refactor(tests): use submodule instead

src/mkHome.nix

@@ -4,9 +4,14 @@
 # SPDX-License-Identifier: MIT
 
 { lib }:
-userSet: shell: suites:
+{
+  homeModule ? [ ],
+  user,
+  shell,
+  suites ? [ ],
+}:
 let
-  user = lib.head (lib.attrNames userSet);
+  userName = lib.head (lib.attrNames user);
   pathsToLinkShell = lib.elem shell [
     "fish"
     "zsh"
@@ -17,8 +22,9 @@ let
 in
 {
   imports =
-    [
-      { users.users = userSet; }
+    lib.flatten [
+      homeModule
+      { users.users = user; }
       (
         { pkgs, lib, ... }:
         {
@@ -29,17 +35,18 @@ in
                 home-manager.useGlobalPkgs = lib.mkDefault true;
                 home-manager.useUserPackages = lib.mkDefault true;
 
-                home-manager.users.${user} = {
+                home-manager.users.${userName} = {
                   imports = lib.flatten [
                     suites
                     { programs.${shell}.enable = true; }
                   ];
                   home.stateVersion =
                     if pkgs.stdenv.isDarwin then pkgs.lib.trivial.release else "24.05";
                 };
-                users.users.${user} = {
+                users.users.${userName} = {
                   shell = pkgs."${shell}";
-                  home = if pkgs.stdenv.isDarwin then "/Users/${user}" else "/home/${user}";
+                  home =
+                    if pkgs.stdenv.isDarwin then "/Users/${userName}" else "/home/${userName}";
                 };
               }
               enableDefaultShellProgram

src/pops/homeProfiles.nix

@@ -9,12 +9,28 @@
   POP,
   flops,
   haumea,
+  lib,
 }:
 (super.homeModules.addLoadExtender {
   load = {
     src = projectRoot + "/units/nixos/homeProfiles";
     type = "nixosProfilesOmnibus";
     transformer = [ (_: _: _) ];
+    inputsTransformer = [
+      (
+        self:
+        self
+        // (
+          let
+            system = if self ? system then self.system else throw "system is required";
+          in
+          {
+            isDarwin = lib.elem system lib.systems.doubles.darwin;
+            isLinux = lib.elem system lib.systems.doubles.linux;
+          }
+        )
+      )
+    ];
   };
 }).addExporters
   [

src/pops/nixosProfiles.nix

@@ -8,12 +8,28 @@
   projectRoot,
   POP,
   flops,
+  lib,
 }:
 (super.nixosModules.addLoadExtender {
   load = {
     src = projectRoot + "/units/nixos/nixosProfiles";
     type = "nixosProfilesOmnibus";
     transformer = [ (_: _: _) ];
+    inputsTransformer = [
+      (
+        self:
+        self
+        // (
+          let
+            system = if self ? system then self.system else throw "system is required";
+          in
+          {
+            isDarwin = lib.elem system lib.systems.doubles.darwin;
+            isLinux = lib.elem system lib.systems.doubles.linux;
+          }
+        )
+      )
+    ];
   };
 }).addExporters
   [