# frozen_string_literal: true require_relative 'helper' describe Rack::Config do it "accept a block that modifies the environment" do app = Rack::Builder.new do use Rack::Lint use Rack::Config do |env| env['greeting'] = 'hello' end run lambda { |env| [200, { 'Content-Type' => 'text/plain' }, [env['greeting'] || '']] } end response = Rack::MockRequest.new(app).get('/') response.body.must_equal 'hello' end end