Don't compile deps too many times

Author: ericmj

lib/mix/lib/mix/deps.ex

@@ -105,22 +105,25 @@ defmodule Mix.Deps do
   defdelegate children(), to: Mix.Deps.Retriever
 
   @doc """
-  Return all dependencies depending on the given dependencies.
+  Return all given dependencies and their depending dependencies.
   """
-  def depending(deps, all_deps // all)
+  def with_depending(deps, all_deps // all) do
+    deps ++ do_with_depending(deps, all_deps)
+      |> Enum.uniq(&(&1.app))
+  end
 
-  def depending([], _all_deps) do
+  defp do_with_depending([], _all_deps) do
     []
   end
 
-  def depending(deps, all_deps) do
+  defp do_with_depending(deps, all_deps) do
     dep_names = Enum.map(deps, fn dep -> dep.app end)
 
     parents = Enum.filter all_deps, fn dep ->
       Enum.any?(dep.deps, fn child_dep -> child_dep.app in dep_names end)
     end
 
-    parents ++ depending(parents, all_deps)
+    do_with_depending(parents, all_deps) ++ parents
   end
 
   @doc """

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

@@ -29,7 +29,8 @@ defmodule Mix.Tasks.Deps.Compile do
   """
 
   import Mix.Deps, only: [ all: 0, available?: 1, by_name: 2, compile_paths: 1,
-                           depending: 2, format_dep: 1, make?: 1, mix?: 1, rebar?: 1 ]
+                           with_depending: 2, format_dep: 1, make?: 1, mix?: 1,
+                           rebar?: 1 ]
 
   def run(args) do
     Mix.Project.get! # Require the project to be available
@@ -39,8 +40,8 @@ defmodule Mix.Tasks.Deps.Compile do
         do_run(Enum.filter(all, &available?/1), opts)
       { opts, tail, _ } ->
         all_deps = all
-        deps = by_name(tail, all_deps)
-        do_run(deps ++ depending(deps, all_deps), opts)
+        deps = by_name(tail, all_deps) |> with_depending(all_deps)
+        do_run(deps, opts)
     end
   end
 

lib/mix/lib/mix/tasks/deps.update.ex

@@ -22,7 +22,7 @@ defmodule Mix.Tasks.Deps.Update do
   """
 
   import Mix.Deps, only: [ all: 0, all: 2, available?: 1, by_name: 2,
-                           depending: 2, format_dep: 1 ]
+                           with_depending: 2, format_dep: 1 ]
 
   def run(args) do
     Mix.Project.get! # Require the project to be available
@@ -33,9 +33,10 @@ defmodule Mix.Tasks.Deps.Update do
         acc = all(init, &deps_updater/2)
       rest != [] ->
         all_deps = all
-        deps = Enum.map by_name(rest, all_deps), &check_unavailable!/1
-        deps = deps ++ depending(deps, all_deps)
-        { _, acc } = Enum.map_reduce deps, init, &deps_updater/2
+        deps = by_name(rest, all_deps)
+          |> Enum.map(&check_unavailable!/1)
+          |> with_depending(all_deps)
+        { _, acc } = Enum.map_reduce(deps, init, &deps_updater/2)
       true ->
         raise Mix.Error, message: "mix deps.update expects dependencies as arguments or " <>
                                   "the --all option to update all dependencies"

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

@@ -283,6 +283,8 @@ defmodule Mix.Tasks.DepsTest do
       assert_received { :mix_shell, :info, ["* Compiling deps_repo"] }
       assert_received { :mix_shell, :info, ["Generated git_repo.app"] }
 
+      Mix.Task.clear
+
       Mix.Tasks.Deps.Update.run ["--all"]
       assert_received { :mix_shell, :info, ["* Updating deps_repo (0.1.0) [path: \"custom/deps_repo\"]"] }
       assert_received { :mix_shell, :info, ["* Compiling deps_repo"] }