fix: resolve CodeQL alerts #24 and #26 (#4145)

**[#24](https://github.com/MagicMirrorOrg/MagicMirror/security/code-scanning/24)
– `js/class.js`**

`fnTest` works by serialising a function to a string and checking if
`"xyz"` appears in it - the function is never actually called. The bare
`xyz;` is never executed, so CodeQL is right to flag it. `return xyz;`
makes the intent clear. So this is purely a cosmetic change.


**[#26](https://github.com/MagicMirrorOrg/MagicMirror/security/code-scanning/26)
– `tests/e2e/helpers/global-setup.js`**

CodeQL flagged `if (exec) exec;` as a useless expression - and it was
right. But the real find was one level deeper.

`startApplication` hardcoded `const port = 8080`, so `MM_PORT` was
always overwritten before the app started. The test named "Set port 8100
on environment variable MM_PORT" was actually testing port 8080 the
whole time - it just happened to pass anyway.

Removed the dead `exec` parameter, made `startApplication` read
`MM_PORT` from the environment, and fixed the test so it actually checks
what it says it checks.

Author: KristjanESPERANTO

js/class.js

@@ -11,7 +11,7 @@
 (function () {
 	let initializing = false;
 	const fnTest = (/xyz/).test(function () {
-		xyz;
+		return xyz;
 	})
 		? /\b_super\b/
 		: /.*/;

tests/e2e/helpers/global-setup.js

@@ -88,7 +88,7 @@ exports.getPage = () => {
 	return page;
 };
 
-exports.startApplication = async (configFilename, exec) => {
+exports.startApplication = async (configFilename) => {
 	vi.resetModules();
 
 	// Clear Node's require cache for config and app files to prevent stale configs and middlewares
@@ -107,8 +107,8 @@ exports.startApplication = async (configFilename, exec) => {
 		await exports.stopApplication();
 	}
 
-	// Use fixed port 8080 (tests run sequentially, no conflicts)
-	const port = 8080;
+	// Use MM_PORT if preset by a test, otherwise default to 8080.
+	const port = Number(process.env.MM_PORT) || 8080;
 	global.testPort = port;
 
 	// Set config sample for use in test
@@ -121,12 +121,11 @@ exports.startApplication = async (configFilename, exec) => {
 
 	process.env.MM_CONFIG_FILE = configPath;
 
-	// Override port in config - MUST be set before app loads
+	// Ensure MM_PORT is set before app loads
 	process.env.MM_PORT = port.toString();
 
 	process.env.mmTestMode = "true";
 	process.setMaxListeners(0);
-	if (exec) exec;
 	global.app = require(`${global.root_path}/js/app`);
 
 	return global.app.start();
@@ -143,6 +142,7 @@ exports.stopApplication = async (waitTime = 100) => {
 	await global.app.stop();
 	delete global.app;
 	delete global.testPort;
+	delete process.env.MM_PORT;
 
 	// Wait for any pending async operations to complete before closing DOM
 	await new Promise((resolve) => setTimeout(resolve, waitTime));

tests/e2e/port_spec.js

@@ -11,24 +11,24 @@ describe("port directive configuration", () => {
 		});
 
 		it("should return 200", async () => {
-			const port = global.testPort || 8080;
-			const res = await fetch(`http://localhost:${port}`);
+			const res = await fetch(`http://localhost:${global.testPort}`);
 			expect(res.status).toBe(200);
 		});
 	});
 
 	describe("Set port 8100 on environment variable MM_PORT", () => {
 		beforeAll(async () => {
-			await helpers.startApplication("tests/configs/port_8090.js", (process.env.MM_PORT = 8100));
+			process.env.MM_PORT = "8100";
+			await helpers.startApplication("tests/configs/port_8090.js");
 		});
 
 		afterAll(async () => {
 			await helpers.stopApplication();
 		});
 
 		it("should return 200", async () => {
-			const port = global.testPort || 8080;
-			const res = await fetch(`http://localhost:${port}`);
+			expect(global.testPort).toBe(8100);
+			const res = await fetch(`http://localhost:${global.testPort}`);
 			expect(res.status).toBe(200);
 		});
 	});