Add RSpec based specs.

Because:
We encountered lately too much 💥 that could be avoided.

This commit:
Is a starting point for testing the gem.
The first thing tested here is the generator, ensuring it creates or
updates the expected files.

Rakefile

@@ -1 +1,8 @@
-require "bundler/gem_tasks"
+require 'bundler/setup'
+require 'bundler/gem_tasks'
+require 'rspec/core/rake_task'
+
+RSpec::Core::RakeTask.new(:rspec)
+
+desc 'Run the test suite'
+task :default => :rspec

foundation-rails.gemspec

@@ -18,8 +18,12 @@ Gem::Specification.new do |spec|
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ["lib"]
 
-  spec.add_development_dependency "bundler", "~> 1.3"
   spec.add_dependency "sass", [">= 3.3.0", "< 3.5"]
   spec.add_dependency "railties", [">= 3.1.0"]
+
+  spec.add_development_dependency "bundler", "~> 1.3"
+  spec.add_development_dependency "capybara"
   spec.add_development_dependency "rake"
+  spec.add_development_dependency "rails"
+  spec.add_development_dependency "rspec", "~> 3.2"
 end

spec/features/generator_spec.rb

@@ -0,0 +1,25 @@
+require 'spec_helper'
+
+feature 'Foundation install succeeds' do
+  scenario 'stylesheets assets files are added' do
+    application_css_file = IO.read("#{dummy_app_path}/app/assets/stylesheets/application.css")
+
+    expect(File).to exist("#{dummy_app_path}/app/assets/stylesheets/foundation_and_overrides.scss")
+    expect(application_css_file).to match(/require foundation_and_overrides/)
+  end
+
+  scenario 'javascripts assets files are added' do
+    application_js_file = IO.read("#{dummy_app_path}/app/assets/javascripts/application.js")
+
+    expect(application_js_file).to match(/require foundation/)
+    expect(application_js_file).to match(Regexp.new(Regexp.escape('$(function(){ $(document).foundation(); });')))
+  end
+
+  scenario 'layout file loads assets' do
+    layout_file = IO.read("#{dummy_app_path}/app/views/layouts/application.html.erb")
+
+    expect(layout_file).to match(/stylesheet_link_tag    "application"/)
+    expect(layout_file).to match(/javascript_include_tag "vendor\/modernizr"/)
+    expect(layout_file).to match(/javascript_include_tag "application/)
+  end
+end

spec/spec_helper.rb

@@ -0,0 +1,19 @@
+require 'capybara/rspec'
+require 'bundler/setup'
+
+Bundler.require(:default, :test)
+
+Dir['./spec/support/**/*.rb'].each { |file| require file }
+
+RSpec.configure do |config|
+  config.include FoundationRailsTestHelpers
+
+  config.before(:all) do
+    create_dummy_app
+    install_foundation
+  end
+
+  config.after(:all) do
+    remove_dummy_app
+  end
+end

spec/support/helpers.rb

@@ -0,0 +1,25 @@
+module FoundationRailsTestHelpers
+  def create_dummy_app
+    FileUtils.cd(tmp_path) do
+      %x(rails new dummy --skip-active-record --skip-test-unit --skip-spring)
+    end
+  end
+
+  def remove_dummy_app
+    FileUtils.rm_rf(dummy_app_path)
+  end
+
+  def install_foundation
+    FileUtils.cd(dummy_app_path) do
+      %x(rails g foundation:install -f 2>&1)
+    end
+  end
+
+  def dummy_app_path
+    File.join(tmp_path, 'dummy')
+  end
+
+  def tmp_path
+    @tmp_path ||= File.join(File.dirname(__FILE__), '..')
+  end
+end