sidebarAction.getTitle()

details

object. An object with the following properties:

tabId Optional

integer. Get the title for the sidebar specific to the given tab.

windowId Optional

integer. Get the title for the sidebar specific to the given window.

• If windowId and tabId are both supplied, the function fails and the promise it returns is rejected.
• If windowId and tabId are both omitted, the global title is returned.

A Promise that will be fulfilled with a string containing the sidebar's title.

This code switches the title between "this" and "that" each time the user clicks the browser action

function toggleTitle(title) {
  if (title == "this") {
    browser.sidebarAction.setTitle({title: "that"});
  } else {
    browser.sidebarAction.setTitle({title: "this"});
  }
}

browser.browserAction.onClicked.addListener(() => {
  let gettingTitle = browser.sidebarAction.getTitle({});
  gettingTitle.then(toggleTitle);
});