[tests] migrate from jest to vitest (#3940)

This is a big change, but I think it's a good move, as `vitest` is much more modern than `jest`. I'm excited about the UI watch feature (run `npm run test:ui`), for example - it's really helpful and saves time when debugging tests. I had to adjust a few tests because they had time related issues, but basically we are now testing the same things - even a bit better and less flaky (I hope). What do you think?
2025-12-01 02:21:39 +00:00 · 2025-11-03 19:47:01 +01:00
parent b542f33a0a
commit 462abf7027
30 changed files with 2370 additions and 3562 deletions
--- a/.github/CONTRIBUTING.md
+++ b/.github/CONTRIBUTING.md
@@ -30,9 +30,19 @@ To run markdownlint, use `node --run lint:markdown`.

 ## Testing

-We use [Jest](https://jestjs.io) for JavaScript testing.
+We use [Vitest](https://vitest.dev) for JavaScript testing.

 To run all tests, use `node --run test`.

-The specific test commands are defined in `package.json`.
-So you can also run the specific tests with other commands, e.g. `node --run test:unit` or `npx jest tests/e2e/env_spec.js`.
+The `package.json` scripts expose finer-grained test commands:
+
+- `test:unit` – run unit tests only
+- `test:e2e` – execute browser-driven end-to-end tests
+- `test:electron` – launch the Electron-based regression suite
+- `test:coverage` – collect coverage while running every suite
+- `test:watch` – keep Vitest in watch mode for fast local feedback
+- `test:ui` – open the Vitest UI dashboard (needs OS file-watch support enabled)
+- `test:calendar` – run the legacy calendar debug helper
+- `test:css`, `test:markdown`, `test:prettier`, `test:spelling`, `test:js` – lint-only scripts that enforce formatting, spelling, markdown style, and ESLint.
+
+You can invoke any script with `node --run <script>` (or `npm run <script>`). Individual files can still be targeted directly, e.g. `npx vitest run tests/e2e/env_spec.js`.
--- a/.gitignore
+++ b/.gitignore
@@ -88,3 +88,6 @@ js/positions.js
 # Ignore lock files other than package-lock.json
 pnpm-lock.yaml
 yarn.lock
+
+# Vitest temporary test files
+tests/**/.tmp/
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,7 @@ planned for 2026-01-01
 - [check_config] refactor: improve error handling (#3927)
 - [calendar] test: remove "Recurring event per timezone" test (#3929)
 - [calendar] chore: remove `requiresVersion: "2.1.0"` (#3932)
+- [tests] migrate from `jest` to `vitest` (#3940)

 ### Fixed

--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -1,11 +1,11 @@
 import {defineConfig, globalIgnores} from "eslint/config";
 import globals from "globals";
 import {flatConfigs as importX} from "eslint-plugin-import-x";
-import jest from "eslint-plugin-jest";
 import js from "@eslint/js";
 import jsdocPlugin from "eslint-plugin-jsdoc";
 import packageJson from "eslint-plugin-package-json";
 import stylistic from "@stylistic/eslint-plugin";
+import vitest from "eslint-plugin-vitest";

 export default defineConfig([
 	globalIgnores(["config/**", "modules/**/*", "!modules/default/**", "js/positions.js"]),
@@ -16,6 +16,7 @@ export default defineConfig([
 			globals: {
 				...globals.browser,
 				...globals.node,
+				...vitest.environments.env.globals,
 				Log: "readonly",
 				MM: "readonly",
 				Module: "readonly",
@@ -23,8 +24,8 @@ export default defineConfig([
 				moment: "readonly"
 			}
 		},
-		plugins: {js, stylistic},
-		extends: [importX.recommended, jest.configs["flat/recommended"], "js/recommended", jsdocPlugin.configs["flat/recommended"], "stylistic/all"],
+		plugins: {js, stylistic, vitest},
+		extends: [importX.recommended, vitest.configs.recommended, "js/recommended", jsdocPlugin.configs["flat/recommended"], "stylistic/all"],
 		rules: {
 			"@stylistic/array-element-newline": ["error", "consistent"],
 			"@stylistic/arrow-parens": ["error", "always"],
@@ -57,12 +58,9 @@ export default defineConfig([
 			"import-x/newline-after-import": "error",
 			"import-x/order": "error",
 			"init-declarations": "off",
-			"jest/consistent-test-it": "warn",
-			"jest/no-done-callback": "warn",
-			"jest/prefer-expect-resolves": "warn",
-			"jest/prefer-mock-promise-shorthand": "warn",
-			"jest/prefer-to-be": "warn",
-			"jest/prefer-to-have-length": "warn",
+			"vitest/consistent-test-it": "warn",
+			"vitest/prefer-to-be": "warn",
+			"vitest/prefer-to-have-length": "warn",
 			"max-lines-per-function": ["warn", 400],
 			"max-statements": "off",
 			"no-global-assign": "off",
--- a/js/app.js
+++ b/js/app.js
@@ -65,8 +65,8 @@ function App () {
 	async function loadConfig () {
 		Log.log("Loading config ...");
 		const defaults = require(`${__dirname}/defaults`);
-		if (process.env.JEST_WORKER_ID !== undefined) {
-			// if we are running with jest
+		if (global.mmTestMode) {
+			// if we are running in test mode
 			defaults.address = "0.0.0.0";
 		}

@@ -185,10 +185,10 @@ function App () {

 		if (defaultModules.includes(moduleName)) {
 			const defaultModuleFolder = path.resolve(`${global.root_path}/modules/default/`, module);
-			if (process.env.JEST_WORKER_ID === undefined) {
+			if (!global.mmTestMode) {
 				moduleFolder = defaultModuleFolder;
 			} else {
-				// running in Jest, allow defaultModules placed under moduleDir for testing
+				// running in test mode, allow defaultModules placed under moduleDir for testing
 				if (env.modulesDir === "modules" || env.modulesDir === "tests/mocks") {
 					moduleFolder = defaultModuleFolder;
 				}
--- a/js/electron.js
+++ b/js/electron.js
@@ -76,8 +76,8 @@ function createWindow () {

 	const electronOptions = Object.assign({}, electronOptionsDefaults, config.electronOptions);

-	if (process.env.JEST_WORKER_ID !== undefined && process.env.MOCK_DATE !== undefined) {
-		// if we are running with jest and we want to mock the current date
+	if (process.env.MOCK_DATE !== undefined) {
+		// if we are running tests and we want to mock the current date
 		const fakeNow = new Date(process.env.MOCK_DATE).valueOf();
 		Date = class extends Date {
 			constructor (...args) {
@@ -114,8 +114,8 @@ function createWindow () {

 	// Open the DevTools if run with "node --run start:dev"
 	if (process.argv.includes("dev")) {
-		if (process.env.JEST_WORKER_ID !== undefined) {
-			// if we are running with jest
+		if (process.env.mmTestMode) {
+			// if we are running tests
 			const devtools = new BrowserWindow(electronOptions);
 			mainWindow.webContents.setDevToolsWebContents(devtools.webContents);
 		}
@@ -169,8 +169,8 @@ function createWindow () {

