Po co należy testować?

Testy behawioralne?

Testowanie zachowania (skutków) klas a nie ich stanu.

Krok pierwszy

$ gem install rspec
...
5 gems installed

Krok drugi

$ rspec --init
  create   spec/spec_helper.rb
  create   .rspec

describe

podstawowy blok Rspec

require 'spec_helper'
describe "our Product" do
  # test-cases here
end

it

blok: konkretna testowana sytuacja

describe "our Product" do
  it "has a nonzero price"
end

describe klasy

describe Product do
  it "has a nonzero price"
end

it + blok

i nasza pierwsza "asercja"

describe Product do
  it "has a default price" do
    product = Product.new
    product.price.should == 10
  end
end

predykaty

available? => should be_available

describe Product do
  it "is available by default" do
    product = Product.new
    product.available.should == true
    product.available.should be_true
    product.should be_available
  end
end

pending

"oczekuje na implementację"

describe Product do
  it "has many variants"
  it "belongs to category" do
    pending
    product.category should_not be_nil
  end
  xit "has weight" do
    product.weight should_not be_nil
  end
end

let

leniwe wykonanie:

wykonaj blok dopiero kiedy potrzebny

describe Product do
  let(:product) { Product.new }
  it "has a default price" do
    product.price.should == 10
  end
end

describe describe describe

zagnieżdżanie kontekstów

describe Product do
  describe "showing let in action" do
    let(:product) { Product.new }
    describe "describe can be nested" do
      let(:products) {[product, product]}
      it "has a default price" do
        products[0].price.should == 10
      end
    end
  end
end

RSpec z Railsami

gem 'rspec-rails'

pamiętacie predykaty?

require 'spec_helper'
describe Product do
  it "is invalid without a name" do
    product = Product.new
    product.should_not be_valid
  end
end