Add single instance lock

src/main/index.ts

@@ -7,36 +7,51 @@ import { join } from "path";
 import { DATA_DIR, VENCORD_FILES_DIR } from "./constants";
 
 import { once } from "../shared/utils/once";
-import "./ipc";
 import { ensureVencordFiles } from "./utils/vencordLoader";
 
+import "./ipc";
+
 // Make the Vencord files use our DATA_DIR
 process.env.VENCORD_USER_DATA_DIR = DATA_DIR;
 
 const runVencordMain = once(() => require(join(VENCORD_FILES_DIR, "main.js")));
 
+let mainWin: BrowserWindow | null = null;
+
+if (!app.requestSingleInstanceLock()) {
+    console.log("Vencord Desktop is already running. Quitting...");
+    app.quit();
+} else {
+    app.on("second-instance", () => {
+        if (mainWin) {
+            if (mainWin.isMinimized()) mainWin.restore();
+            mainWin.focus();
+        }
+    });
+
+    app.whenReady().then(async () => {
+        createWindows();
+
+        app.on('activate', () => {
+            if (BrowserWindow.getAllWindows().length === 0) createWindows();
+        });
+    });
+}
+
 async function createWindows() {
     const splash = createSplashWindow();
 
     await ensureVencordFiles();
     runVencordMain();
 
-    const mainWindow = createMainWindow();
+    mainWin = createMainWindow();
 
-    mainWindow.once("ready-to-show", () => {
+    mainWin.once("ready-to-show", () => {
         splash.destroy();
-        mainWindow.show();
+        mainWin!.show();
     });
 }
 
-app.whenReady().then(async () => {
-    createWindows();
-
-    app.on('activate', () => {
-        if (BrowserWindow.getAllWindows().length === 0) createWindows();
-    });
-});
-
 app.on("window-all-closed", () => {
     if (process.platform !== "darwin")
         app.quit();