Fix plugins only specified in an environment

When specifying a plugin in an environment only (and not a release) the
plugin is prepended to the profile.plugins attribute. However since
this defaults to nil, the result is an improper list in the format:

    [SampleApp.TestPlugin | nil]

This commit fixes it so that the profile.plugins defaults to an empty
list, resulting in:

    [SampleApp.TestPlugin | []]

A test has been added which loads a sample plugin from the rel
directory and verifies that the list contains a list with the plugin.
This test will fail when the list is an improper list.

When merging the profile and environment, there is a check in place so
that lists are correctly merged together.

The integration test has been modified to ensure that all the plugins
run.

lib/mix/lib/releases/assembler.ex

@@ -62,6 +62,7 @@ defmodule Mix.Releases.Assembler do
     profile = Enum.reduce(env_profile, rel_profile, fn {k, v}, acc ->
       case v do
         nil -> acc
+        []  -> nil
         _   -> Map.put(acc, k, v)
       end
     end)

lib/mix/lib/releases/models/profile.ex

@@ -15,7 +15,7 @@ defmodule Mix.Releases.Profile do
     include_src: nil, # boolean
     include_system_libs: nil, # boolean | "path/to/libs"
     strip_debug_info: nil, # boolean
-    plugins: nil, # list of module names
+    plugins: [], # list of module names
     overlay_vars: nil, # keyword list
     overlays: nil, # overlay list
     overrides: nil, # override list [app: app_path]

test/config_test.exs

@@ -38,4 +38,18 @@ defmodule ConfigTest do
                      default_release: :default, default_environment: :default} = config
     end
   end
+
+  describe "plugin config" do
+    test "read!" do
+      config = Mix.Project.in_project(:standard_app, @standard_app, fn _mixfile ->
+        Mix.Releases.Config.read!(Path.join([@standard_app, "rel", "config.exs"]))
+      end)
+      assert %Config{environments: %{
+                        dev: %Environment{profile: %Profile{plugins: []}},
+                        prod: %Environment{profile: %Profile{plugins: [SampleApp.ProdPlugin]}}},
+                     releases: %{
+                       standard_app: %Release{profile: %Profile{plugins: [SampleApp.ReleasePlugin]}}}
+      } = config
+    end
+  end
 end

test/fixtures/standard_app/rel/config.exs

@@ -1,3 +1,5 @@
+Code.require_file("rel/sample_app_plugin.ex")
+Code.require_file("rel/release_plugin.ex")
 use Mix.Releases.Config,
   default_environment: :dev
 
@@ -10,8 +12,10 @@ environment :prod do
   set dev_mode: false
   set strip_debug_info: false
   set include_erts: true
+  plugin SampleApp.ProdPlugin
 end
 
 release :standard_app do
   set version: "0.0.1"
+  plugin SampleApp.ReleasePlugin
 end

test/fixtures/standard_app/rel/release_plugin.ex

@@ -0,0 +1,10 @@
+defmodule SampleApp.ReleasePlugin do
+  use Mix.Releases.Plugin
+
+  def before_assembly(_), do: info("Release Plugin - before_assembly") && nil
+  def after_assembly(_), do: info("Release Plugin - after_assembly") && nil
+
+  def before_package(_), do: info("Release Plugin - before_package") && nil
+  def after_package(_), do: info("Release Plugin - after_package") && nil
+ def after_cleanup(_), do: info("Release Plugin - after_cleanup") && nil
+end

test/fixtures/standard_app/rel/sample_app_plugin.ex

@@ -0,0 +1,10 @@
+defmodule SampleApp.ProdPlugin do
+  use Mix.Releases.Plugin
+
+  def before_assembly(_), do: info("Prod Plugin - before_assembly") && nil
+  def after_assembly(_), do: info("Prod Plugin - after_assembly") && nil
+
+  def before_package(_), do: info("Prod Plugin - before_package") && nil
+  def after_package(_), do: info("Prod Plugin - after_package") && nil
+  def after_cleanup(_), do: info("Prod Plugin - after_cleanup") && nil
+end

test/integration_test.exs

@@ -16,10 +16,10 @@ defmodule IntegrationTest do
       File.cd!(@standard_app_path)
       {:ok, _} = File.rm_rf(Path.join(@standard_app_path, "_build"))
       _ = File.rm(Path.join(@standard_app_path, "mix.lock"))
-      :ok = mix("deps.get")
-      :ok = mix("deps.compile", ["distillery"])
-      :ok = mix("compile")
-      :ok = mix("release.clean")
+      {:ok, _} = mix("deps.get")
+      {:ok, _} = mix("deps.compile", ["distillery"])
+      {:ok, _} = mix("compile")
+      {:ok, _} = mix("release.clean")
       unquote(body)
       File.cd!(old_dir)
     end
@@ -42,12 +42,17 @@ defmodule IntegrationTest do
         # Build release
         result = mix("release", ["--verbose", "--env=prod"])
         r = case result do
-          :ok -> :ok
+          {:ok, output} -> {:ok, output}
           {:error, _code, output} ->
             IO.puts(output)
             :error
         end
-        assert :ok = r
+        assert {:ok, output} = r
+        for callback <- ~w(before_assembly after_assembly before_package after_package) do
+          assert output =~ "Prod Plugin - #{callback}"
+        end
+        refute String.contains?(output, "Release Plugin")
+
         assert ["0.0.1"] == Utils.get_release_versions(@standard_output_path)
         # Boot it, ping it, and shut it down
         assert {:ok, tmpdir} = Utils.insecure_mkdir_temp()
@@ -80,12 +85,12 @@ defmodule IntegrationTest do
         # Build v1 release
         result = mix("release", ["--verbose", "--env=prod"])
         r = case result do
-              :ok -> :ok
+              {:ok, output} -> {:ok, output}
               {:error, _code, output} ->
                 IO.puts(output)
                 :error
             end
-        assert :ok = r
+        assert {:ok, _output} = r
         # Update config for v2
         project_config_path = Path.join(@standard_app_path, "mix.exs")
         project = File.read!(project_config_path)
@@ -122,15 +127,15 @@ defmodule IntegrationTest do
         File.write!(a_mod_path, new_a_mod)
         File.write!(b_mod_path, new_b_mod)
         # Build v2 release
-        :ok = mix("compile")
+        {:ok, _} = mix("compile")
         result = mix("release", ["--verbose", "--env=prod", "--upgrade"])
         r = case result do
-              :ok -> :ok
+              {:ok, output} -> {:ok, output}
               {:error, _code, output} ->
                 IO.puts(output)
                 :error
             end
-        assert :ok = r
+        assert {:ok, _} = r
         assert ["0.0.2", "0.0.1"] == Utils.get_release_versions(@standard_output_path)
         # Deploy it
         assert {:ok, tmpdir} = Utils.insecure_mkdir_temp()
@@ -214,7 +219,7 @@ defmodule IntegrationTest do
         if System.get_env("VERBOSE_TESTS") do
           IO.puts(output)
         end
-        :ok
+        {:ok, output}
       {output, err} -> {:error, err, output}
     end
   end