xdg.userDirs: add test cases

Make the existing test case non-Linux-specific, and add a couple of
others for the new functionality.

Author: sellout

tests/modules/misc/xdg/default.nix

@@ -4,4 +4,7 @@
   xdg-mime-disabled = ./mime-disabled.nix;
   xdg-autostart = ./autostart.nix;
   xdg-autostart-readonly = ./autostart-readonly.nix;
+  xdg-user-dirs-mixed = ./user-dirs-mixed.nix;
+  xdg-user-dirs-null = ./user-dirs-null.nix;
+  xdg-user-dirs-short = ./user-dirs-short.nix;
 }

tests/modules/misc/xdg/linux.nix

@@ -2,7 +2,6 @@
   xdg-mime-apps-basics = ./mime-apps-basics.nix;
   xdg-system-dirs = ./system-dirs.nix;
   xdg-desktop-entries = ./desktop-entries.nix;
-  xdg-user-dirs-null = ./user-dirs-null.nix;
   xdg-portal = ./portal.nix;
   xdg-mime = ./mime.nix;
   xdg-mime-package = ./mime-packages.nix;

tests/modules/misc/xdg/user-dirs-mixed.nix

@@ -0,0 +1,35 @@
+{
+  config,
+  pkgs,
+  ...
+}:
+
+{
+  config = {
+    home.stateVersion = "25.05";
+
+    xdg.userDirs = {
+      enable = true;
+      extraConfig.PROJECTS = "${config.home.homeDirectory}/Projects";
+      ## This will stop working with stateVersion 25.11.
+      extraConfig.XDG_MISC_DIR = "${config.home.homeDirectory}/Misc";
+    };
+
+    nmt.script = ''
+      configFile=home-files/.config/user-dirs.dirs
+      assertFileExists $configFile
+      assertFileContent $configFile ${pkgs.writeText "expected" ''
+        XDG_DESKTOP_DIR="/home/hm-user/Desktop"
+        XDG_DOCUMENTS_DIR="/home/hm-user/Documents"
+        XDG_DOWNLOAD_DIR="/home/hm-user/Downloads"
+        XDG_MISC_DIR="/home/hm-user/Misc"
+        XDG_MUSIC_DIR="/home/hm-user/Music"
+        XDG_PICTURES_DIR="/home/hm-user/Pictures"
+        XDG_PROJECTS_DIR="/home/hm-user/Projects"
+        XDG_PUBLICSHARE_DIR="/home/hm-user/Public"
+        XDG_TEMPLATES_DIR="/home/hm-user/Templates"
+        XDG_VIDEOS_DIR="/home/hm-user/Videos"
+      ''}
+    '';
+  };
+}

tests/modules/misc/xdg/user-dirs-short.nix

@@ -0,0 +1,30 @@
+{
+  config,
+  pkgs,
+  ...
+}:
+
+{
+  config = {
+    xdg.userDirs = {
+      enable = true;
+      extraConfig.PROJECTS = "${config.home.homeDirectory}/Projects";
+    };
+
+    nmt.script = ''
+      configFile=home-files/.config/user-dirs.dirs
+      assertFileExists $configFile
+      assertFileContent $configFile ${pkgs.writeText "expected" ''
+        XDG_DESKTOP_DIR="/home/hm-user/Desktop"
+        XDG_DOCUMENTS_DIR="/home/hm-user/Documents"
+        XDG_DOWNLOAD_DIR="/home/hm-user/Downloads"
+        XDG_MUSIC_DIR="/home/hm-user/Music"
+        XDG_PICTURES_DIR="/home/hm-user/Pictures"
+        XDG_PROJECTS_DIR="/home/hm-user/Projects"
+        XDG_PUBLICSHARE_DIR="/home/hm-user/Public"
+        XDG_TEMPLATES_DIR="/home/hm-user/Templates"
+        XDG_VIDEOS_DIR="/home/hm-user/Videos"
+      ''}
+    '';
+  };
+}