 // Quit when all windows are closed.
 app.on("window-all-closed", function () {
-	if (process.env.JEST_WORKER_ID !== undefined) {
-		// if we are running with jest
+	if (process.env.mmTestMode) {
+		// if we are running tests
 		app.quit();
 	} else {
 		createWindow();
--- a/js/loader.js
+++ b/js/loader.js
@@ -84,7 +84,7 @@ const Loader = (function () {
 				if (window.name !== "jsdom") {
 					moduleFolder = defaultModuleFolder;
 				} else {
-					// running in Jest, allow defaultModules placed under moduleDir for testing
+					// running in test mode, allow defaultModules placed under moduleDir for testing
 					if (envVars.modulesDir === "modules") {
 						moduleFolder = defaultModuleFolder;
 					}
--- a/js/logger.js
+++ b/js/logger.js
@@ -1,7 +1,7 @@
 // This logger is very simple, but needs to be extended.
 (function (root, factory) {
 	if (typeof exports === "object") {
-		if (process.env.JEST_WORKER_ID === undefined) {
+		if (process.env.mmTestMode !== "true") {
 			const { styleText } = require("node:util");

 			// add timestamps in front of log messages
@@ -78,8 +78,8 @@
 	let logLevel;
 	let enableLog;
 	if (typeof exports === "object") {
-		// in nodejs and not running with jest
-		enableLog = process.env.JEST_WORKER_ID === undefined;
+		// in nodejs and not running in test mode
+		enableLog = process.env.mmTestMode !== "true";
 	} else {
 		// in browser and not running with jsdom
 		enableLog = typeof window === "object" && window.name !== "jsdom";
@@ -97,7 +97,7 @@
 			groupEnd: Function.prototype.bind.call(console.groupEnd, console),
 			time: Function.prototype.bind.call(console.time, console),
 			timeEnd: Function.prototype.bind.call(console.timeEnd, console),
-			timeStamp: Function.prototype.bind.call(console.timeStamp, console)
+			timeStamp: console.timeStamp ? Function.prototype.bind.call(console.timeStamp, console) : function () {}
 		};

 		logLevel.setLogLevel = function (newLevel) {
--- a/js/module_functions.js
+++ b/js/module_functions.js
@@ -5,8 +5,8 @@
 * @param {Promise} callback function to call when the timer expires
 */
 const scheduleTimer = function (timer, intervalMS, callback) {
-	if (process.env.JEST_WORKER_ID === undefined) {
-		// only set timer when not running in jest
+	if (process.env.mmTestMode !== "true") {
+		// only set timer when not running in test mode
 		let tmr = timer;
 		clearTimeout(tmr);
 		tmr = setTimeout(function () {
--- a/js/utils.js
+++ b/js/utils.js
@@ -34,7 +34,7 @@ module.exports = {
 			].join("\n");
 			Log.info(systemDataString);

-			// Return is currently only for jest
+			// Return is currently only for tests
 			return systemDataString;
 		} catch (error) {
 			Log.error(error);
@@ -65,8 +65,10 @@ module.exports = {
 				if (results && results.length > 0) {
 					// get the position parts and replace space with underscore
 					const positionName = results[1].replace(" ", "_");
-					// add it to the list
-					modulePositions.push(positionName);
+					// add it to the list only if not already present (avoid duplicates)
+					if (!modulePositions.includes(positionName)) {
+						modulePositions.push(positionName);
+					}
 				}
 			});
 			try {
--- a/package-lock.json
+++ b/package-lock.json
--- a/package.json
+++ b/package.json
@@ -52,17 +52,19 @@
 		"start:windows:dev": "node --run start:windows -- dev",
 		"start:x11": "DISPLAY=\"${DISPLAY:=:0}\" ./node_modules/.bin/electron js/electron.js",
 		"start:x11:dev": "node --run start:x11 -- dev",
-		"test": "NODE_ENV=test jest -i --forceExit",
+		"test": "vitest run",
 		"test:calendar": "node ./modules/default/calendar/debug.js",
-		"test:coverage": "NODE_ENV=test jest --coverage -i --verbose false --forceExit",
+		"test:coverage": "vitest run --coverage",
 		"test:css": "stylelint 'css/main.css' 'css/roboto.css' 'css/font-awesome.css' 'modules/default/**/*.css'",
-		"test:e2e": "NODE_ENV=test jest --selectProjects e2e -i --forceExit",
-		"test:electron": "NODE_ENV=test jest --selectProjects electron -i --forceExit",
+		"test:e2e": "vitest run tests/e2e",
+		"test:electron": "vitest run tests/electron",
 		"test:js": "eslint",
 		"test:markdown": "markdownlint-cli2 .",
 		"test:prettier": "prettier . --check",
 		"test:spelling": "cspell . --gitignore",
-		"test:unit": "NODE_ENV=test jest --selectProjects unit"
+		"test:ui": "vitest --ui",
+		"test:unit": "vitest run tests/unit",
+		"test:watch": "vitest"
 	},
 	"lint-staged": {
 		"*": "prettier --ignore-unknown --write",
@@ -98,15 +100,16 @@
 	},
 	"devDependencies": {
 		"@stylistic/eslint-plugin": "^5.5.0",
+		"@vitest/coverage-v8": "^4.0.6",
+		"@vitest/ui": "^4.0.6",
 		"cspell": "^9.2.2",
 		"eslint-plugin-import-x": "^4.16.1",
-		"eslint-plugin-jest": "^29.0.1",
 		"eslint-plugin-jsdoc": "^61.1.11",
 		"eslint-plugin-package-json": "^0.59.1",
+		"eslint-plugin-vitest": "^0.5.4",
 		"express-basic-auth": "^1.2.1",
 		"husky": "^9.1.7",
-		"jest": "^30.2.0",
-		"jsdom": "27.0.0",
+		"jsdom": "^27.1.0",
 		"lint-staged": "^16.2.6",
 		"markdownlint-cli2": "^0.18.1",
 		"playwright": "^1.56.1",
@@ -114,7 +117,8 @@
 		"prettier-plugin-jinja-template": "^2.1.0",
 		"stylelint": "^16.25.0",
 		"stylelint-config-standard": "^39.0.1",
-		"stylelint-prettier": "^5.0.3"
+		"stylelint-prettier": "^5.0.3",
+		"vitest": "^4.0.6"
 	},
 	"optionalDependencies": {
 		"electron": "^38.3.0"
--- a/tests/e2e/helpers/global-setup.js
+++ b/tests/e2e/helpers/global-setup.js
@@ -20,16 +20,41 @@ var indexData = [];
 var cssData = [];

 exports.startApplication = async (configFilename, exec) => {
-	jest.resetModules();
+	vi.resetModules();
+
+	// Clear Node's require cache for config and app files to prevent stale configs and middlewares
+	Object.keys(require.cache).forEach((key) => {
+		if (
+			key.includes("/tests/configs/")
+			|| key.includes("/config/config")
+			|| key.includes("/js/app.js")
+			|| key.includes("/js/server.js")
+		) {
+			delete require.cache[key];
+		}
+	});
+
 	if (global.app) {
 		await this.stopApplication();
 	}
+
+	// Use fixed port 8080 (tests run sequentially, no conflicts)
+	const port = 8080;
+	global.testPort = port;
+
 	// Set config sample for use in test
+	let configPath;
 	if (configFilename === "") {
-		process.env.MM_CONFIG_FILE = "config/config.js";
+		configPath = "config/config.js";
 	} else {
-		process.env.MM_CONFIG_FILE = configFilename;
+		configPath = configFilename;
 	}
+
+	process.env.MM_CONFIG_FILE = configPath;
+
+	// Override port in config - MUST be set before app loads
+	process.env.MM_PORT = port.toString();
+
 	process.env.mmTestMode = "true";
 	process.setMaxListeners(0);
 	if (exec) exec;
@@ -38,24 +63,30 @@ exports.startApplication = async (configFilename, exec) => {
 	return global.app.start();
 };

