Wrong visual selection when evil motion `vi"` within quotes and templating strings with `${...}` is used

[zzantares]

I have a file like:

{ profile, pkgs, lib, ... }:

{
  programs.librewolf = {
    languagePacks = [ "en-US" ];

    profiles."${profile.login}" = {
      id = 0;
      settings = {
        "browser.search.defaultenginename" = "DuckDuckGo";
      };
    };
  };
}

when my cursor/point is within "...." for example in this line (see | showing cursor position):

...
        "brow|ser.search.defaultenginename" = "DuckDuckGo";
...

and then I do vi" to select everything within quotes (which calls evil-visual-char under the hood), I get the whole attribute set under profiles selected:

My expectation is that it should only highlight what's within quotes, i. e. browser.search.defaultenginename.

I think this has something to do with the presence of profiles."${profile.login}" = part, because if I don't do any templating there, then vi" works as expected.

I'm reporting this issue here because so far nix-mode is the only mode where I'm able to see this issue, I'm happy to help debug/fix but I just don't know where to start to look, any help is very much appreciated!

emacs-version:

GNU Emacs 29.4 (build 1, x86_64-pc-linux-gnu, X toolkit, cairo version 1.18.2, Xaw3d scroll bars)

doom-version:

Doom core     v3.0.0-pre       grafted, HEAD -> master, origin/master, origin/HEAD b55d988 2025-02-21 18:35:36 -0500
Doom modules  v25.03.0-pre     grafted, HEAD -> master, origin/master, origin/HEAD b55d988 2025-02-21 18:35:36 -0500

evil-version:

Evil version 1.15.0

[knazarov]

If you look closely, you'll see that the second (closing) quote is not colored green. Evil mode operates on syntax objects and it looks like the issue is in the syntax rules in this module.

[knazarov]

This issue in evil-mode may be relevant: emacs-evil/evil#1190

Quote:

This is related to the fact that evil uses Emacs's built-in syntax parsing facilities (parse-partial-sexp, up-list, ...) to find the bounds of strings and parenthetical groups.

[knazarov]

I did some debugging, and narrowed it down to evil-forward-quote. If you have a string (with cursor represented as _:

"foo_ ${bar} qux"

And then evaluate (evil-forward-quote ?\" 1), the cursor should move to:

"foo ${bar} qux"_

However, in reality it moves to:

"foo $_{bar} qux"

Which means that something about how syntax rules (maybe font-lock?) are set up is wrong.

Eventually, it is all from (bounds-of-evil-string-at-point) which gives incorrect values, specifically in nix-mode.