3 files changed, 42 insertions, 0 deletions
diff --git a/lib/tests/modules/class-check.nix b/lib/tests/modules/class-check.nix
new file mode 100644
index 000000000000..6e02f8c30920
--- /dev/null
+++ b/lib/tests/modules/class-check.nix
@@ -0,0 +1,34 @@
+{ lib, ... }: {
+  config = {
+    _module.freeformType = lib.types.anything;
+    ok =
+      lib.evalModules {
+        specialArgs.class = "nixos";
+        modules = [
+          ./module-class-is-nixos.nix
+        ];
+      };
+
+    fail =
+      lib.evalModules {
+        specialArgs.class = "nixos";
+        modules = [
+          ./module-class-is-nixos.nix
+          ./module-class-is-darwin.nix
+        ];
+      };
+
+    fail-anon =
+      lib.evalModules {
+        specialArgs.class = "nixos";
+        modules = [
+          ./module-class-is-nixos.nix
+          { _file = "foo.nix#darwinModules.default";
+            class = "darwin";
+            imports = [];
+          }
+        ];
+      };
+
+  };
+}
diff --git a/lib/tests/modules/module-class-is-darwin.nix b/lib/tests/modules/module-class-is-darwin.nix
new file mode 100644
index 000000000000..d8b60203f707
--- /dev/null
+++ b/lib/tests/modules/module-class-is-darwin.nix
@@ -0,0 +1,4 @@
+{
+  class = "darwin";
+  config = {};
+}
diff --git a/lib/tests/modules/module-class-is-nixos.nix b/lib/tests/modules/module-class-is-nixos.nix
new file mode 100644
index 000000000000..04b6e860e890
--- /dev/null
+++ b/lib/tests/modules/module-class-is-nixos.nix
@@ -0,0 +1,4 @@
+{
+  class = "nixos";
+  config = {};
+}