default-specialisation: add test for default specialisation

modules/misc/specialisation.nix

@@ -11,8 +11,7 @@ in {
     type = types.attrsOf (types.submodule {
       options = {
         configuration = mkOption {
-          type =
-            let
+          type = let
             extended = extendModules {
               modules = [{
                 # Prevent infinite recursion
@@ -26,8 +25,7 @@ in {
                 _module.args.name = mkForce name;
               }];
             };
-            in
-            extended.type;
+          in extended.type;
           default = { };
           visible = "shallow";
           description = ''
@@ -89,22 +87,18 @@ in {
       message = "There can only be one default specialisation";
     }];
 
-    home.extraBuilderCommands =
-      let
+    home.extraBuilderCommands = let
       link = n: v:
         let pkg = v.configuration.home.activationPackage;
         in "ln -s ${pkg} $out/specialisation/${n}";
-      in
-      ''
+    in ''
       mkdir $out/specialisation
       ${concatStringsSep "\n" (mapAttrsToList link cfg)}
     '';
 
-    home.activation =
-      let
+    home.activation = let
       defaultSpecialisation = findFirst (s: s.default) null (attrValues cfg);
-      in
-      mkIf (defaultSpecialisation != null) (mkForce {
+    in mkIf (defaultSpecialisation != null) (mkForce {
       activateSpecialisation = ''
         ${defaultSpecialisation.configuration.home.activationPackage}/activate
       '';

tests/modules/misc/specialisation/default-specialisation.nix

@@ -0,0 +1,10 @@
+{ config, ... }: {
+  home.file.testfile.text = "not special";
+  specialisation = { test.default = true; };
+
+  nmt.script = ''
+    assertFileExists activate
+    assertFileContains activate \
+      "${config.specialisation.test.configuration.home.activationPackage}/activate"
+  '';
+}

tests/modules/misc/specialisation/default.nix

@@ -1 +1,4 @@
-{ specialisation = ./specialisation.nix; }
+{
+  specialisation = ./specialisation.nix;
+  default-specialisation = ./default-specialisation.nix;
+}