Can I share code between different parts of Chrome Extension?

Question

Let\'s say, I have a function:

var rand = function(n) {
    return Math.floor(Math.random() * n);
}

Can I use this function in both Content Scr

Answer 1

Yes, you can, by putting it in a separate JS file and loading it in both.

Say, you have a file utils.js that contain all such functions.

Then you can load the background page like this:

"background": {
  "scripts": [ "utils.js", "background.js" ]
},

And the content script like this:

"content_scripts": [
  {
    "matches": ["..."],
    "js": ["utils.js", "content.js"]
  }
],

Or, if you're using programmatic injection, chain the calls like this:

chrome.tabs.executeScript(tabId, {file: "utils.js"}, function(){
  chrome.tabs.executeScript(tabId, {file: "content.js"}, yourActualCallback);
});