Verify appdir after reading command line opts

Helps prevent default appdir from being created regardless of whether
the user configured it or not.

Closes #496

lib/cask.rb

@@ -47,8 +47,9 @@ class Cask
       ohai "We need to make Caskroom for the first time at #{caskroom}"
       ohai "We'll set permissions properly so we won't need sudo in the future"
       current_user = ENV['USER']
-      system "sudo mkdir -p #{caskroom}"
-      system "sudo chown -R #{current_user}:staff #{caskroom.parent}"
+      sudo = 'sudo' unless caskroom.parent.writable?
+      system "#{sudo} mkdir -p #{caskroom}"
+      system "#{sudo} chown -R #{current_user}:staff #{caskroom.parent}"
     end
     appdir.mkpath unless appdir.exist?
   end

lib/cask/cli.rb

@@ -15,9 +15,9 @@ class Cask::CLI
   end
 
   def self.process(arguments)
-    Cask.init
     command, *rest = *arguments
     rest = process_options(rest)
+    Cask.init
     lookup_command(command).run(*rest)
   end
 

test/cask/cli_test.rb

@@ -12,4 +12,36 @@ describe Cask::CLI do
       phinze-cask/adium
     ])
   end
+
+  describe "process" do
+    it "creates the appdir if it does not exist" do
+      Cask.appdir.rmdir
+      shutup {
+        Cask::CLI.process('list')
+      }
+      Cask.appdir.directory?.must_equal true
+    end
+
+    it "respects the env variable when choosing what appdir to create, not touching the default appdir" do
+      default_applications_dir = Cask.appdir
+      default_applications_dir.rmdir
+      custom_applications_dir = Pathname(Dir.mktmpdir('custom_app_dir'))
+      custom_applications_dir.rmdir
+
+      default_applications_dir.directory?.must_equal false
+      custom_applications_dir.directory?.must_equal false
+
+      begin
+        ENV['HOMEBREW_CASK_OPTS'] = "--appdir=#{custom_applications_dir}"
+        shutup {
+          Cask::CLI.process('list')
+        }
+      ensure
+        ENV.delete 'HOMEBREW_CASK_OPTS'
+      end
+
+      default_applications_dir.directory?.must_equal false
+      custom_applications_dir.directory?.must_equal true
+    end
+  end
 end

test/support/fake_appdir.rb

@@ -9,7 +9,7 @@ module FakeAppdirHooks
 
   def after_teardown
     super
-    @canned_appdir.rmtree
+    @canned_appdir.rmtree if @canned_appdir.exist?
   end
 end
 

test/test_helper.rb

@@ -73,6 +73,7 @@ require 'support/fake_fetcher'
 require 'support/fake_appdir'
 require 'support/fake_system_command'
 require 'support/cleanup'
+require 'tmpdir'
 
 # pretend like we installed the cask tap
 project_root = Pathname.new(File.expand_path("#{File.dirname(__FILE__)}/../"))