Stacks support no options

lib/divo/stack.ex

@@ -29,11 +29,13 @@ defmodule Divo.Stack do
 
     services =
       config
-      |> Enum.map(fn {module, envars} ->
-        apply(module, :gen_stack, [envars])
-      end)
+      |> Enum.map(&configure_stack/1)
       |> Enum.reduce(%{}, fn service, acc -> Map.merge(service, acc) end)
 
     Map.put(compose_file, :services, services)
   end
+
+  defp configure_stack(module) when is_atom(module), do: apply(module, :gen_stack, [[]])
+
+  defp configure_stack({module, envars}), do: apply(module, :gen_stack, [envars])
 end

mix.exs

@@ -4,7 +4,7 @@ defmodule Divo.MixProject do
   def project do
     [
       app: :divo,
-      version: "1.1.1",
+      version: "1.1.2",
       elixir: "~> 1.8",
       start_permanent: Mix.env() == :prod,
       deps: deps(),

test/file_test.exs

@@ -31,33 +31,32 @@ defmodule Divo.FileTest do
     assert Divo.File.ensure_file(config) == "/var/tmp/foo/divo.compose"
   end
 
-  test "generates compose file from a behaviour implementation" do
+  test "generates compose file from a behaviour implementation of a single service" do
     allow(File.write!(any(), any()), return: :ok)
     allow(System.get_env("TMPDIR"), return: "/var/tmp/bar")
 
-    services = [{DivoBarbaz, []}]
+    services = [{DivoFoobar, [db_password: "we-are-divo", db_name: "foobar-db", something: "else"]}]
 
     TemporaryEnv.put :divo, :divo, services do
       config = Divo.Helper.fetch_config()
 
       assert Divo.File.ensure_file(config) == "/var/tmp/bar/divo.compose"
     end
   end
-end
 
-defmodule DivoBarbaz do
-  @behaviour Divo.Stack
-
-  @impl Divo.Stack
-  def gen_stack(_envars) do
-    %{
-      barbaz: %{
-        image: "library/barbaz",
-        healthcheck: %{
-          test: ["CMD-SHELL", "/bin/true || exit 1"]
-        },
-        ports: ["2345:2345", "7777:7777"]
-      }
-    }
+  test "concatenates compose file from multiple implementations of the behaviour" do
+    allow(File.write!(any(), any()), return: :ok)
+    allow(System.get_env("TMPDIR"), return: "/var/tmp/bar")
+
+    services = [
+      {DivoFoobar, [db_password: "we-are-divo", db_name: "foobar-db", something: "else"]},
+      DivoBarbaz
+    ]
+
+    TemporaryEnv.put :divo, :divo, services do
+      config = Divo.Helper.fetch_config()
+
+      assert Divo.File.ensure_file(config) == "/var/tmp/bar/divo.compose"
+    end
   end
 end

test/stack_test.exs

@@ -2,7 +2,7 @@ defmodule Divo.StackTest do
   use ExUnit.Case
   require TemporaryEnv
 
-  test "behaviour returns the service definition" do
+  test "behaviour returns the service definition of a single stack" do
     services = [
       {DivoFoobar, [db_password: "we-are-divo", db_name: "foobar-db", something: "else"]}
     ]
@@ -29,6 +29,29 @@ defmodule Divo.StackTest do
 
     assert expected == actual
   end
+
+  test "behaviour returns the service definition of a stack with no parameters" do
+    services = [
+      DivoBarbaz
+    ]
+
+    expected = %{
+      version: "3.4",
+      services: %{
+        barbaz: %{
+          image: "library/barbaz",
+          ports: ["2345:2345", "7777:7777"],
+          healthcheck: %{
+            test: ["CMD-SHELL", "/bin/true || exit 1"]
+          }
+        }
+      }
+    }
+
+    actual = Divo.Stack.concat_compose(services)
+
+    assert expected == actual
+  end
 end
 
 defmodule DivoFoobar do
@@ -55,3 +78,20 @@ defmodule DivoFoobar do
     }
   end
 end
+
+defmodule DivoBarbaz do
+  @behaviour Divo.Stack
+
+  @impl Divo.Stack
+  def gen_stack(_envars) do
+    %{
+      barbaz: %{
+        image: "library/barbaz",
+        healthcheck: %{
+          test: ["CMD-SHELL", "/bin/true || exit 1"]
+        },
+        ports: ["2345:2345", "7777:7777"]
+      }
+    }
+  end
+end