Chrome Extension OnBeforeRequest not triggering unless I click the poupup button

Question

I'm building a chrome extension which needs to redirect a script of a certain page. My background.js includes:

    chrome.webRequest.onBeforeRequest.addListener(
        function(details) {
            if (/js\example.js/.test(details.url))
                // setTimeout(requestScript(details), 0);
                return { 
                    redirectUrl: chrome.extension.getURL("novoScript.js")
                }
        },
        {urls: ['*://*.example.com/*.js']},
        ["blocking"]
    );

The manifest.json includes:

"background": {
    "scripts": ["background.js"],
    "persistent": true
},

It works as expected, but the function only runs when I reload the page after having clicked the popup button. The first time I open the page in a new tab, it doesn't run. If I am in the page, and have clicked the popup button, it always works. If I haven't clicked, it doesn't matter how many times I reload, the redirect doesn't work.

I've tried erasing the whole content of popup.js, and it doesn't make a difference, so it's not because of any code there.

Also, I've checkedthe background.js file is not being ran again, so it seems that the listener is there, but it doesn't listen if I don't click the popup button. I've also added console.log to the listener function, and before I click the button it only logs calls to 'aobut:blank' url.

I'd like to allow the listener to work without clicking the popup, to avoid inconsistencies. Any help is appreciated.

Answer 1

I'm not sure about what was causing the problem. But an alternative approach that seems to be better overall, was pointed by @wOxxOm: declarativeNetRequest. With it, I applied a general rule for whenever the desired resource is requested.

Implementation:

manifest.json:

{
    ...    
    "declarative_net_request" : {
            "rule_resources" : [{
              "id": "ruleset_1",
              "enabled": true,
              "path": "redirectRules.json"
            }]
          },
     "permissions": [
          "declarativeNetRequest",
            "*://*.example.com/*"
        ],
      ...
}

redirectRules.json:

[{
    "id": 1,
    "priority": 1,
    "action": {"type": "redirect", "redirect": {"extensionPath": "/novoScript.js" }},
    "condition" : {
        "urlFilter" : "js/app.*.js",
        "domains": ["example.com"],
        "resourceTypes" : ["script"]
    }
}]