quality/tres: Add handler testcases

lib/tres/example_handler.ex

@@ -7,33 +7,50 @@ defmodule Tres.ExampleHandler do
   defmodule State do
     defstruct datapath_id: nil,
               aux_id: nil,
-              conn_ref: nil
+              queue: :queue.new(),
+              client: nil
+  end
+
+  # API functions
+
+  @spec send(String.t(), map()) :: :ok
+  def send(datapath_id, msg), do: send_message(msg, datapath_id)
+
+  @spec get(datapath_id :: String.t()) :: map() | nil
+  def get(datapath_id) do
+    datapath_id
+    |> lookup_handler_pid()
+    |> GenServer.call(:get)
   end
 
   def start_link(datapath, args) do
     GenServer.start_link(__MODULE__, [datapath, args])
   end
 
+  # GenServer callbacks
+
   def init([{datapath_id, aux_id}, _args]) do
-    info(
-      "Switch Ready: " <>
-        "datapath_id: #{datapath_id} " <> "aux_id: #{aux_id} " <> "on #{inspect(self())}"
-    )
-
-    _ = send_desc_stats_request(datapath_id)
-    _ = send_port_desc_stats_request(datapath_id)
-    state = %State{datapath_id: datapath_id, aux_id: aux_id}
-    {:ok, state}
+    :ok = info("datapath connected: #{datapath_id}")
+    :ok = send_flow_mod_add(datapath_id, priority: 0)
+    {:ok, %State{datapath_id: datapath_id, aux_id: aux_id}}
   end
 
-  def handle_info(%PortDesc.Reply{datapath_id: datapath_id} = desc, state) do
-    handle_port_desc_stats_reply(desc, datapath_id)
-    {:noreply, state}
+  def handle_call(:get, from, %State{queue: {[], []}} = state) do
+    {:noreply, %{state | client: from}}
   end
 
-  def handle_info(%Desc.Reply{datapath_id: datapath_id} = desc, state) do
-    handle_desc_stats_reply(desc, datapath_id)
-    {:noreply, state}
+  def handle_call(:get, _from, %State{} = state) do
+    {{:value, msg}, new_queue} = :queue.out(state.queue)
+    {:reply, msg, %{state | queue: new_queue}}
+  end
+
+  def handle_info(%{datapath_id: _datapath_id} = msg, %State{client: nil} = state) do
+    {:noreply, %{state | queue: :queue.in(msg, state.queue)}}
+  end
+
+  def handle_info(%{datapath_id: _datapath_id} = msg, state) do
+    GenServer.reply(state.client, msg)
+    {:noreply, %{state | client: nil}}
   end
 
   def handle_info({:switch_disconnected, _reason}, state) do
@@ -41,47 +58,10 @@ defmodule Tres.ExampleHandler do
     {:stop, :normal, state}
   end
 
-  def handle_info({:switch_hang, _datapath_id}, state) do
-    :ok = warn("Switch possible hang: datapath_id: #{state.datapath_id}")
-    {:noreply, state}
-  end
-
-  # `Catch all` function is required.
   def handle_info(info, state) do
     :ok = warn("unhandled message #{inspect(info)}: #{state.datapath_id}")
     {:noreply, state}
   end
 
   # private functions
-
-  defp send_desc_stats_request(datapath_id) do
-    Desc.Request.new()
-    |> send_message(datapath_id)
-  end
-
-  defp send_port_desc_stats_request(datapath_id) do
-    PortDesc.Request.new()
-    |> send_message(datapath_id)
-  end
-
-  defp handle_desc_stats_reply(desc, datapath_id) do
-    info(
-      "Switch Desc: " <>
-        "mfr = #{desc.mfr_desc} " <>
-        "hw = #{desc.hw_desc} " <> "sw = #{desc.sw_desc} " <> "for #{datapath_id}"
-    )
-  end
-
-  defp handle_port_desc_stats_reply(port_desc, datapath_id) do
-    for port <- port_desc.ports do
-      info(
-        "Switch has port: " <>
-          "number = #{port.number} " <>
-          "hw_addr = #{port.hw_addr} " <>
-          "name = #{port.name} " <>
-          "config = #{inspect(port.config)} " <>
-          "current_speed = #{port.current_speed} " <> "on #{datapath_id}"
-      )
-    end
-  end
 end