💚 Add tests for

test/lib/elven_gard/protocol_test.exs

@@ -0,0 +1,39 @@
+defmodule ElvenGard.ProtocolTest do
+  use ExUnit.Case
+
+  defmodule BasicType do
+    use ElvenGard.Type
+
+    @impl ElvenGard.Type
+    def encode(val, _opts), do: val
+
+    @impl ElvenGard.Type
+    def decode(val, _opts), do: val
+  end
+
+  describe "Protocol raise error if:" do
+    test "encode/1 is not defined" do
+      needle = ~r"function encode/1 required by behaviour"
+
+      assert_raise RuntimeError, needle, fn ->
+        defmodule Test do
+          use ElvenGard.Protocol
+
+          def decode(x), do: x
+        end
+      end
+    end
+
+    test "decode/1 is not defined" do
+      needle = ~r"function decode/1 required by behaviour"
+
+      assert_raise RuntimeError, needle, fn ->
+        defmodule Test do
+          use ElvenGard.Protocol
+
+          def encode(x), do: x
+        end
+      end
+    end
+  end
+end