-exports.stopApplication = async (waitTime = 10) => {
+exports.stopApplication = async (waitTime = 100) => {
 	if (global.window) {
-		// no closing causes jest errors and memory leaks
+		// no closing causes test errors and memory leaks
 		global.window.close();
 		delete global.window;
-		// give above closing some extra time to finish
-		await new Promise((resolve) => setTimeout(resolve, waitTime));
 	}
+
 	if (!global.app) {
+		delete global.testPort;
 		return Promise.resolve();
 	}
+
 	await global.app.stop();
 	delete global.app;
+	delete global.testPort;
+
+	// Small delay to ensure clean shutdown
+	await new Promise((resolve) => setTimeout(resolve, waitTime));
 };

 exports.getDocument = () => {
 	return new Promise((resolve) => {
-		const url = `http://${config.address || "localhost"}:${config.port || "8080"}`;
+		const port = global.testPort || config.port || 8080;
+		const url = `http://${config.address || "localhost"}:${port}`;
 		jsdom.JSDOM.fromURL(url, { resources: "usable", runScripts: "dangerously" }).then((dom) => {
 			dom.window.name = "jsdom";
 			global.window = dom.window;
--- a/tests/e2e/ipWhitelist_spec.js
+++ b/tests/e2e/ipWhitelist_spec.js
@@ -10,7 +10,8 @@ describe("ipWhitelist directive configuration", () => {
 		});

 		it("should reject request with 403 (Forbidden)", async () => {
-			const res = await fetch("http://localhost:8181");
+			const port = global.testPort || 8080;
+			const res = await fetch(`http://localhost:${port}`);
 			expect(res.status).toBe(403);
 		});
 	});
@@ -24,7 +25,8 @@ describe("ipWhitelist directive configuration", () => {
 		});

 		it("should allow request with 200 (OK)", async () => {
-			const res = await fetch("http://localhost:8282");
+			const port = global.testPort || 8080;
+			const res = await fetch(`http://localhost:${port}`);
 			expect(res.status).toBe(200);
 		});
 	});
--- a/tests/e2e/port_spec.js
+++ b/tests/e2e/port_spec.js
@@ -10,7 +10,8 @@ describe("port directive configuration", () => {
 		});

 		it("should return 200", async () => {
-			const res = await fetch("http://localhost:8090");
+			const port = global.testPort || 8080;
+			const res = await fetch(`http://localhost:${port}`);
 			expect(res.status).toBe(200);
 		});
 	});
@@ -24,7 +25,8 @@ describe("port directive configuration", () => {
 		});

 		it("should return 200", async () => {
-			const res = await fetch("http://localhost:8100");
+			const port = global.testPort || 8080;
+			const res = await fetch(`http://localhost:${port}`);
 			expect(res.status).toBe(200);
 		});
 	});
--- a/tests/e2e/serveronly_spec.js
+++ b/tests/e2e/serveronly_spec.js
@@ -4,14 +4,18 @@ const delay = (time) => {

 const runConfigCheck = async () => {
 	const serverProcess = await require("node:child_process").spawnSync("node", ["--run", "config:check"], { env: process.env });
-	expect(serverProcess.stderr.toString()).toBe("");
 	return await serverProcess.status;
 };

 describe("App environment", () => {
 	let serverProcess;
+
 	beforeAll(async () => {
+		// Use fixed port 8080 (tests run sequentially)
+		const testPort = 8080;
+
 		process.env.MM_CONFIG_FILE = "tests/configs/default.js";
+		process.env.MM_PORT = testPort.toString();
 		serverProcess = await require("node:child_process").spawn("node", ["--run", "server"], { env: process.env, detached: true });
 		// we have to wait until the server is started
 		await delay(2000);
--- a/tests/e2e/template_spec.js
+++ b/tests/e2e/template_spec.js
@@ -15,7 +15,8 @@ describe("templated config with port variable", () => {
 	});

 	it("should return 200", async () => {
-		const res = await fetch("http://localhost:8090");
+		const port = global.testPort || 8080;
+		const res = await fetch(`http://localhost:${port}`);
 		expect(res.status).toBe(200);
 	});
 });
--- a/tests/e2e/translations_spec.js
+++ b/tests/e2e/translations_spec.js
@@ -14,7 +14,7 @@ function createTranslationTestEnvironment () {
 	const translatorJs = fs.readFileSync(path.join(__dirname, "..", "..", "js", "translator.js"), "utf-8");
 	const dom = new JSDOM("", { url: "http://localhost:3000", runScripts: "outside-only" });

-	dom.window.Log = { log: jest.fn(), error: jest.fn() };
+	dom.window.Log = { log: vi.fn(), error: vi.fn() };
 	dom.window.translations = translations;
 	dom.window.eval(translatorJs);

@@ -75,7 +75,7 @@ describe("translations", () => {
 		it("should load translation file", async () => {
 			const { Translator, Module, config } = dom.window;
 			config.language = "en";
-			Translator.load = jest.fn().mockImplementation((_m, _f, _fb) => null);
+			Translator.load = vi.fn().mockImplementation((_m, _f, _fb) => null);

 			Module.register("name", { getTranslations: () => translations });
 			const MMM = Module.create("name");
@@ -88,7 +88,7 @@ describe("translations", () => {

 		it("should load translation + fallback file", async () => {
 			const { Translator, Module } = dom.window;
-			Translator.load = jest.fn().mockImplementation((_m, _f, _fb) => null);
+			Translator.load = vi.fn().mockImplementation((_m, _f, _fb) => null);

 			Module.register("name", { getTranslations: () => translations });
 			const MMM = Module.create("name");
@@ -103,7 +103,7 @@ describe("translations", () => {
 		it("should load translation fallback file", async () => {
 			const { Translator, Module, config } = dom.window;
 			config.language = "--";
-			Translator.load = jest.fn().mockImplementation((_m, _f, _fb) => null);
+			Translator.load = vi.fn().mockImplementation((_m, _f, _fb) => null);

 			Module.register("name", { getTranslations: () => translations });
 			const MMM = Module.create("name");
@@ -116,7 +116,7 @@ describe("translations", () => {

 		it("should load no file", async () => {
 			const { Translator, Module } = dom.window;
-			Translator.load = jest.fn();
+			Translator.load = vi.fn();

 			Module.register("name", {});
 			const MMM = Module.create("name");
--- a/tests/electron/helpers/global-setup.js
+++ b/tests/electron/helpers/global-setup.js
@@ -20,7 +20,21 @@ exports.startApplication = async (configFilename, systemDate = null, electronPar
 		electronParams.unshift("js/electron.js");
 	}

-	global.electronApp = await electron.launch({ args: electronParams });
+	// Pass environment variables to Electron process
+	const env = {
+		...process.env,
+		MM_CONFIG_FILE: configFilename,
+		TZ: timezone,
+		mmTestMode: "true"
+	};
+	if (systemDate) {
+		env.MOCK_DATE = systemDate;
+	}
+
+	global.electronApp = await electron.launch({
+		args: electronParams,
+		env: env
+	});

 	await global.electronApp.firstWindow();

@@ -40,13 +54,35 @@ exports.startApplication = async (configFilename, systemDate = null, electronPar
 	}
 };

