lib/attrsets: remove copies of recurseIntoAttrs, add recurseIntoAttrsIf

[lucasew]

I actually wanted a way to enable nixpkgs-review to at least find which tests changed the derivation path but it seems it needs a little of preparation. The idea is to pass a type of parameter to nixpkgs and then it would eval tests recursively.

I am not dealing with NixOS tests mapping yet, only a low hanging fruit I found while looking for a way to do it.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 25.05 Release Notes (or backporting 24.11 and 25.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

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[infinisil]

I don't get the motivation behind this change, can you explain it more?

[lucasew]

I don't get the motivation behind this change, can you explain it more?

I want to parametrize whether some kind of builder would recurse into a attrset based on a condition and found this low hanging fruit while I was looking for a way to do it.

[lucasew]

BTW the review bot is running now a test that will result in less messages sent.

Basically a map reduce that waits the workers to be done then send all their report.mds in one message.

Currently is just a cat reports/**/*.md > report.md but let's see how it goes.

[nixos-discourse]

This pull request has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/prs-ready-for-review/3032/4995

[roberth]

I would expect this to behave as

rec {
/** Apply a function if the condition holds; return argument unmodified otherwise. */
applyIf = cond: f: if cond then f else (x: x);
recurseIntoAttrsIf = cond: applyIf cond recurseIntoAttrs;
}

With applyIf, we don't need any of the other *If helpers.
I don't think we have this yet?
I've used the name when for it in some Nix, Elm or Haskell code, but something more explicit is probably better.