moduledoc for Topology

lib/topology.ex

@@ -1,6 +1,31 @@
 defmodule Strom.Topology do
   @moduledoc """
   Runs set of components. Restarts all of them in case of crash.
+  Provides `start`, `stop`, `call` function on the module level.
+  Starts topology as a process with the topology module name.
+  So only one topology with the given name can exist.
+
+      ## Example:
+      iex>  defmodule OddEvenTopology do
+      ...>    use Strom.Topology
+      ...>    alias Strom.Sink.Null
+      ...>
+      ...>    def topology(_opts) do
+      ...>      [
+      ...>        Source.new(:s1, [1, 2, 3]),
+      ...>        Source.new(:s2, [4, 5, 6]),
+      ...>        Mixer.new([:s1, :s2], :s),
+      ...>        Transformer.new(:s, &(&1 + 1)),
+      ...>        Splitter.new(:s, %{odd: &(rem(&1, 2) == 1), even: &(rem(&1, 2) == 0)}),
+      ...>        Sink.new(:odd, Null.new(), true)
+      ...>      ]
+      ...>    end
+      ...>  end
+      iex> OddEvenTopology.start()
+      iex> %{even: even} = OddEvenTopology.call(%{})
+      iex> OddEvenTopology.stop()
+      iex> Enum.sort(Enum.to_list(even))
+      [2, 4, 6]
   """
 
   defstruct pid: nil,
@@ -97,26 +122,17 @@ defmodule Strom.Topology do
   defmacro __using__(_opts) do
     quote do
       import Strom.DSL
+      alias Strom.{Composite, Mixer, Sink, Source, Splitter, Transformer, Topology}
 
-      def start(opts \\ []) do
-        Strom.Topology.start(__MODULE__, opts)
-      end
+      def start(opts \\ []), do: Topology.start(__MODULE__, opts)
 
-      def call(flow) when is_map(flow) do
-        Strom.Topology.call(flow, __MODULE__)
-      end
+      def call(flow) when is_map(flow), do: Topology.call(flow, __MODULE__)
 
-      def stop do
-        Strom.Topology.stop(__MODULE__)
-      end
+      def stop, do: Topology.stop(__MODULE__)
 
-      def info do
-        Strom.Topology.info(__MODULE__)
-      end
+      def info, do: Topology.info(__MODULE__)
 
-      def components do
-        Strom.Topology.components(__MODULE__)
-      end
+      def components, do: Topology.components(__MODULE__)
     end
   end
 end

test/topology_test.exs

@@ -1,6 +1,7 @@
 defmodule Strom.TopologyTest do
   use ExUnit.Case, async: true
-  alias Strom.{Mixer, Sink, Source, Splitter, Transformer}
+  doctest Strom.Topology
+
   alias Strom.Sink.Null
 
   defmodule MyTopology do
@@ -65,16 +66,19 @@ defmodule Strom.TopologyTest do
     end
 
     test "kill component" do
-      [source1 | _] = MyTopology.components()
+      topology = MyTopology.info()
+      [source1 | _] = topology.components
       %{even: even} = MyTopology.call(%{})
       assert Enum.sort(Enum.to_list(even)) == [2, 4, 6]
 
       Process.exit(source1.pid, :kill)
       Process.sleep(1)
-      [source1 | _] = MyTopology.components()
+
+      check_dead(topology)
+
       topology = MyTopology.info()
       assert Process.alive?(topology.pid)
-      assert Process.alive?(source1.pid)
+      check_alive(topology)
 
       %{even: even} = MyTopology.call(%{})
       assert Enum.sort(Enum.to_list(even)) == [2, 4, 6]