Fix mix dialyzer warnings and improve task specs

Author: fishcakez

lib/mix/lib/mix/archive.ex

@@ -66,6 +66,7 @@ defmodule Mix.Archive do
     {:ok, _} = :zip.create(String.to_char_list(target_path),
                   files_to_add(source_path, dir),
                   uncompress: ['.beam', '.app'])
+    :ok
   end
 
   defp files_to_add(path, dir) do

lib/mix/lib/mix/compilers/elixir.ex

@@ -157,7 +157,7 @@ defmodule Mix.Compilers.Elixir do
 
   defp remove_stale_entries([{beam, module, source, _d, _f} = entry|t], changed, removed, acc) do
     if source in changed do
-      File.rm(beam)
+      _ = File.rm(beam)
       remove_stale_entries(t, changed, [module|removed], acc)
     else
       remove_stale_entries(t, changed, removed, [entry|acc])

lib/mix/lib/mix/task.ex

@@ -307,7 +307,7 @@ defmodule Mix.Task do
     Mix.TasksServer.delete_many([{:task, task, proj},
                                  {:alias, task, proj}])
 
-    if (module = get(task)) && recursive(module) && Mix.Project.umbrella? do
+   _ = if (module = get(task)) && recursive(module) && Mix.Project.umbrella? do
       recur fn proj ->
         Mix.TasksServer.delete_many([{:task, task, proj},
                                      {:alias, task, proj}])

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

@@ -17,6 +17,7 @@ defmodule Mix.Tasks.App.Start do
     * `--no-start`      - do not start applications after compilation
 
   """
+  @spec run(OptionParser.argv) :: :ok
   def run(args) do
     Mix.Project.get!
     Mix.Task.run "loadpaths", ["--no-readd"|args]

lib/mix/lib/mix/tasks/archive.build.ex

@@ -30,7 +30,7 @@ defmodule Mix.Tasks.Archive.Build do
       Only applies when `mix.exs` is available.
 
   """
-
+  @spec run(OptionParser.argv) :: :ok
   def run(args) do
     {opts, _, _} = OptionParser.parse(args, aliases: [o: :output, i: :input],
                                       switches: [force: :boolean, compile: :boolean])

lib/mix/lib/mix/tasks/archive.ex

@@ -15,7 +15,7 @@ defmodule Mix.Tasks.Archive do
   variable to different locations based on a particular
   Elixir installation.
   """
-
+  @spec run(OptionParser.argv) :: :ok
   def run(_) do
     archives =
       Mix.Local.archives_path

lib/mix/lib/mix/tasks/archive.uninstall.ex

@@ -9,7 +9,7 @@ defmodule Mix.Tasks.Archive.Uninstall do
       mix archive.uninstall archive.ez
 
   """
-
+  @spec run(OptionParser.argv) :: :ok
   def run(argv) do
     {_, argv, _} = OptionParser.parse(argv)
 

lib/mix/lib/mix/tasks/clean.ex

@@ -16,6 +16,7 @@ defmodule Mix.Tasks.Clean do
 
   @switches [deps: :boolean, only: :string]
 
+  @spec run(OptionParser.argv) :: :ok
   def run(args) do
     Mix.Project.get!
     loadpaths!

lib/mix/lib/mix/tasks/cmd.ex

@@ -15,6 +15,7 @@ defmodule Mix.Tasks.Cmd do
   Aborts when the first command exits with status different
   than zero.
   """
+  @spec run(OptionParser.argv) :: :ok
   def run(args) do
     case Mix.shell.cmd(Enum.join(args, " ")) do
       0 -> :ok

lib/mix/lib/mix/tasks/compile.app.ex

@@ -58,6 +58,7 @@ defmodule Mix.Tasks.Compile.App do
     * `--force` - forces compilation regardless of modification times
 
   """
+  @spec run(OptionParser.argv) :: :ok | :noop
   def run(args) do
     {opts, _, _} = OptionParser.parse(args, switches: [force: :boolean])