Testing Sinatra helpers (in isolation) that depend on the params hash being present

my_helpers.rb

# encoding: UTF-8

module MyHelpers
  def foo
    "#{params[:bar]}"
  end
end

my_helpers_spec.rb

# encoding: UTF-8

require_relative "spec_helper"
require_relative "../lib/my_helpers.rb"

class FakeApp
  attr_accessor :params
  include MyHelpers

  def initialize(params = {})
    @params = params
  end
end

describe MyHelpers do
  subject { FakeApp }

  describe "foo" do
    it "returns the bar param" do
      s(bar: 'baz').foo.must_equal 'baz'
    end
  end
end

spec_helper.rb

# encoding: UTF-8

require 'bundler'

Bundler.setup
Bundler.require

require 'minitest/pride'
require 'minitest/autorun'
require 'minitest/spec'
require 'rack/test'

class MiniTest::Spec
  include Rack::Test::Methods
end

def s(*args)
  subject.new(*args)
end