Provide iex -S mix instead of mix iex

In order for iex to work reliably, we need it to pass special
parameters to the Erlang VM. Therefore, it cannot be started
via a regular Elixir script, as in `mix iex`.

Therefore, we need to use `iex -S mix` which first boots iex
and then run the given mix commands.

Closes #692

Author: José Valim

CHANGELOG.md

@@ -30,6 +30,7 @@
   * [File] Deprecate path related functions in favor of the module `Path`
   * [Kernel] The `/>` operator has been deprecated in favor of `|>`
   * [Mix] `Mix.Project.sources` is deprecated in favor of `Mix.Project.config_files`
+  * [Mix] `mix iex` is no longer functional, please use `iex -S mix`
   * [OptionParser] `:flags` option was deprecated in favor of `:switches` to support many types
 
 # v0.7.2 (2012-12-04)

bin/mix

@@ -1,17 +1,3 @@
-#!/bin/sh
-readlink_f () {
-  cd "$(dirname "$1")" > /dev/null
-  local filename="$(basename "$1")"
-  if [ -h "$filename" ]; then
-    readlink_f "$(readlink "$filename")"
-  else
-    echo "`pwd -P`/$filename"
-  fi
-}
-
-SELF=$(readlink_f "$0")
-SCRIPT_PATH=$(dirname "$SELF")
-EXECUTABLE="elixir"
-
-if [ "$1" = "iex" ]; then EXECUTABLE="iex"; fi
-exec "$SCRIPT_PATH"/$EXECUTABLE -e "Mix.start; Mix.CLI.run" -- "$@"
+#!/usr/bin/env elixir
+Mix.start
+Mix.CLI.run

bin/mix.bat

@@ -1,10 +1 @@
-@echo off
-if "%1" == "iex" (
-  goto iex
-) else (
-  goto elixir
-)
-:iex
-call "%~dp0\iex.bat" -e "Mix.start" -e "Mix.CLI.run" -- %*
-:elixir
-call "%~dp0\elixir.bat" -e "Mix.start" -e "Mix.CLI.run" -- %*
+call "%~dp0\elixir.bat" "%~dp0\mix" %*

lib/mix/lib/mix/cli.ex

@@ -34,7 +34,7 @@ defmodule Mix.CLI do
   end
 
   defp get_task([]) do
-    { Mix.project[:default] || "test", [] }
+    { Mix.project[:default_task] || "compile", [] }
   end
 
   defp run_task(name, args) do

lib/mix/lib/mix/project.ex

@@ -138,7 +138,7 @@ defmodule Mix.Project do
     [ compile_path: "ebin",
       elixirc_exts: [:ex],
       default_env: [test: :test],
-      default_task: "test",
+      default_task: "compile",
       deps_path: "deps",
       erlc_paths: ["src"],
       lockfile: "mix.lock",

lib/mix/lib/mix/tasks/iex.ex

@@ -1,27 +1,9 @@
 defmodule Mix.Tasks.Iex do
   use Mix.Task
+  @moduledoc false
 
-  @shortdoc "Start IEx with your project's settings"
-
-  @moduledoc """
-  Starts an iex repl with your project settings.
-
-  Before starting IEx, it invokes the prepare task
-  which defaults to compile and load your project.
-
-  ## Command line options
-
-  * `--no-compile` - do not compile even if files require compilation;
-  * `--no-start` - do not start applications after compilation;
-
-  """
-  def run(args) do
-    Mix.Task.run Mix.project[:prepare_task], args
-
-    unless IEx.started? do
-      raise Mix.Error, message: "could not start IEx. Due to booting constraints, " <>
-        "IEx needs to be started on its own, like `mix iex` and it cannot be mixed " <>
-        "with other tasks as in `mix do compile, iex`"
-    end
+  def run(_args) do
+    raise Mix.Error, message: "mix iex is deprecated. Due to the VM constraints, " <>
+      "IEx needs to be configured on boot. Use `iex -S mix` instead."
   end
 end

lib/mix/test/mix/cli_test.exs

@@ -14,7 +14,7 @@ defmodule Mix.CLITest do
     in_fixture "custom_mixfile", fn ->
       output = mix ""
       assert File.regular?("ebin/Elixir-A.beam")
-      assert output =~ %r"1 tests, 0 failures"
+      assert output =~ %r"Compiled lib/a.ex"
     end
   end
 

lib/mix/test/test_helper.exs

@@ -66,7 +66,7 @@ defmodule MixTest.Case do
   end
 
   def mix(args) do
-    System.cmd "#{mix_executable} #{args}"
+    System.cmd "#{elixir_executable} #{mix_executable} #{args}"
   end
 
   def mix_executable do