openflow: Fix aggregate request

test/lib/openflow/ofp_group_mod_test.exs

@@ -0,0 +1,38 @@
+defmodule OfpGroupModTest do
+  use ExUnit.Case
+  doctest Openflow
+
+  describe "Openflow.read/1" do
+    test "with OFP_GROUP_MOD packet" do
+      binary = File.read!("test/packet_data/4-21-ofp_group_mod.packet")
+      {:ok, _group_mod, ""} = Openflow.read(binary)
+
+      group_mod =
+        binary
+        |> Openflow.read()
+        |> elem(1)
+        |> Map.to_list()
+        |> Openflow.GroupMod.new()
+        |> Openflow.to_binary()
+        |> Openflow.read()
+        |> elem(1)
+
+      assert group_mod.version == 4
+      assert group_mod.xid == 0
+      assert group_mod.command == :add
+      assert group_mod.type == :all
+      assert group_mod.group_id == 1
+
+      assert group_mod.buckets == [
+               Openflow.Bucket.new(
+                 weight: 1,
+                 watch_port: 1,
+                 watch_group: 1,
+                 actions: [Openflow.Action.Output.new(2)]
+               )
+             ]
+
+      assert Openflow.to_binary(group_mod) == binary
+    end
+  end
+end