jujutsu: fix config file location on Darwin

jj looks for its config file in ~/Library/Application Support/jj on
Darwin. The previous module implementation unconditionally stored the
configuration file in $XDG_CONFIG_HOME/jj. This revision now uses the
correct location on Darwin.

modules/programs/jujutsu.nix

@@ -6,6 +6,10 @@ let
 
   cfg = config.programs.jujutsu;
   tomlFormat = pkgs.formats.toml { };
+  configDir = if pkgs.stdenv.isDarwin then
+    "Library/Application Support"
+  else
+    config.xdg.configHome;
 
 in {
   meta.maintainers = [ maintainers.shikanime ];
@@ -51,7 +55,7 @@ in {
   config = mkIf cfg.enable {
     home.packages = [ cfg.package ];
 
-    xdg.configFile."jj/config.toml" = mkIf (cfg.settings != { }) {
+    home.file."${configDir}/jj/config.toml" = mkIf (cfg.settings != { }) {
       source = tomlFormat.generate "jujutsu-config" (cfg.settings
         // optionalAttrs (cfg.ediff) (let
           emacsDiffScript = pkgs.writeShellScriptBin "emacs-ediff" ''

tests/modules/programs/jujutsu/empty-config.nix

@@ -7,5 +7,6 @@
 
   nmt.script = ''
     assertPathNotExists home-files/.config/jj/config.toml
+    assertPathNotExists "home-files/Library/Application Support/jj/config.toml"
   '';
 }

tests/modules/programs/jujutsu/example-config.nix

@@ -1,6 +1,12 @@
-{ config, ... }:
+{ config, pkgs, ... }:
 
-{
+let
+  configFile = if pkgs.stdenv.isDarwin then
+    "home-files/Library/Application Support/jj/config.toml"
+  else
+    "home-files/.config/jj/config.toml";
+
+in {
   programs.jujutsu = {
     enable = true;
     package = config.lib.test.mkStubPackage { };
@@ -13,9 +19,9 @@
   };
 
   nmt.script = ''
-    assertFileExists home-files/.config/jj/config.toml
+    assertFileExists "${configFile}"
     assertFileContent \
-      home-files/.config/jj/config.toml \
+      "${configFile}" \
       ${
         builtins.toFile "expected.toml" ''
           [user]