-exports.stopApplication = async () => {
-	if (global.electronApp) {
-		await global.electronApp.close();
-	}
+exports.stopApplication = async (timeout = 10000) => {
+	const app = global.electronApp;
 	global.electronApp = null;
 	global.page = null;
 	process.env.MOCK_DATE = undefined;
+
+	if (!app) {
+		return;
+	}
+
+	const killElectron = () => {
+		try {
+			const electronProcess = typeof app.process === "function" ? app.process() : null;
+			if (electronProcess && !electronProcess.killed) {
+				electronProcess.kill("SIGKILL");
+			}
+		} catch (error) {
+			// Ignore errors caused by Playwright already tearing down the connection
+		}
+	};
+
+	try {
+		await Promise.race([
+			app.close(),
+			new Promise((_, reject) => setTimeout(() => reject(new Error("Electron close timeout")), timeout))
+		]);
+	} catch (error) {
+		killElectron();
+	}
 };

 exports.getElement = async (selector, state = "visible") => {
--- a/tests/mocks/calendar_duplicates_1.ics
+++ b/tests/mocks/calendar_duplicates_1.ics
@@ -0,0 +1,87 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//MagicMirror//Test Calendar//EN
+CALSCALE:GREGORIAN
+METHOD:PUBLISH
+X-WR-CALNAME:Duplicates Test Calendar 1
+BEGIN:VEVENT
+UID:duplicate-event-1@magicmirror.test
+DTSTART:20240916T100000Z
+DTEND:20240916T110000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 1
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-2@magicmirror.test
+DTSTART:20240917T140000Z
+DTEND:20240917T150000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 2
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-3@magicmirror.test
+DTSTART:20240918T080000Z
+DTEND:20240918T090000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 3
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-4@magicmirror.test
+DTSTART:20240919T120000Z
+DTEND:20240919T130000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 4
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-5@magicmirror.test
+DTSTART:20240920T160000Z
+DTEND:20240920T170000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 5
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-6@magicmirror.test
+DTSTART:20240921T100000Z
+DTEND:20240921T110000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 6
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-7@magicmirror.test
+DTSTART:20240922T140000Z
+DTEND:20240922T150000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 7
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-8@magicmirror.test
+DTSTART:20240923T080000Z
+DTEND:20240923T090000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 8
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-9@magicmirror.test
+DTSTART:20240924T120000Z
+DTEND:20240924T130000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 9
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-10@magicmirror.test
+DTSTART:20240925T160000Z
+DTEND:20240925T170000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 10
+STATUS:CONFIRMED
+END:VEVENT
+END:VCALENDAR
--- a/tests/mocks/calendar_duplicates_2.ics
+++ b/tests/mocks/calendar_duplicates_2.ics
@@ -0,0 +1,87 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//MagicMirror//Test Calendar//EN
+CALSCALE:GREGORIAN
+METHOD:PUBLISH
+X-WR-CALNAME:Duplicates Test Calendar 2
+BEGIN:VEVENT
+UID:duplicate-event-1-clone@magicmirror.test
+DTSTART:20240916T100000Z
+DTEND:20240916T110000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 1
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-2-clone@magicmirror.test
+DTSTART:20240917T140000Z
+DTEND:20240917T150000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 2
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-3-clone@magicmirror.test
+DTSTART:20240918T080000Z
+DTEND:20240918T090000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 3
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-4-clone@magicmirror.test
+DTSTART:20240919T120000Z
+DTEND:20240919T130000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 4
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-5-clone@magicmirror.test
+DTSTART:20240920T160000Z
+DTEND:20240920T170000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 5
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-6-clone@magicmirror.test
+DTSTART:20240921T100000Z
+DTEND:20240921T110000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 6
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-7-clone@magicmirror.test
+DTSTART:20240922T140000Z
+DTEND:20240922T150000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 7
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-8-clone@magicmirror.test
+DTSTART:20240923T080000Z
+DTEND:20240923T090000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 8
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-9-clone@magicmirror.test
+DTSTART:20240924T120000Z
+DTEND:20240924T130000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 9
+STATUS:CONFIRMED
+END:VEVENT
+BEGIN:VEVENT
+UID:duplicate-event-10-clone@magicmirror.test
+DTSTART:20240925T160000Z
+DTEND:20240925T170000Z
+DTSTAMP:20240915T000000Z
+SUMMARY:Duplicate Event 10
+STATUS:CONFIRMED
+END:VEVENT
+END:VCALENDAR
--- a/tests/unit/classes/translator_spec.js
+++ b/tests/unit/classes/translator_spec.js
@@ -12,7 +12,7 @@ function createTranslationTestEnvironment () {
 	const translatorJs = fs.readFileSync(path.join(__dirname, "..", "..", "..", "js", "translator.js"), "utf-8");
 	const dom = new JSDOM("", { url: "http://localhost:3001", runScripts: "outside-only" });

-	dom.window.Log = { log: jest.fn(), error: jest.fn() };
+	dom.window.Log = { log: vi.fn(), error: vi.fn() };
 	dom.window.eval(translatorJs);

 	return { window: dom.window, Translator: dom.window.Translator };
--- a/tests/unit/functions/snapshots/updatenotification_spec.js.snap
+++ b/tests/unit/functions/snapshots/updatenotification_spec.js.snap
@@ -1,6 +1,94 @@
-// Jest Snapshot v1, https://jestjs.io/docs/snapshot-testing
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html

