Remove tty error handler and simply point to print report on bad return

Author: José Valim

lib/mix/lib/mix/tasks/app.start.ex

@@ -27,19 +27,22 @@ defmodule Mix.Tasks.App.Start do
     end
 
     unless opts[:no_start] do
-      start(project)
+      start(project[:app])
     end
   end
 
-  def start(project) do
-    if app = project[:app] do
+  @doc false
+  def start(app) do
+    if app do
       case Application.Behaviour.start(app) do
         :ok -> :ok
-        { :error, {:bad_return, err}} ->
-          raise Exception.normalize(err)
+        { :error, { :bad_return, _ } } ->
+          raise Mix.Error, message: "Could not start application #{app}, please see report above"
         { :error, reason } ->
           raise Mix.Error, message: "Could not start application #{app}: #{inspect reason}"
       end
+    else
+      :error
     end
   end
 end

lib/mix/test/mix/tasks/app.start_test.exs

@@ -9,28 +9,30 @@ defmodule Mix.Tasks.App.StartTest do
     end
   end
 
-  defmodule BadReturnSample do
+  defmodule WrongElixirProject do
     def project do
-      [app: :bad_return_app, version: "0.1.0"]
-    end
-    # Configuration for the OTP application
-    def application do
-      [mod: { Mix.Tasks.App.StartTest.BadReturnApp, [] }]
+      [app: :error, version: "0.1.0", elixir: "~> 0.8.1"]
     end
   end
 
-  defmodule BadReturnApp do
-    use Application.Behaviour
-
-    def start(_type, _args) do
-      :bar # Bad return
+  setup config do
+    if config[:app] do
+      :error_logger.tty(false)
     end
+    :ok
   end
 
-  defmodule WrongElixirProject do
-    def project do
-      [app: :error, version: "0.1.0", elixir: "~> 0.8.1"]
+  teardown config do
+    if app = config[:app] do
+      :application.stop(app)
+      :application.unload(app)
     end
+    :ok
+  end
+
+  teardown do
+    :error_logger.tty(true)
+    :ok
   end
 
   test "recompiles project if elixir version changed" do
@@ -89,39 +91,50 @@ defmodule Mix.Tasks.App.StartTest do
     end
   end
 
-  test "start does nothing if project[:app] is nil" do
-    project = Mix.project
-    assert Mix.Tasks.App.Start.start(project) == nil
+  defmodule BadReturnSample do
+    def project do
+      [app: :bad_return_sample, version: "0.1.0"]
+    end
+
+    def application do
+      Process.get(:application_definition)
+    end
   end
 
-  test "start runs successfully in okay case" do
-    Mix.Project.push MixTest.Case.Sample
-    in_fixture "no_mixfile", fn ->
-      Mix.Tasks.Compile.run []
-      project = Mix.project
-      assert Mix.Tasks.App.Start.start(project) == :ok
+  defmodule BadReturnApp do
+    use Application.Behaviour
+
+    def start(_type, _args) do
+      :bad # Bad return
     end
   end
 
-  test "start raises an exception on :error" do
-    Mix.Project.push AppStartSample
+  test "start does nothing if app is nil" do
+    assert Mix.Tasks.App.Start.start(nil) == :error
+  end
 
+  @tag app: :bad_return_sample
+  test "start raises on :error" do
+    Mix.Project.push BadReturnSample
     in_fixture "no_mixfile", fn ->
-      project = Mix.project
-      assert_raise Mix.Error, fn ->
-        Mix.Tasks.App.Start.start(project)
+      Process.put(:application_definition, applications: [:unknown])
+      Mix.Tasks.Compile.run []
+
+      assert_raise Mix.Error, %r"Could not start application bad_return_sample: ", fn ->
+        Mix.Tasks.App.Start.start(:bad_return_sample)
       end
     end
   end
 
-  test "start raises a stacktrace on bad_return" do
+  @tag app: :bad_return_sample
+  test "start points to report on bad return" do
     Mix.Project.push BadReturnSample
-
     in_fixture "no_mixfile", fn ->
+      Process.put(:application_definition, mod: { BadReturnApp, [] })
       Mix.Tasks.Compile.run []
-      project = Mix.project
-      assert_raise ErlangError, fn ->
-        Mix.Tasks.App.Start.start(project)
+
+      assert_raise Mix.Error, %r"Could not start application bad_return_sample, please see report above", fn ->
+        Mix.Tasks.App.Start.start(:bad_return_sample)
       end
     end
   end