CrunchyDL/src/electron/singleInstance.ts

import { App, BrowserWindow } from 'electron'

export default (app: App, win: BrowserWindow) => {
    const gotTheLock = app.requestSingleInstanceLock()

    if (!gotTheLock) {
        app.quit()
        return true
    }

    app.on('second-instance', (_, _argv) => {
        if (win) {
            win.show()
            if (win.isMinimized()) win.restore()
            win.focus()
        }
    })

    app.on('open-url', function (event, url) {
        event.preventDefault()
        win.webContents.send('deeplink', url)
    })
}