cheatsheets/rspec.md

title	category
RSpec	Ruby

Invoking tests

rake -T spec      # List spec tasks

rake spec         # Run all

rake spec/models/mymodel_spec.rb
rake spec/models/mymodel_spec.rb:27

Spec helpers

module UserSpecHelper
  def valid_user_attributes
    { :email => "joe@bloggs.com",
      :username => "joebloggs",
      :password => "abcdefg"}
  end
end

A test

describe "A User (in general)" do
  include UserSpecHelper

  before(:each) do
    @user = User.new
  end

  subject {
    Person.new
  }

  context "setter methods" do
    it "should do this" do
      pending "some other thing"

      expect(subject.name).to eq 'x'
    end
  end
end

Expectations

target.should eq 1
target.should_not eq 1
expect(target).to eq 1
expect(target).not_to eq 1

# Numeric
be < 6
== 5
equal value
be_between(1, 10)
be_within(0.05).of value

be value
satisfy {|arg| ...}
predicate [optional args]
match regexp

be_an_instance_of <class>
be_a_kind_of <class>

respond_to <symbol>

# Control flow
raise_error
raise_error(<exception> [, message])

throw <symbol>

# Enumerables/arrays
include <object>

have(<number>).things
have_at_least(<number>).things
have_at_most(<number>).things

have(<number>).errors_on(:field)

# Change
change(instance, method).from(number).to(number)

# proc.should <=> expect(&proc).to
expect { thing.approve! }.to change(thing, :status).
    from(Status::AWAITING_APPROVAL).
    to(Status::APPROVED)

expect { thing.destroy }.to change(Thing, :count).by(-1)

Double

book = double('book')
book = instance_double('Book', pages: 250)

Method stubs

allow(die).to receive(:roll)
allow(die).to receive(:roll) { 3 }

expect(die).to receive(:roll)
  .with(1)
  .with(1, true)
  .with(boolean)
  .with(anything)
  .with(any_args)
  .with(1, any_args)
  .with(no_args)
  .with(hash_including(a: 1))
  .with(hash_excluding(a: 1))
  .with(array_including(:a, :b))
  .with(array_excluding(:a, :b))
  .with(instance_of(Fixnum))
  .with(kind_of(Numeric))
  .with(<matcher>)


  .once
  .twice
  .exactly(n).times
  .at_least(:once)
  .at_least(:twice)
  .at_least(n).times
  .at_most(:once)
  .at_most(:twice)
  .at_most(n).times

https://relishapp.com/rspec/rspec-mocks/docs

Subjects

describe CheckingAccount, "with a non-zero balance" do
  subject(:account) { CheckingAccount.new }
  it { is_expected.not_to be_overdrawn }
end