// Returns a promise of the tab object
(function createTab [:String url]
    (API.browser.tabs.create (objectWith url)))

(function sendMessage [:Int tabId :String type :Array<Dynamic> data]
    (API.browser.tabs.sendMessage tabId (objectWith type data)))

// Requires the activeTab permission in manifest.json
(function runCode [tab :String jsCode]
    (API.browser.tabs.executeScript tab.id
        (object code jsCode)))