Rails MiniTestでlibとhelperテストのメモ ref: http://qiita.com/t_oginogin/items/7654190749dc6fcce732

application_helper_test.rb

require "test_helper"

describe ApplicationHelper do
  before do
    class TestHelper < ActionView::Base
      include ApplicationHelper
    end
    @helper = TestHelper.new
  end

  describe "sampleを実行" do
    it "Sampleが返却される" do
      assert_equal 'Sample', @helper.sample
    end
  end
end

Rakefile

:
MiniTest::Rails::Testing.default_tasks << 'lib'
:

xxx_test.rb

require "test_helper"

describe SampleLib do
  before do
    class TestSampleLib
      include SampleLib
    end
    @loader = TestSampleLib.new
  end

  describe "sampleを実行" do
    it "Sampleが返却される" do
      assert_equal 'Sample' @loader.sample
    end
  end
end