Add Mix.Project.deps_paths

Signed-off-by: José Valim <jose.valim@plataformatec.com.br>

Author: José Valim

lib/mix/lib/mix/project.ex

@@ -236,6 +236,22 @@ defmodule Mix.Project do
     Path.expand config[:deps_path]
   end
 
+  @doc """
+  Returns the full path of all dependencies as a map.
+
+  ## Examples
+
+      Mix.Project.deps_paths
+      #=> %{foo: "deps/foo", bar: "custom/path/dep"}
+
+  """
+  @spec deps_paths() :: %{atom => Path.t}
+  def deps_paths do
+    Enum.reduce Mix.Dep.loaded(env: Mix.env), %{}, fn
+      %{app: app, opts: opts}, acc -> Map.put acc, app, opts[:dest]
+    end
+  end
+
   @doc """
   Returns the build path for this project.
 

lib/mix/test/mix/dep_test.exs

@@ -53,6 +53,17 @@ defmodule Mix.DepTest do
     end
   end
 
+  test "extracts all dependencies paths from the given project" do
+    Mix.Project.push DepsApp
+
+    in_fixture "deps_status", fn ->
+      paths = Mix.Project.deps_paths
+      assert map_size(paths) == 6
+      assert paths[:ok] =~ "deps/ok"
+      assert paths[:uncloned] =~ "deps/uncloned"
+    end
+  end
+
   test "fails on invalid dependencies" do
     assert_wrong_dependency [{:ok}]
     assert_wrong_dependency [{:ok, nil}]