Function isPanel

src/background/utils/tab.ts:6–8

(sender: chrome.runtime.MessageSender)

// On Vivaldi, sometimes sender.tab is undefined as well, but error is not very helpful.
// On Opera, sender.tab.index === -1.
export function isPanel(sender: chrome.runtime.MessageSender): boolean {
    return typeof sender === 'undefined' || typeof sender.tab === 'undefined' || (isOpera && sender.tab.index === -1);
}