Your example shows that num is never reassigned.
Which is aligned exactly with the error message you've included.

I think maybe you're misunderstanding the lint rule and how const works?

The rule isn't saying "num must be assigned to a different variable".
The rule is saying "a different value is never assigned to num".

Example:

// VALID - num is never reassigned
const num = 1;
const foo = num;

// VALID - num is reassigned
let num = 1;
num = 2;

// Invalid - num. Is never reassigned
let num = 1;
let foo = num;

@bradzacher The error I mentioned in the Actual Result was the error from the minimal repro code. The error on my use case is 'xp' is never reassigned. Use 'const' instead.

Anyways, I edited the description of the issue to maybe make it more clear

Why are you assigning to xp! instead of just xp?

Why are you assigning to xp! instead of just xp?

xp is type number | undefined because of the optional chain.
If I don't use the non-nullish assertion operator this error appears:

okay... so your example again is incorrect.

Your example should actually be

let xp: number | undefined = 1;
xp! += 1;

If you ensure your initial example and error message are together a completely isolated reproduction of your problem, then we can save all this back-and-forth next time. That's the entire point of the template.

Alright, sorry for the trouble. 😅