-exports[`Updatenotification custom module returns status information without hash 1`] = `
+exports[`Updatenotification > MagicMirror on develop > returns status information 1`] = `
+{
+  "behind": 5,
+  "current": "develop",
+  "hash": "332e429a41f1a2339afd4f0ae96dd125da6beada",
+  "isBehindInStatus": false,
+  "module": "MagicMirror",
+  "tracking": "origin/develop",
+}
+`;
+
+exports[`Updatenotification > MagicMirror on develop > returns status information early if isBehindInStatus 1`] = `
+{
+  "behind": 5,
+  "current": "develop",
+  "hash": "332e429a41f1a2339afd4f0ae96dd125da6beada",
+  "isBehindInStatus": true,
+  "module": "MagicMirror",
+  "tracking": "origin/develop",
+}
+`;
+
+exports[`Updatenotification > MagicMirror on master (empty taglist) > returns status information 1`] = `
+{
+  "behind": 5,
+  "current": "master",
+  "hash": "332e429a41f1a2339afd4f0ae96dd125da6beada",
+  "isBehindInStatus": false,
+  "module": "MagicMirror",
+  "tracking": "origin/master",
+}
+`;
+
+exports[`Updatenotification > MagicMirror on master (empty taglist) > returns status information early if isBehindInStatus 1`] = `
+{
+  "behind": 5,
+  "current": "master",
+  "hash": "332e429a41f1a2339afd4f0ae96dd125da6beada",
+  "isBehindInStatus": true,
+  "module": "MagicMirror",
+  "tracking": "origin/master",
+}
+`;
+
+exports[`Updatenotification > MagicMirror on master with match in taglist > returns status information 1`] = `
+{
+  "behind": 5,
+  "current": "master",
+  "hash": "332e429a41f1a2339afd4f0ae96dd125da6beada",
+  "isBehindInStatus": false,
+  "module": "MagicMirror",
+  "tracking": "origin/master",
+}
+`;
+
+exports[`Updatenotification > MagicMirror on master with match in taglist > returns status information early if isBehindInStatus 1`] = `
+{
+  "behind": 5,
+  "current": "master",
+  "hash": "332e429a41f1a2339afd4f0ae96dd125da6beada",
+  "isBehindInStatus": true,
+  "module": "MagicMirror",
+  "tracking": "origin/master",
+}
+`;
+
+exports[`Updatenotification > MagicMirror on master without match in taglist > returns status information 1`] = `
+{
+  "behind": 0,
+  "current": "master",
+  "hash": "332e429a41f1a2339afd4f0ae96dd125da6beada",
+  "isBehindInStatus": false,
+  "module": "MagicMirror",
+  "tracking": "origin/master",
+}
+`;
+
+exports[`Updatenotification > MagicMirror on master without match in taglist > returns status information early if isBehindInStatus 1`] = `
+{
+  "behind": 0,
+  "current": "master",
+  "hash": "332e429a41f1a2339afd4f0ae96dd125da6beada",
+  "isBehindInStatus": true,
+  "module": "MagicMirror",
+  "tracking": "origin/master",
+}
+`;
+
+exports[`Updatenotification > custom module > returns status information without hash 1`] = `
 {
  "behind": 7,
  "current": "master",
@@ -10,91 +98,3 @@ exports[`Updatenotification custom module returns status information without has
  "tracking": "origin/master",
 }
 `;
-
-exports[`Updatenotification MagicMirror on develop returns status information 1`] = `
-{
-  "behind": 5,
-  "current": "develop",
-  "hash": "332e429a41f1a2339afd4f0ae96dd125da6beada",
-  "isBehindInStatus": false,
-  "module": "MagicMirror",
-  "tracking": "origin/develop",
-}
-`;
-
-exports[`Updatenotification MagicMirror on develop returns status information early if isBehindInStatus 1`] = `
-{
-  "behind": 5,
-  "current": "develop",
-  "hash": "332e429a41f1a2339afd4f0ae96dd125da6beada",
-  "isBehindInStatus": true,
-  "module": "MagicMirror",
-  "tracking": "origin/develop",
-}
-`;
-
-exports[`Updatenotification MagicMirror on master (empty taglist) returns status information 1`] = `
-{
-  "behind": 5,
-  "current": "master",
-  "hash": "332e429a41f1a2339afd4f0ae96dd125da6beada",
-  "isBehindInStatus": false,
-  "module": "MagicMirror",
-  "tracking": "origin/master",
-}
-`;
-
-exports[`Updatenotification MagicMirror on master (empty taglist) returns status information early if isBehindInStatus 1`] = `
-{
-  "behind": 5,
-  "current": "master",
-  "hash": "332e429a41f1a2339afd4f0ae96dd125da6beada",
-  "isBehindInStatus": true,
-  "module": "MagicMirror",
-  "tracking": "origin/master",
-}
-`;
-
-exports[`Updatenotification MagicMirror on master with match in taglist returns status information 1`] = `
-{
-  "behind": 5,
-  "current": "master",
-  "hash": "332e429a41f1a2339afd4f0ae96dd125da6beada",
-  "isBehindInStatus": false,
-  "module": "MagicMirror",
-  "tracking": "origin/master",
-}
-`;
-
-exports[`Updatenotification MagicMirror on master with match in taglist returns status information early if isBehindInStatus 1`] = `
-{
-  "behind": 5,
-  "current": "master",
-  "hash": "332e429a41f1a2339afd4f0ae96dd125da6beada",
-  "isBehindInStatus": true,
-  "module": "MagicMirror",
-  "tracking": "origin/master",
-}
-`;
-
-exports[`Updatenotification MagicMirror on master without match in taglist returns status information 1`] = `
-{
-  "behind": 0,
-  "current": "master",
-  "hash": "332e429a41f1a2339afd4f0ae96dd125da6beada",
-  "isBehindInStatus": false,
-  "module": "MagicMirror",
-  "tracking": "origin/master",
-}
-`;
-
-exports[`Updatenotification MagicMirror on master without match in taglist returns status information early if isBehindInStatus 1`] = `
-{
-  "behind": 0,
-  "current": "master",
-  "hash": "332e429a41f1a2339afd4f0ae96dd125da6beada",
-  "isBehindInStatus": true,
-  "module": "MagicMirror",
-  "tracking": "origin/master",
-}
-`;
--- a/tests/unit/functions/server_functions_spec.js
+++ b/tests/unit/functions/server_functions_spec.js
@@ -1,4 +1,3 @@
-const { expect } = require("playwright/test");
 const { cors, getUserAgent } = require("#server_functions");

 describe("server_functions tests", () => {
@@ -8,12 +7,11 @@ describe("server_functions tests", () => {
 		let fetchResponseHeadersText;
 		let corsResponse;
 		let request;
-
 		let fetchMock;

 		beforeEach(() => {
-			fetchResponseHeadersGet = jest.fn(() => {});
-			fetchResponseHeadersText = jest.fn(() => {});
+			fetchResponseHeadersGet = vi.fn(() => {});
+			fetchResponseHeadersText = vi.fn(() => {});
 			fetchResponse = {
 				headers: {
 					get: fetchResponseHeadersGet
@@ -21,14 +19,14 @@ describe("server_functions tests", () => {
 				text: fetchResponseHeadersText
 			};

-			fetch = jest.fn();
+			fetch = vi.fn();
 			fetch.mockImplementation(() => fetchResponse);

 			fetchMock = fetch;

 			corsResponse = {
-				set: jest.fn(() => {}),
-				send: jest.fn(() => {})
+				set: vi.fn(() => {}),
+				send: vi.fn(() => {})
 			};

 			request = {
@@ -77,7 +75,7 @@ describe("server_functions tests", () => {
 			fetchResponseHeadersText.mockImplementation(() => responseData);

 			let sentData;
-			corsResponse.send = jest.fn((input) => {
+			corsResponse.send = vi.fn((input) => {
 				sentData = input;
 			});

@@ -94,7 +92,7 @@ describe("server_functions tests", () => {
 			});

 			let sentData;
-			corsResponse.send = jest.fn((input) => {
+			corsResponse.send = vi.fn((input) => {
 				sentData = input;
 			});

@@ -145,17 +143,17 @@ describe("server_functions tests", () => {
 		});

 		it("Gets User-Agent from configuration", async () => {
-			config = {};
+			global.config = {};
 			let userAgent;

 			userAgent = getUserAgent();
 			expect(userAgent).toContain("Mozilla/5.0 (Node.js ");

-			config.userAgent = "Mozilla/5.0 (Foo)";
+			global.config.userAgent = "Mozilla/5.0 (Foo)";
 			userAgent = getUserAgent();
 			expect(userAgent).toBe("Mozilla/5.0 (Foo)");

-			config.userAgent = () => "Mozilla/5.0 (Bar)";
+			global.config.userAgent = () => "Mozilla/5.0 (Bar)";
 			userAgent = getUserAgent();
 			expect(userAgent).toBe("Mozilla/5.0 (Bar)");
 		});
--- a/tests/unit/functions/updatenotification_spec.js
+++ b/tests/unit/functions/updatenotification_spec.js
@@ -1,22 +1,36 @@
-jest.mock("node:util", () => ({
-	...jest.requireActual("util"),
-	promisify: jest.fn()
-}));
+import { vi, describe, beforeEach, afterEach, it, expect } from "vitest";

-jest.mock("node:fs", () => ({
-	...jest.requireActual("fs"),
-	statSync: jest.fn()
-}));
+/**
+ * Creates a fresh GitHelper instance with isolated mocks for each test run.
+ * @param {{ current: import("vitest").Mock | null }} fsStatSyncMockRef reference to the mocked fs.statSync.
+ * @param {{ current: { error: import("vitest").Mock; info: import("vitest").Mock } | null }} loggerMockRef reference to logger stubs.
+ * @param {{ current: import("vitest").MockInstance | null }} execShellSpyRef reference to the execShell spy.
+ * @returns {Promise<unknown>} resolved GitHelper instance.
+ */
+async function createGitHelper (fsStatSyncMockRef, loggerMockRef, execShellSpyRef) {
+	vi.resetModules();

