feat: user-packages and system-packages batteries

modules/aspects/batteries/pkgs.nix

@@ -0,0 +1,79 @@
+{ den, ... }:
+let
+  description = ''
+    Includes a package at User and Home levels.
+
+    Works in NixOS/Darwin and standalone Home-Manager
+
+    ## Usage
+
+       # for NixOS/Darwin
+       den.aspects.my-user.includes = [ (den._.user-packages [ "hello" ]) ]
+
+       # for standalone home-manager
+       den.aspects.my-home.includes = [ den._.user-packages [ "hello" ]) ]
+
+    or globally (automatically applied depending on context):
+
+       den.default.includes = [ den._.user-packages [ "hello" ]) ]
+  '';
+
+  hostPackages =
+    getPkgs:
+    let
+      nixos = { pkgs, ... }: {
+        environment.systemPackages = getPkgs pkgs;
+      };
+      darwin = nixos;
+    in
+    {
+      inherit nixos darwin;
+    };
+
+  userPackages =
+    getPkgs:
+    let
+      nixos = { user, pkgs, ... }: {
+        users.users.${user.name}.packages = getPkgs pkgs;
+      };
+      darwin = nixos;
+    in
+    {
+      inherit nixos darwin;
+    };
+
+  homePackages =
+    getPkgs:
+    let
+      homeManager = { pkgs, ... }: {
+        home.packages = getPkgs pkgs;
+      };
+    in
+    {
+      inherit homeManager;
+    };
+
+  to-host = getPkgs: { host, ... }: hostPackages getPkgs;
+  to-host-only = getPkgs: { host }: hostPackages getPkgs;
+  to-user = userPackages;
+  to-home = homePackages;
+
+  __functor = _self: getPkgs: {
+      includes = [
+        (to-host-only getPkgs)
+        (to-user getPkgs)
+        (to-home getPkgs)
+      ];
+    };
+
+in
+{
+  den.batteries.pkgs = {
+    inherit
+      description
+      __functor
+      to-host
+      to-user
+      to-home;
+  };
+}

templates/ci/modules/features/pkgs.nix

@@ -0,0 +1,97 @@
+{ denTest, ... }:
+{
+  flake.tests.pkgs = {
+
+    test-pkgs-set-on-host = denTest (
+      { den, igloo, ... }:
+      {
+        den.hosts.x86_64-linux.igloo.users.tux = { };
+        den.aspects.igloo.includes = [ (den.batteries.pkgs (pkgs: [pkgs.hello])) ];
+
+        expr = builtins.elem "hello" (builtins.map (pkg: (builtins.head (builtins.splitVersion pkg.name))) igloo.environment.systemPackages);
+        expected = true;
+      }
+    );
+
+    test-pkgs-set-on-user = denTest (
+      { den, igloo, ... }:
+      {
+        den.hosts.x86_64-linux.igloo.users.tux = { };
+        den.aspects.tux.includes = [ (den.batteries.pkgs (pkgs: [pkgs.hello])) ];
+
+        expr = builtins.elem "hello" (builtins.map (pkg: pkg.pname) igloo.users.users.tux.packages);
+        expected = true;
+      }
+    );
+
+    test-pkgs-set-on-home-manager = denTest (
+      { den, tuxHm, ... }:
+      {
+        den.hosts.x86_64-linux.igloo.users.tux.classes = [ "homeManager" ];
+        den.default.homeManager.home.stateVersion = "25.11";
+        den.aspects.tux.includes = [ (den.batteries.pkgs (pkgs: [pkgs.hello])) ];
+
+        expr = builtins.elem "hello" (builtins.map (pkg: (builtins.head (builtins.splitVersion pkg.name))) tuxHm.home.packages);
+        expected = true;
+      }
+    );
+
+    test-pkgs-to-host-set-on-host = denTest (
+      { den, igloo, ... }:
+      {
+        den.hosts.x86_64-linux.igloo.users.tux = { };
+        den.aspects.tux.includes = [ (den.batteries.pkgs.to-host (pkgs: [pkgs.hello])) ];
+
+        expr = builtins.elem "hello" (builtins.map (pkg: (builtins.head (builtins.splitVersion pkg.name))) igloo.environment.systemPackages);
+        expected = true;
+      }
+    );
+
+    test-pkgs-to-user-set-on-user = denTest (
+      { den, igloo, ... }:
+      {
+        den.hosts.x86_64-linux.igloo.users.tux = { };
+        den.aspects.tux.includes = [ (den.batteries.pkgs.to-user (pkgs: [pkgs.hello])) ];
+
+        expr = builtins.elem "hello" (builtins.map (pkg: pkg.pname) igloo.users.users.tux.packages);
+        expected = true;
+      }
+    );
+
+    test-pkgs-to-home-set-on-home-manager = denTest (
+      { den, tuxHm, ... }:
+      {
+        den.hosts.x86_64-linux.igloo.users.tux.classes = [ "homeManager" ];
+        den.default.homeManager.home.stateVersion = "25.11";
+        den.aspects.tux.includes = [ (den.batteries.pkgs.to-home (pkgs: [pkgs.hello])) ];
+
+        expr = builtins.elem "hello" (builtins.map (pkg: (builtins.head (builtins.splitVersion pkg.name))) tuxHm.home.packages);
+        expected = true;
+      }
+    );
+
+    test-pkgs-set-on-user-not-on-host = denTest (
+      { den, igloo, ... }:
+      {
+        den.hosts.x86_64-linux.igloo.users.tux = { };
+        den.aspects.tux.includes = [ (den.batteries.pkgs (pkgs: [pkgs.hello])) ];
+
+        expr = builtins.elem "hello" (builtins.map (pkg: (builtins.head (builtins.splitVersion pkg.name))) igloo.environment.systemPackages);
+        expected = false;
+      }
+    );
+
+    test-pkgs-set-on-home-manager-not-on-user = denTest (
+      { den, igloo, ... }:
+      {
+        den.hosts.x86_64-linux.igloo.users.tux.classes = [ "homeManager" ];
+        den.default.homeManager.home.stateVersion = "25.11";
+        den.aspects.tux.includes = [ (den.batteries.pkgs (pkgs: [pkgs.hello])) ];
+
+        expr = builtins.elem "hello" (builtins.map (pkg: pkg.pname) igloo.users.users.tux.packages);
+        expected = false;
+      }
+    );
+
+  };
+}