Rspec Usage (Lambda, Expect)

lambda_expect.rb

# 1 - Lambda

lambda {
  post :create, :document => FactoryGirl.attributes_for(:document)
}.should change { Document.count }.by(1)

# 2 - Expect

expect {
  post :create, :document => FactoryGirl.attributes_for(:document)
}.should change { Document.count }.by(1)

# 3 - In latest RSpec

expect {
  post :create, :document => FactoryGirl.attributes_for(:document)
}.to change(Document, :count).by(1)