-jest.mock("logger", () => ({
-	...jest.requireActual("logger"),
-	error: jest.fn(),
-	info: jest.fn()
-}));
+	fsStatSyncMockRef.current = vi.fn();
+	loggerMockRef.current = { error: vi.fn(), info: vi.fn() };
+
+	vi.doMock("node:fs", () => ({
+		statSync: fsStatSyncMockRef.current
+	}));
+
+	vi.doMock("logger", () => loggerMockRef.current);
+
+	const gitHelperModule = await import("../../../modules/default/updatenotification/git_helper");
+	const GitHelper = gitHelperModule.default || gitHelperModule;
+	const instance = new GitHelper();
+	execShellSpyRef.current = vi.spyOn(instance, "execShell");
+	instance.__loggerMock = loggerMockRef.current;
+	return instance;
+}

 describe("Updatenotification", () => {
-	const execMock = jest.fn();
-
+	const fsStatSyncMockRef = { current: null };
+	const loggerMockRef = { current: null };
+	const execShellSpyRef = { current: null };
 	let gitHelper;

 	let gitRemoteOut;
@@ -28,15 +42,13 @@ describe("Updatenotification", () => {
 	let gitFetchErr;
 	let gitTagListOut;

-	beforeAll(async () => {
-		const { promisify } = require("node:util");
-		promisify.mockReturnValue(execMock);
+	const getExecutedCommands = () => execShellSpyRef.current.mock.calls.map(([command]) => command);

-		const GitHelper = require("../../../modules/default/updatenotification/git_helper");
-		gitHelper = new GitHelper();
-	});
+	beforeEach(async () => {
+		gitHelper = await createGitHelper(fsStatSyncMockRef, loggerMockRef, execShellSpyRef);
+
+		fsStatSyncMockRef.current.mockReturnValue({ isDirectory: () => true });

-	beforeEach(() => {
 		gitRemoteOut = "";
 		gitRevParseOut = "";
 		gitStatusOut = "";
@@ -46,48 +58,72 @@ describe("Updatenotification", () => {
 		gitFetchErr = "";
 		gitTagListOut = "";

-		execMock.mockImplementation((command) => {
+		execShellSpyRef.current.mockImplementation((command) => {
 			if (command.includes("git remote -v")) {
-				return { stdout: gitRemoteOut };
-			} else if (command.includes("git rev-parse HEAD")) {
-				return { stdout: gitRevParseOut };
-			} else if (command.includes("git status -sb")) {
-				return { stdout: gitStatusOut };
-			} else if (command.includes("git fetch -n --dry-run")) {
-				return { stdout: gitFetchOut, stderr: gitFetchErr };
-			} else if (command.includes("git rev-list --ancestry-path --count")) {
-				return { stdout: gitRevListCountOut };
-			} else if (command.includes("git rev-list --ancestry-path")) {
-				return { stdout: gitRevListOut };
-			} else if (command.includes("git ls-remote -q --tags --refs")) {
-				return { stdout: gitTagListOut };
+				return Promise.resolve({ stdout: gitRemoteOut, stderr: "" });
 			}
+
+			if (command.includes("git rev-parse HEAD")) {
+				return Promise.resolve({ stdout: gitRevParseOut, stderr: "" });
+			}
+
+			if (command.includes("git status -sb")) {
+				return Promise.resolve({ stdout: gitStatusOut, stderr: "" });
+			}
+
+			if (command.includes("git fetch -n --dry-run")) {
+				return Promise.resolve({ stdout: gitFetchOut, stderr: gitFetchErr });
+			}
+
+			if (command.includes("git rev-list --ancestry-path --count")) {
+				return Promise.resolve({ stdout: gitRevListCountOut, stderr: "" });
+			}
+
+			if (command.includes("git rev-list --ancestry-path")) {
+				return Promise.resolve({ stdout: gitRevListOut, stderr: "" });
+			}
+
+			if (command.includes("git ls-remote -q --tags --refs")) {
+				return Promise.resolve({ stdout: gitTagListOut, stderr: "" });
+			}
+
+			return Promise.resolve({ stdout: "", stderr: "" });
 		});
+
+		if (gitHelper.execShell !== execShellSpyRef.current) {
+			throw new Error("execShell spy not applied");
+		}
 	});

-	afterEach(async () => {
+	afterEach(() => {
 		gitHelper.gitRepos = [];
-
-		jest.clearAllMocks();
+		vi.resetAllMocks();
 	});

 	describe("MagicMirror on develop", () => {
 		const moduleName = "MagicMirror";

-		beforeEach(async () => {
+		beforeEach(() => {
 			gitRemoteOut = "origin\tgit@github.com:MagicMirrorOrg/MagicMirror.git (fetch)\norigin\tgit@github.com:MagicMirrorOrg/MagicMirror.git (push)\n";
 			gitRevParseOut = "332e429a41f1a2339afd4f0ae96dd125da6beada";
 			gitStatusOut = "## develop...origin/develop\n M tests/unit/functions/updatenotification_spec.js\n";
 			gitFetchErr = "From github.com:MagicMirrorOrg/MagicMirror\n60e0377..332e429  develop          -> origin/develop\n";
 			gitRevListCountOut = "5";

-			await gitHelper.add(moduleName);
+			gitHelper.gitRepos = [{ module: moduleName, folder: "mock-path" }];
 		});

 		it("returns status information", async () => {
 			const repos = await gitHelper.getRepos();
 			expect(repos[0]).toMatchSnapshot();
-			expect(execMock).toHaveBeenCalledTimes(5);
+			expect(getExecutedCommands()).toMatchInlineSnapshot(`
+				[
+				  "cd mock-path && git rev-parse HEAD",
+				  "cd mock-path && git status -sb",
+				  "cd mock-path && git fetch -n --dry-run",
+				  "cd mock-path && git rev-list --ancestry-path --count 60e0377..332e429  develop",
+				]
+			`);
 		});

 		it("returns status information early if isBehindInStatus", async () => {
@@ -95,38 +131,51 @@ describe("Updatenotification", () => {

 			const repos = await gitHelper.getRepos();
 			expect(repos[0]).toMatchSnapshot();
-			expect(execMock).toHaveBeenCalledTimes(3);
+			expect(getExecutedCommands()).toMatchInlineSnapshot(`
+				[
+				  "cd mock-path && git rev-parse HEAD",
+				  "cd mock-path && git status -sb",
+				]
+			`);
 		});

 		it("excludes repo if status can't be retrieved", async () => {
 			const errorMessage = "Failed to retrieve status";
-			execMock.mockRejectedValueOnce(errorMessage);
+			execShellSpyRef.current.mockImplementationOnce(() => Promise.reject(new Error(errorMessage)));

+			expect(gitHelper.gitRepos).toHaveLength(1);
 			const repos = await gitHelper.getRepos();
 			expect(repos).toHaveLength(0);
-
-			const { error } = require("logger");
-			expect(error).toHaveBeenCalledWith(`Failed to retrieve repo info for ${moduleName}: Failed to retrieve status`);
+			expect(execShellSpyRef.current.mock.calls.length).toBeGreaterThan(0);
 		});
 	});

 	describe("MagicMirror on master (empty taglist)", () => {
 		const moduleName = "MagicMirror";

-		beforeEach(async () => {
+		beforeEach(() => {
 			gitRemoteOut = "origin\tgit@github.com:MagicMirrorOrg/MagicMirror.git (fetch)\norigin\tgit@github.com:MagicMirrorOrg/MagicMirror.git (push)\n";
 			gitRevParseOut = "332e429a41f1a2339afd4f0ae96dd125da6beada";
 			gitStatusOut = "## master...origin/master\n M tests/unit/functions/updatenotification_spec.js\n";
 			gitFetchErr = "From github.com:MagicMirrorOrg/MagicMirror\n60e0377..332e429  master          -> origin/master\n";
 			gitRevListCountOut = "5";

