refactor(home): share XDG base configuration

home/base/core/xdg.nix

@@ -0,0 +1,10 @@
+{ config, ... }:
+{
+  xdg = {
+    enable = true;
+    cacheHome = "${config.home.homeDirectory}/.cache";
+    configHome = "${config.home.homeDirectory}/.config";
+    dataHome = "${config.home.homeDirectory}/.local/share";
+    stateHome = "${config.home.homeDirectory}/.local/state";
+  };
+}

home/darwin/default.nix

@@ -17,7 +17,4 @@
     ../base/gui
     ../base/home.nix
   ];
-
-  # enable management of XDG base directories on macOS.
-  xdg.enable = true;
 }

home/linux/gui/base/xdg/default.nix

@@ -16,21 +16,12 @@
     xdg-user-dirs
   ];
 
-  xdg = {
+  xdg.userDirs = {
     enable = true;
-
-    cacheHome = "${config.home.homeDirectory}/.cache";
-    configHome = "${config.home.homeDirectory}/.config";
-    dataHome = "${config.home.homeDirectory}/.local/share";
-    stateHome = "${config.home.homeDirectory}/.local/state";
-
-    userDirs = {
-      enable = true;
-      setSessionVariables = true;
-      createDirectories = true;
-      extraConfig = {
-        SCREENSHOTS = "${config.xdg.userDirs.pictures}/Screenshots";
-      };
+    setSessionVariables = true;
+    createDirectories = true;
+    extraConfig = {
+      SCREENSHOTS = "${config.xdg.userDirs.pictures}/Screenshots";
     };
   };
 }

outputs/x86_64-linux/tests/home-manager-xdg/expected.nix

@@ -0,0 +1,14 @@
+{ myvars, lib }:
+let
+  username = myvars.username;
+in
+lib.genAttrs
+  [
+    "ai-niri"
+    "aquamarine"
+    "ruby"
+  ]
+  (_: {
+    enable = true;
+    stateHome = "/home/${username}/.local/state";
+  })

outputs/x86_64-linux/tests/home-manager-xdg/expr.nix

@@ -0,0 +1,19 @@
+{
+  myvars,
+  lib,
+  outputs,
+}:
+let
+  username = myvars.username;
+  hosts = [
+    "ai-niri"
+    "aquamarine"
+    "ruby"
+  ];
+in
+lib.genAttrs hosts (name: {
+  inherit (outputs.nixosConfigurations.${name}.config.home-manager.users.${username}.xdg)
+    enable
+    stateHome
+    ;
+})