1 files changed, 33 insertions, 0 deletions
diff --git a/test/lithium_spf_test.exs b/test/lithium_spf_test.exs
new file mode 100644
index 0000000..9843009
--- /dev/null
+++ b/test/lithium_spf_test.exs
@@ -0,0 +1,33 @@
+# SPDX-FileCopyrightText: 2025 Johannes Christ
+# SPDX-License-Identifier: AGPL-3.0-or-later
+defmodule :lithium_spf_test do
+  use ExUnit.Case
+
+  @ip {127, 0, 0, 127}
+  @sender ~c"mike@localhost"
+
+  defp check_domain(domain) do
+    :lithium_spf.check_host(@ip, domain, @sender)
+  end
+
+  describe "domain validation" do
+    test "rejects empty domain" do
+      assert {:none, [invalid_domain: :not_multi_label]} = check_domain(~c"")
+    end
+
+    test "rejects empty label" do
+      assert {:none, [invalid_domain: :label_empty]} = check_domain(~c".host")
+    end
+
+    test "rejects non-multi label domain name" do
+      assert {:none, [invalid_domain: :not_multi_label]} = check_domain(~c"host")
+    end
+
+    test "rejects too long label" do
+      over_sixty_three_chars =
+        ~c"hellojoehellomikesystemworkingseemstobeokayfineletrytrathatagainbutintroduceabug.localhost"
+
+      assert {:none, [invalid_domain: :label_too_long]} = check_domain(over_sixty_three_chars)
+    end
+  end
+end