cask: use Tempfile and some style fixes

Library/Homebrew/cask/lib/hbc/artifact/pkg.rb

@@ -55,19 +55,16 @@ module Hbc
         args << "-verboseR" if Hbc.verbose
         args << "-allowUntrusted" if pkg_install_opts :allow_untrusted
         if pkg_install_opts :choices
-          args << "-applyChoiceChangesXML"
-          args << choices_xml
+          choices_file = choices_xml
+          args << "-applyChoiceChangesXML" << choices_file.path
         end
         @command.run!("/usr/sbin/installer", sudo: true, args: args, print_stdout: true)
       end
 
       def choices_xml
-        path = @cask.staged_path.join("Choices.xml")
-        unless File.exist? path
-          choices = pkg_install_opts :choices
-          IO.write path, Plist::Emit.dump(choices)
-        end
-        path
+        file = Tempfile.open(["", ".xml"])
+        file.write Plist::Emit.dump(pkg_install_opts(:choices))
+        file
       end
     end
   end

Library/Homebrew/cask/test/cask/artifact/pkg_test.rb

@@ -40,31 +40,32 @@ describe Hbc::Artifact::Pkg do
     end
 
     it "passes the choice changes xml to the system installer" do
-      pkg = Hbc::Artifact::Pkg.new(@cask,
-                                   command: Hbc::FakeSystemCommand)
-
-      Hbc::FakeSystemCommand.expects_command(["/usr/bin/sudo", "-E", "--", "/usr/sbin/installer", "-pkg", @cask.staged_path.join("MyFancyPkg", "Fancy.pkg"), "-target", "/", "-applyChoiceChangesXML", @cask.staged_path.join("Choices.xml")])
+      pkg = Hbc::Artifact::Pkg.new(@cask, command: Hbc::FakeSystemCommand)
 
-      shutup do
-        pkg.install_phase
-      end
-
-      IO.read(@cask.staged_path.join("Choices.xml")).must_equal <<-EOS.undent
+      file = mock
+      file.expects(:write).with <<-EOS.undent
         <?xml version="1.0" encoding="UTF-8"?>
         <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
         <plist version="1.0">
         <array>
-        	<dict>
-        		<key>attributeSetting</key>
-        		<integer>1</integer>
-        		<key>choiceAttribute</key>
-        		<string>selected</string>
-        		<key>choiceIdentifier</key>
-        		<string>choice1</string>
-        	</dict>
+        \t<dict>
+        \t\t<key>attributeSetting</key>
+        \t\t<integer>1</integer>
+        \t\t<key>choiceAttribute</key>
+        \t\t<string>selected</string>
+        \t\t<key>choiceIdentifier</key>
+        \t\t<string>choice1</string>
+        \t</dict>
         </array>
         </plist>
       EOS
+      file.stubs path: Pathname.new("/tmp/choices.xml")
+      Tempfile.expects(:open).returns(file)
+      Hbc::FakeSystemCommand.expects_command(["/usr/bin/sudo", "-E", "--", "/usr/sbin/installer", "-pkg", @cask.staged_path.join("MyFancyPkg", "Fancy.pkg"), "-target", "/", "-applyChoiceChangesXML", @cask.staged_path.join("/tmp/choices.xml")])
+
+      shutup do
+        pkg.install_phase
+      end
     end
   end
 end