class MiniPortile

def apply_patch(patch_file)
  (
    # Not a class variable because closures will capture self.
    @apply_patch ||=
    case
    when which('git')
      lambda { |file|
        message "Running git apply with #{file}... "
        Dir.mktmpdir do |tmp_git_dir|
          execute('patch', ["git", "--git-dir=#{tmp_git_dir}", "--work-tree=.", "apply", "--whitespace=warn", file], :initial_message => false)
        end
      }
    when which('patch')
      lambda { |file|
        message "Running patch with #{file}... "
        execute('patch', ["patch", "-p1", "-i", file], :initial_message => false)
      }
    else
      raise "Failed to complete patch task; patch(1) or git(1) is required."
    end
  ).call(patch_file)
end