sway: add preCheckConfig to customize check environment

[amarshall]

Description

See commit messages.

Checklist

• Change is backwards compatible.

• Code formatted with ./format.

• Code tested through nix-shell --pure tests -A run.all or nix develop --ignore-environment .#all using Flakes.

• Test cases updated/added. See example.

• Commit messages are formatted like

  {component}: {description}
  
  {long description}
  

  See CONTRIBUTING for more information and recent commit messages for examples.

• If this PR adds a new module

  • Added myself as module maintainer. See example.

Maintainer CC

[teto]

not worth the complexity IMO. Either users make it work in hte sandbox or they disable the check. One thing we could do if there are too many complaints is to toggle the check off by default

[amarshall]

Where exactly is the complexity? It’s one new option and two lines of code to use it (plus tests).

FWIW, there’s precedence for this sort of thing in NixOS modules (e.g. bird and nftables, which I based this off knowing those exist). Tbh, it doesn’t really matter too much to me as I personally do not need this, and if I did, I would just patch it as I did the actual check for a year.

One argument is that, unlike pkgs, it’s not possible to use overlays for modules, which causes frustration for folks when they want extensibility (so the only way to extend is to patch, which can be cumbersome for some).

[teto]

Where exactly is the complexity? It’s one new option and two lines of code to use it (plus tests).

the diff is 40 lines to modify the check such that it doesn't check the final config, turning it into a potentially useless check. If you dont use it I dont see why we should carry the burden upstream.

One argument is that, unlike pkgs, it’s not possible to use overlays for modules, which causes frustration for folks when they want extensibility (so the only way to extend is to patch, which can be cumbersome for some).

You can perfectly add options under the same namespace via imports. You can see here https://github.com/teto/home/blob/main/hm/modules/zsh.nix how I extend the zsh module for instance.

[amarshall]

I added it to try to solve a problem people had in the linked issue. The alternative to “potentially useless” is, as noted in the commit msg, totally useless as it had to be disabled.

That works if the extension is additive, but I don’t see how it works if the “extension” needs to modify an existing thing without completely overwriting it. If you have an example of that, I’d certainly be interested to see it as I repeatedly face such a problem in both HM and NixOS config.