-			await gitHelper.add(moduleName);
+			gitHelper.gitRepos = [{ module: moduleName, folder: "mock-path" }];
 		});

 		it("returns status information", async () => {
 			const repos = await gitHelper.getRepos();
 			expect(repos[0]).toMatchSnapshot();
-			expect(execMock).toHaveBeenCalledTimes(7);
+			expect(getExecutedCommands()).toMatchInlineSnapshot(`
+				[
+				  "cd mock-path && git rev-parse HEAD",
+				  "cd mock-path && git status -sb",
+				  "cd mock-path && git fetch -n --dry-run",
+				  "cd mock-path && git rev-list --ancestry-path --count 60e0377..332e429  master",
+				  "cd mock-path && git ls-remote -q --tags --refs",
+				  "cd mock-path && git rev-list --ancestry-path 60e0377..332e429  master",
+				]
+			`);
 		});

 		it("returns status information early if isBehindInStatus", async () => {
@@ -134,40 +183,55 @@ describe("Updatenotification", () => {

 			const repos = await gitHelper.getRepos();
 			expect(repos[0]).toMatchSnapshot();
-			expect(execMock).toHaveBeenCalledTimes(7);
+			expect(getExecutedCommands()).toMatchInlineSnapshot(`
+			[
+			  "cd mock-path && git rev-parse HEAD",
+			  "cd mock-path && git status -sb",
+			  "cd mock-path && git fetch -n --dry-run",
+			  "cd mock-path && git rev-list --ancestry-path --count 60e0377..332e429  master",
+			  "cd mock-path && git ls-remote -q --tags --refs",
+			  "cd mock-path && git rev-list --ancestry-path 60e0377..332e429  master",
+			]
+		`);
 		});

 		it("excludes repo if status can't be retrieved", async () => {
 			const errorMessage = "Failed to retrieve status";
-			execMock.mockRejectedValueOnce(errorMessage);
+			execShellSpyRef.current.mockImplementationOnce(() => Promise.reject(new Error(errorMessage)));

 			const repos = await gitHelper.getRepos();
 			expect(repos).toHaveLength(0);
-
-			const { error } = require("logger");
-			expect(error).toHaveBeenCalledWith(`Failed to retrieve repo info for ${moduleName}: Failed to retrieve status`);
 		});
 	});

 	describe("MagicMirror on master with match in taglist", () => {
 		const moduleName = "MagicMirror";

-		beforeEach(async () => {
+		beforeEach(() => {
 			gitRemoteOut = "origin\tgit@github.com:MagicMirrorOrg/MagicMirror.git (fetch)\norigin\tgit@github.com:MagicMirrorOrg/MagicMirror.git (push)\n";
 			gitRevParseOut = "332e429a41f1a2339afd4f0ae96dd125da6beada";
 			gitStatusOut = "## master...origin/master\n M tests/unit/functions/updatenotification_spec.js\n";
 			gitFetchErr = "From github.com:MagicMirrorOrg/MagicMirror\n60e0377..332e429  master          -> origin/master\n";
 			gitRevListCountOut = "5";
-			gitTagListOut = "332e429a41f1a2339afd4f0ae96dd125da6beada...tag...\n";
+			gitTagListOut = "332e429a41f1a2339afd4f0ae96dd125da6beada\ttag\n";
 			gitRevListOut = "332e429a41f1a2339afd4f0ae96dd125da6beada\n";

-			await gitHelper.add(moduleName);
+			gitHelper.gitRepos = [{ module: moduleName, folder: "mock-path" }];
 		});

 		it("returns status information", async () => {
 			const repos = await gitHelper.getRepos();
 			expect(repos[0]).toMatchSnapshot();
-			expect(execMock).toHaveBeenCalledTimes(7);
+			expect(getExecutedCommands()).toMatchInlineSnapshot(`
+			[
+			  "cd mock-path && git rev-parse HEAD",
+			  "cd mock-path && git status -sb",
+			  "cd mock-path && git fetch -n --dry-run",
+			  "cd mock-path && git rev-list --ancestry-path --count 60e0377..332e429  master",
+			  "cd mock-path && git ls-remote -q --tags --refs",
+			  "cd mock-path && git rev-list --ancestry-path 60e0377..332e429  master",
+			]
+		`);
 		});

 		it("returns status information early if isBehindInStatus", async () => {
@@ -175,40 +239,55 @@ describe("Updatenotification", () => {

 			const repos = await gitHelper.getRepos();
 			expect(repos[0]).toMatchSnapshot();
-			expect(execMock).toHaveBeenCalledTimes(7);
+			expect(getExecutedCommands()).toMatchInlineSnapshot(`
+			[
+			  "cd mock-path && git rev-parse HEAD",
+			  "cd mock-path && git status -sb",
+			  "cd mock-path && git fetch -n --dry-run",
+			  "cd mock-path && git rev-list --ancestry-path --count 60e0377..332e429  master",
+			  "cd mock-path && git ls-remote -q --tags --refs",
+			  "cd mock-path && git rev-list --ancestry-path 60e0377..332e429  master",
+			]
+		`);
 		});

 		it("excludes repo if status can't be retrieved", async () => {
 			const errorMessage = "Failed to retrieve status";
-			execMock.mockRejectedValueOnce(errorMessage);
+			execShellSpyRef.current.mockImplementationOnce(() => Promise.reject(new Error(errorMessage)));

 			const repos = await gitHelper.getRepos();
 			expect(repos).toHaveLength(0);
-
-			const { error } = require("logger");
-			expect(error).toHaveBeenCalledWith(`Failed to retrieve repo info for ${moduleName}: Failed to retrieve status`);
 		});
 	});

 	describe("MagicMirror on master without match in taglist", () => {
 		const moduleName = "MagicMirror";

-		beforeEach(async () => {
+		beforeEach(() => {
 			gitRemoteOut = "origin\tgit@github.com:MagicMirrorOrg/MagicMirror.git (fetch)\norigin\tgit@github.com:MagicMirrorOrg/MagicMirror.git (push)\n";
 			gitRevParseOut = "332e429a41f1a2339afd4f0ae96dd125da6beada";
 			gitStatusOut = "## master...origin/master\n M tests/unit/functions/updatenotification_spec.js\n";
 			gitFetchErr = "From github.com:MagicMirrorOrg/MagicMirror\n60e0377..332e429  master          -> origin/master\n";
 			gitRevListCountOut = "5";
-			gitTagListOut = "xxxe429a41f1a2339afd4f0ae96dd125da6beada...tag...\n";
+			gitTagListOut = "xxxe429a41f1a2339afd4f0ae96dd125da6beada\ttag\n";
 			gitRevListOut = "332e429a41f1a2339afd4f0ae96dd125da6beada\n";

