# File lib/spring/test/application_generator.rb, line 86
      def install_spring
        return if @installed

        if RUBY_VERSION < "2.2.2"
          application.run! "gem install activesupport --version '#{version}'"
        end

        build_and_install_gems

        # TO prevent nokogiri install error in application.bundle.
        if RUBY_VERSION < "2.1.0"
          append_to_file(application.gemfile, "gem 'nokogiri', '~> 1.6.8'")
        end

        application.bundle

        FileUtils.rm_rf application.path("bin")

        if application.path("bin_original").exist?
          FileUtils.cp_r application.path("bin_original"), application.path("bin")
        end

        application.run! "#{application.spring} binstub --all"
        @installed = true
      end