Why is this important?
What does the Hint check?
How do you resolve this issue?
For example, Lighthouse can tell you which code is dead or unused on a single page, with no context about the usage on other pages. Sitebulb actually has a 'Code Coverage' report (which you can switch on from the Advanced Settings) that can show you which files have wasted code across EVERY page of your site:
But even that comes with a warning - you don't really know that the JavaScri[t is not required:
- Sitebulb (or any tool) can't emulate user actions (such as clicking a tab) so it can't check all different combinations of page state.
- It is difficult to be sure that code is not being used for other purposes (e.g. tracking).
This means that 'just removing code because a tool told you to' is really bad advice. You could break core functionality of very important pages.
So the best advice for solving this problem is assigning it to a developer who is very familiar with the code, with the aim to improve the situation over time.