**First, apologies for a second PR on the same issue but I was working on this already so I thought I'd push it and let you decide which you want to merge.**
The PR is related to [13466](https://github.com/vercel/next.js/issues/13466).
Based on my research, the error happens if the options are empty, null, or undefined. That's why I have decided that the most proper check would be using the! post-fix expression operator may assert that its operand is non-null and non-undefined. ``if (options == null)``
(Optional)
I have also added a warning, which warns the user if the passed "dev" variable is not a boolean.
It's my first PR on the "packages" part of the repo so I'd be glad to receive all kinds of critics. If you want me to change or remove anything, I'm open to suggestions.
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Fixes#13466
Was going through _document and noticed some variable shadowing going on. Added a rule for it to our eslint configuration and went through all warnings with @Timer.
