controller_macros.rb

module ControllerMacros
  [:get, :post, :put, :delete].each do |method|
    class_eval <<-RUBY
      def on_#{method}(action, options = {}, &block)
        on_http_method(#{method.inspect}, action, options, &block)
      end
    RUBY
  end

  def on_http_method(method, action, options = {}, &block)
    description = "on #{method.to_s.upcase} to #{action.inspect}"
    if options.is_a?(Hash)
      options.each do |key, value|
        description << " with #{key}=#{value.inspect}"
      end
    end
    context description do
      setup do
        opts = convert_hash_values_to_instance_variable_params(options)
        send(method, action, opts)
      end
      merge_block(&block)
    end
  end
end

module ControllerHelpers
  def convert_hash_values_to_instance_variable_params(hash)
    converted = {}
    hash.each do |k, v|
      if v.is_a?(Hash)
        v = convert_hash_values_to_instance_variable_params(v)
      elsif v.to_s.starts_with?("@")
        v = instance_eval(v.to_s)
      end
      converted[k] = v
    end
    converted
  end
end

class Test::Unit::TestCase
  extend ControllerMacros
  include ControllerHelpers
end

projects_controller_test.rb

require 'test_helper'

class ProjectsControllerTest < ActionController::TestCase
  on_get :index do
    should_respond_with :success
    should_assign_to :projects
  end

  on_get :index, :format => "xml" do
    should_respond_with :success
    should_assign_to :projects
  end

  on_get :new do
    should_respond_with :success
  end

  context "Given a client" do
    setup do
      @client = Factory.create(:client)
    end

    on_post :create, :project => Factory.attributes_for(:project, :client_id => "@client") do
      should_change "Project.count", :by => 1
      should_redirect_to "project_path(@project)"
    end
  end

  context "Accessing a project" do
    setup do
      @project = Factory.create(:project)
    end

    on_get :show, :id => "@project" do
      should_respond_with :success
    end

    on_get :edit, :id => "@project.to_param" do
      should_respond_with :success
    end

    on_put :update, :id => :@project, :project => {} do
      should_redirect_to "project_path(@project)"
    end

    on_delete :destroy, :id => "@project" do
      should_change "Project.count", :by => -1
      should_redirect_to "projects_path"
    end
  end
end