Add metric registration/config to wobserver application.

lib/wobserver.ex

@@ -4,15 +4,18 @@ defmodule Wobserver do
   """
 
   alias Wobserver.Page
+  alias Wobserver.Util.Metrics
 
   @doc ~S"""
   Registers external application to integrate with `:wobserver`.
 
   The following can be registered:
     - `:page`, see: `Wobserver.Page.register/1`.
+    - `:metric`, see: `Wobserver.Util.Metrics.register/1`.
   """
   @spec register(:page, page :: Page.data) :: boolean
   def register(:page, page), do: Page.register(page)
+  def register(:metric, metric), do: Metrics.register(metric)
 
   @doc ~S"""
   Information about Wobserver.

lib/wobserver/application.ex

@@ -6,7 +6,9 @@ defmodule Wobserver.Application do
   use Application
 
   alias Plug.Adapters.Cowboy
+
   alias Wobserver.Page
+  alias Wobserver.Util.Metrics
 
   @spec port :: integer
   def port do
@@ -20,6 +22,7 @@ defmodule Wobserver.Application do
   def start(_type, _args) do
     # Load pages and metrics from config
     Page.load_config
+    Metrics.load_config
 
     # Start cowboy
     import Supervisor.Spec, warn: false

test/wobserver_test.exs

@@ -2,6 +2,7 @@ defmodule WobserverTest do
   use ExUnit.Case
 
   alias Wobserver.Page
+  alias Wobserver.Util.Metrics
 
   describe "about" do
     test "includes name" do
@@ -44,5 +45,19 @@ defmodule WobserverTest do
 
       assert Page.call(:test) == 5
     end
+
+    test "registers a metric" do
+      assert Wobserver.register :metric, [example: {fn -> [{5, []}] end, :gauge, "Description"}]
+
+      assert Keyword.has_key?(Metrics.overview, :example)
+    end
+
+    test "registers a metric generator" do
+      assert Wobserver.register :metric, [
+        fn -> [generated: {fn -> [{5, []}] end, :gauge, "Description"}] end
+      ]
+
+      assert Keyword.has_key?(Metrics.overview, :generated)
+    end
   end
 end