Remove pre-copying of dev dependencies

The current code was copying manifests but they got
recent access times which caused bugs. Also, a dependency
can have different results depending on each dependencies
are available and which are not, so simply copying the
compiled dep can lead to weird errors.

Author: José Valim

lib/elixir/lib/module/locals_tracker.ex

@@ -34,8 +34,8 @@
 defmodule Module.LocalsTracker do
   @moduledoc false
 
-  @timeout  30_000
-  @behavior :gen_server
+  @timeout   30_000
+  @behaviour :gen_server
 
   @type ref :: pid | module
   @type name :: atom

lib/mix/lib/mix/tasks/deps.compile.ex

@@ -58,7 +58,7 @@ defmodule Mix.Tasks.Deps.Compile do
           not nil?(opts[:compile]) ->
             do_compile dep
           mix?(dep) ->
-            do_mix dep, config
+            do_mix dep
           rebar?(dep) ->
             do_rebar dep, config
           make?(dep) ->
@@ -84,17 +84,8 @@ defmodule Mix.Tasks.Deps.Compile do
     :ok
   end
 
-  defp do_mix(Mix.Dep[app: app] = dep, config) do
+  defp do_mix(dep) do
     Mix.Deps.in_dependency dep, fn _ ->
-      case dev_compilation(app, config) do
-        { source, target } ->
-          File.rm_rf!(target)
-          File.mkdir_p!(target)
-          File.cp_r!(source, Path.dirname(target))
-        false ->
-          :ok
-      end
-
       try do
         res = Mix.Task.run("compile", ["--no-deps"])
         :ok in List.wrap(res)
@@ -109,21 +100,6 @@ defmodule Mix.Tasks.Deps.Compile do
     end
   end
 
-  # In case we have build per environments and the dependency was already
-  # compiled for development and the target is stale compared to the
-  # development (source) one, we simply copy the source to target and do
-  # the compilation on top of it.
-  defp dev_compilation(app, config) do
-    if config[:build_per_environment] do
-      source = config[:build_path] |> Path.dirname |> Path.join("dev/lib/#{app}")
-      target = Mix.Project.manifest_path
-      source != target && Mix.Deps.Lock.mix_env(source) == to_string(Mix.env) &&
-        not Mix.Utils.stale?([target], [source]) && { source, target }
-    else
-      false
-    end
-  end
-
   defp do_rebar(Mix.Dep[app: app] = dep, config) do
     do_command dep, rebar_cmd(app), "compile skip_deps=true deps_dir=#{inspect config[:deps_path]}"
   end
@@ -143,7 +119,7 @@ defmodule Mix.Tasks.Deps.Compile do
     end
 
     Mix.Task.run "local.rebar", []
-    Mix.Rebar.local_rebar_cmd || raise Mix.Error, message: "rebar instalation failed"
+    Mix.Rebar.local_rebar_cmd || raise Mix.Error, message: "rebar installation failed"
   end
 
   defp do_make(dep) do

lib/mix/test/mix/tasks/deps_test.exs

@@ -27,7 +27,7 @@ defmodule Mix.Tasks.DepsTest do
     end
   end
 
-  defmodule PerEnvironemtDepsApp do
+  defmodule PerEnvironmentDepsApp do
     def project do
       [ app: :sample, version: "0.1.0", build_per_environment: true,
         deps: [
@@ -154,7 +154,7 @@ defmodule Mix.Tasks.DepsTest do
   end
 
   test "compiles and prunes builds per environment" do
-    Mix.Project.push PerEnvironemtDepsApp
+    Mix.Project.push PerEnvironmentDepsApp
 
     in_fixture "deps_status", fn ->
       Mix.Tasks.Deps.Compile.run []
@@ -167,75 +167,14 @@ defmodule Mix.Tasks.DepsTest do
 
       Mix.ProjectStack.post_config [deps: []]
       Mix.Project.pop
-      Mix.Project.push PerEnvironemtDepsApp
+      Mix.Project.push PerEnvironmentDepsApp
 
       Mix.Tasks.Deps.Check.run []
       refute File.exists?("_build/dev/lib/ok/ebin/ok.app")
       assert File.exists?("_build/dev/lib/sample/ebin/sample.app")
     end
   end
 
-  test "copies dev dependency when building per environment" do
-    Mix.Project.push PerEnvironemtDepsApp
-
-    in_fixture "deps_status", fn ->
-      File.mkdir_p!("deps/ok/lib")
-      File.write!("deps/ok/lib/empty.ex", "")
-
-      Mix.Tasks.Deps.Compile.run []
-      assert File.exists?("_build/dev/lib/ok/ebin/ok.app")
-      assert_received { :mix_shell, :info, ["Generated ok.app"] }
-
-      Mix.Task.clear
-      Mix.env(:test)
-      Mix.Project.pop
-      Mix.Project.push PerEnvironemtDepsApp
-
-      Mix.Tasks.Deps.Compile.run []
-      assert File.exists?("_build/test/lib/ok/ebin/ok.app")
-      assert File.read!("_build/test/lib/ok/priv/sample") == "SAMPLE"
-      # We don't get a message becaused we copied the contents over
-      refute_received { :mix_shell, :info, ["Generated ok.app"] }
-    end
-  end
-
-  test "does not choke when another environment is compiled first than dev" do
-    Mix.Project.push PerEnvironemtDepsApp
-    Mix.env(:test)
-
-    in_fixture "deps_status", fn ->
-      File.mkdir_p!("deps/ok/lib")
-      File.write!("deps/ok/lib/empty.ex", "")
-
-      Mix.Tasks.Deps.Compile.run []
-      assert File.exists?("_build/test/lib/ok/ebin/ok.app")
-      assert File.read!("_build/test/lib/ok/priv/sample") == "SAMPLE"
-      assert_received { :mix_shell, :info, ["Generated ok.app"] }
-    end
-  end
-
-  test "does not copy if environments do not match" do
-    Mix.ProjectStack.post_config(deps: [{ :ok, "0.1.0", path: "deps/ok", env: Mix.env }])
-    Mix.Project.push PerEnvironemtDepsApp
-
-    in_fixture "deps_status", fn ->
-      File.mkdir_p!("deps/ok/lib")
-      File.write!("deps/ok/lib/empty.ex", "")
-
-      Mix.Tasks.Deps.Compile.run []
-      assert File.exists?("_build/dev/lib/ok/ebin/ok.app")
-      assert_received { :mix_shell, :info, ["Generated ok.app"] }
-
-      Mix.Task.clear
-      Mix.env(:test)
-      Mix.Project.pop
-      Mix.Project.push PerEnvironemtDepsApp
-
-      Mix.Tasks.Deps.Compile.run []
-      assert_received { :mix_shell, :info, ["Generated ok.app"] }
-    end
-  end
-
   test "unlocks all deps" do
     Mix.Project.push DepsApp
     in_fixture "no_mixfile", fn ->