quality: Add test cases for meter_mod message

test/ofp_meter_mod_test.exs

@@ -0,0 +1,44 @@
+defmodule OfpMeterModTest do
+  use ExUnit.Case
+  doctest Openflow
+
+  describe "Openflow.MeterMod" do
+    test "with packet_data" do
+      meter_mod =
+        "test/packet_data/libofproto-OFP13-meter_mod.packet"
+        |> File.read!()
+        |> Openflow.read()
+        |> Kernel.elem(1)
+        |> Map.to_list()
+        |> Openflow.MeterMod.new()
+        |> Openflow.to_binary()
+        |> Openflow.read()
+        |> Kernel.elem(1)
+
+      expect =
+        Openflow.MeterMod.new(
+          xid: 0,
+          meter_id: 100,
+          command: :add,
+          flags: [:pktps, :burst, :stats],
+          bands: [
+            Openflow.MeterBand.Drop.new(
+              burst_size: 10,
+              rate: 1000
+            ),
+            Openflow.MeterBand.Remark.new(
+              burst_size: 10,
+              prec_level: 1,
+              rate: 1000
+            )
+          ]
+        )
+
+      assert expect.xid == meter_mod.xid
+      assert expect.meter_id == meter_mod.meter_id
+      assert expect.command == meter_mod.command
+      assert expect.flags == meter_mod.flags
+      assert expect.bands == meter_mod.bands
+    end
+  end
+end