chrome-extension-cli/templates/typescript/popup/src/background.ts

The CLI for your next Chrome Extension.

'use strict';

// With background scripts you can communicate with popup
// and contentScript files.
// For more information on background script,
// See https://developer.chrome.com/extensions/background_pages

chrome.runtime.onMessage.addListener((request, sender, sendResponse) => {
  if (request.type === 'GREETINGS') {
    const message: string = `Hi ${
      sender.tab ? 'Con' : 'Pop'
    }, my name is Bac. I am from Background. It's great to hear from you.`;

    // Log message coming from the `request` parameter
    console.log(request.payload.message);
    // Send a response message
    sendResponse({
      message,
    });
  }
});