone = JSON.parse(JSON.stringify(source));
 	const today = new Date();
 	today.setUTCHours(0, 0, 0, 0);
@@ -35,7 +35,7 @@ function withFutureDailyTimes (source) {
 	});
 
 	return clone;
-}
+};
 
 let server;
 
diff --git a/tests/unit/modules/default/weather/providers/weatherapi_spec.js b/tests/unit/modules/default/weather/providers/weatherapi_spec.js
index e53713cc65..5242d2f439 100644
--- a/tests/unit/modules/default/weather/providers/weatherapi_spec.js
+++ b/tests/unit/modules/default/weather/providers/weatherapi_spec.js
@@ -13,7 +13,7 @@ const WEATHER_API_URL = "https://api.weatherapi.com/v1/forecast.json*";
  * Builds a stable WeatherAPI mock payload for current, daily, and hourly parsing tests.
  * @returns {object} WeatherAPI forecast response fixture.
  */
-function buildWeatherApiResponse () {
+const buildWeatherApiResponse = () => {
 	return {
 		location: {
 			name: "Toronto",
@@ -127,7 +127,7 @@ function buildWeatherApiResponse () {
 			]
 		}
 	};
-}
+};
 
 let server;
 
diff --git a/tests/utils/translation_test_environment.js b/tests/utils/translation_test_environment.js
index 8cebb7c53c..e192f25c98 100644
--- a/tests/utils/translation_test_environment.js
+++ b/tests/utils/translation_test_environment.js
@@ -10,7 +10,7 @@ const TRANSLATOR_MODULE_URL = pathToFileURL(path.join(__dirname, "..", "..", "js
  * when additional translation stores are introduced.
  * @param {object} Translator The shared Translator module instance.
  */
-function resetTranslatorState (Translator) {
+const resetTranslatorState = (Translator) => {
 	for (const [key, value] of Object.entries(Translator)) {
 		if (typeof value === "function") {
 			continue;
@@ -20,21 +20,21 @@ function resetTranslatorState (Translator) {
 			Translator[key] = {};
 		}
 	}
-}
+};
 
 /**
  * Set up DOM globals used by translation tests.
  * @param {number} [port] Base URI port used to resolve relative translation paths.
  * @returns {void}
  */
-function setupTranslationTestEnvironment (port = 3000) {
+const setupTranslationTestEnvironment = (port = 3000) => {
 	const dom = new JSDOM("", { url: `http://localhost:${port}` });
 
 	global.document = dom.window.document;
 	if (!global.Log) {
 		global.Log = { log: vi.fn(), error: vi.fn() };
 	}
-}
+};
 
 module.exports = {
 	setupTranslationTestEnvironment,