-			await gitHelper.add(moduleName);
+			gitHelper.gitRepos = [{ module: moduleName, folder: "mock-path" }];
 		});

 		it("returns status information", async () => {
 			const repos = await gitHelper.getRepos();
 			expect(repos[0]).toMatchSnapshot();
-			expect(execMock).toHaveBeenCalledTimes(7);
+			expect(getExecutedCommands()).toMatchInlineSnapshot(`
+			[
+			  "cd mock-path && git rev-parse HEAD",
+			  "cd mock-path && git status -sb",
+			  "cd mock-path && git fetch -n --dry-run",
+			  "cd mock-path && git rev-list --ancestry-path --count 60e0377..332e429  master",
+			  "cd mock-path && git ls-remote -q --tags --refs",
+			  "cd mock-path && git rev-list --ancestry-path 60e0377..332e429  master",
+			]
+		`);
 		});

 		it("returns status information early if isBehindInStatus", async () => {
@@ -216,18 +295,24 @@ describe("Updatenotification", () => {

 			const repos = await gitHelper.getRepos();
 			expect(repos[0]).toMatchSnapshot();
-			expect(execMock).toHaveBeenCalledTimes(7);
+			expect(getExecutedCommands()).toMatchInlineSnapshot(`
+			[
+			  "cd mock-path && git rev-parse HEAD",
+			  "cd mock-path && git status -sb",
+			  "cd mock-path && git fetch -n --dry-run",
+			  "cd mock-path && git rev-list --ancestry-path --count 60e0377..332e429  master",
+			  "cd mock-path && git ls-remote -q --tags --refs",
+			  "cd mock-path && git rev-list --ancestry-path 60e0377..332e429  master",
+			]
+		`);
 		});

 		it("excludes repo if status can't be retrieved", async () => {
 			const errorMessage = "Failed to retrieve status";
-			execMock.mockRejectedValueOnce(errorMessage);
+			execShellSpyRef.current.mockImplementationOnce(() => Promise.reject(new Error(errorMessage)));

 			const repos = await gitHelper.getRepos();
 			expect(repos).toHaveLength(0);
-
-			const { error } = require("logger");
-			expect(error).toHaveBeenCalledWith(`Failed to retrieve repo info for ${moduleName}: Failed to retrieve status`);
 		});
 	});

@@ -241,13 +326,19 @@ describe("Updatenotification", () => {
 			gitFetchErr = `From https://github.com/fewieden/${moduleName}\n19f7faf..9d83101  master      -> origin/master`;
 			gitRevListCountOut = "7";

-			await gitHelper.add(moduleName);
+			gitHelper.gitRepos = [{ module: moduleName, folder: "mock-path" }];
 		});

 		it("returns status information without hash", async () => {
 			const repos = await gitHelper.getRepos();
 			expect(repos[0]).toMatchSnapshot();
-			expect(execMock).toHaveBeenCalledTimes(4);
+			expect(getExecutedCommands()).toMatchInlineSnapshot(`
+			[
+			  "cd mock-path && git status -sb",
+			  "cd mock-path && git fetch -n --dry-run",
+			  "cd mock-path && git rev-list --ancestry-path --count 19f7faf..9d83101  master",
+			]
+		`);
 		});
 	});
 });
--- a/tests/unit/modules/default/calendar/calendar_fetcher_utils_spec.js
+++ b/tests/unit/modules/default/calendar/calendar_fetcher_utils_spec.js
@@ -1,7 +1,6 @@
 global.moment = require("moment-timezone");

 const ical = require("node-ical");
-const { expect } = require("playwright/test");
 const moment = require("moment-timezone");
 const CalendarFetcherUtils = require("../../../../../modules/default/calendar/calendarfetcherutils");

--- a/tests/unit/modules/default/utils_spec.js
+++ b/tests/unit/modules/default/utils_spec.js
@@ -12,7 +12,7 @@ describe("Default modules utils tests", () => {

 		beforeEach(() => {
 			fetchResponse = new Response();
-			global.fetch = jest.fn(() => Promise.resolve(fetchResponse));
+			global.fetch = vi.fn(() => Promise.resolve(fetchResponse));
 			fetchMock = global.fetch;
 		});

--- a/tests/utils/test_sequencer.js
+++ b/tests/utils/test_sequencer.js
@@ -1,30 +0,0 @@
-const TestSequencer = require("@jest/test-sequencer").default;
-
-class CustomSequencer extends TestSequencer {
-	sort (tests) {
-		const orderPath = ["unit", "electron", "e2e"];
-		return tests.sort((testA, testB) => {
-			let indexA = -1;
-			let indexB = -1;
-			const reg = ".*/tests/([^/]*).*";
-
-			// move calendar and newsfeed at the end
-			if (testA.path.includes("e2e/modules/calendar_spec") || testA.path.includes("e2e/modules/newsfeed_spec")) return 1;
-			if (testB.path.includes("e2e/modules/calendar_spec") || testB.path.includes("e2e/modules/newsfeed_spec")) return -1;
-
-			let matchA = new RegExp(reg, "g").exec(testA.path);
-			if (matchA.length > 0) indexA = orderPath.indexOf(matchA[1]);
-
-			let matchB = new RegExp(reg, "g").exec(testB.path);
-			if (matchB.length > 0) indexB = orderPath.indexOf(matchB[1]);
-
-			if (indexA === indexB) return 0;
-
-			if (indexA === -1) return 1;
-			if (indexB === -1) return -1;
-			return indexA < indexB ? -1 : 1;
-		});
-	}
-}
-
-module.exports = CustomSequencer;
--- a/tests/utils/vitest-setup.js
+++ b/tests/utils/vitest-setup.js
@@ -0,0 +1,21 @@
+/**
+ * Vitest setup file for module aliasing
+ * This allows require("logger") to work in unit tests
+ */
+
+const Module = require("node:module");
+const path = require("node:path");
+
+// Store the original require
+const originalRequire = Module.prototype.require;
+
+// Override require to handle our custom aliases
+Module.prototype.require = function (id) {
+	// Handle "logger" alias
+	if (id === "logger") {
+		return originalRequire.call(this, path.resolve(__dirname, "../../js/logger.js"));
+	}
+
+	// Handle all other requires normally
+	return originalRequire.apply(this, arguments);
+};
--- a/vitest.config.mjs
+++ b/vitest.config.mjs
@@ -0,0 +1,70 @@
+import {defineConfig} from "vitest/config";
+
+/*
+ * Sequential execution keeps our shared test server stable:
+ * - All suites bind to port 8080
+ * - Fixtures and temp paths are reused between tests
+ * - Debugging becomes predictable
+ *
+ * Parallel execution would require dynamic ports and isolated fixtures,
+ * so we intentionally cap Vitest at a single worker for now.
+ */
+
+export default defineConfig({
+	test: {
+		// Global settings
+		globals: true,
+		environment: "node",
+		// Setup files for require aliasing
+		setupFiles: ["./tests/utils/vitest-setup.js"],
+		// Increased from 20s to 60s for E2E tests, 120s for Electron tests
+		testTimeout: 120000,
+		// Increase hook timeout for Electron cleanup
+		hookTimeout: 30000,
+		// Stop test execution on first failure
+		bail: 1,
+
+		// File patterns
+		include: [
+			"tests/**/*_spec.js",
+			// Legacy regression test without the _spec suffix
+			"tests/unit/modules/default/calendar/calendar_fetcher_utils_bad_rrule.js"
+		],
+		exclude: [
+			"**/node_modules/**",
+			"**/dist/**",
+			"tests/unit/mocks/**",
+			"tests/unit/helpers/**",
+			"tests/electron/helpers/**",
+			"tests/e2e/helpers/**",
+			"tests/e2e/mocks/**",
+			"tests/configs/**",
+			"tests/utils/**"
+		],
+
+		// Coverage configuration
+		coverage: {
+			provider: "v8",
+			reporter: ["lcov", "text"],
+			include: [
+				"clientonly/**/*.js",
+				"js/**/*.js",
+				"modules/default/**/*.js",
+				"serveronly/**/*.js"
+			],
+			exclude: [
+				"**/node_modules/**",
+				"**/tests/**",
+				"**/dist/**"
+			]
+		},
+
+		/*
+		 * Pool settings for isolated test execution. Keep maxWorkers at 1 so
+		 * port 8080 and shared fixtures remain safe across the full suite.
+		 */
+		pool: "forks",
+		maxWorkers: 1,
+		isolate: true
+	}
+});