Module RSpec::Core::Subject::ExampleGroupMethods
In: lib/rspec/core/subject.rb

Methods

its   subject  

Attributes

explicit_subject_block  [R] 

Public Instance methods

Creates a nested example group named by the submitted attribute, and then generates an example using the submitted block.

  # This ...
  describe Array do
    its(:size) { should eq(0) }
  end

  # ... generates the same runtime structure as this:
  describe Array do
    describe "size" do
      it "should eq(0)" do
        subject.size.should eq(0)
      end
    end
  end

The attribute can be a Symbol or a String. Given a String with dots, the result is as though you concatenated that String onto the subject in an expression.

  describe Person do
    subject do
      Person.new.tap do |person|
        person.phone_numbers << "555-1212"
      end
    end

    its("phone_numbers.first") { should eq("555-1212") }
  end

When the subject is a Hash, you can refer to the Hash keys by specifying a Symbol or String in an array.

  describe "a configuration Hash" do
    subject do
      { :max_users => 3,
        'admin' => :all_permissions }
    end

    its([:max_users]) { should eq(3) }
    its(['admin']) { should eq(:all_permissions) }

    # You can still access to its regular methods this way:
    its(:keys) { should include(:max_users) }
    its(:count) { should eq(2) }
  end

Defines an explicit subject for an example group which can then be the implicit receiver (through delegation) of calls to should.

@example

  describe CheckingAccount, "with $50" do
    subject { CheckingAccount.new(:amount => 50, :currency => :USD) }
    it { should have_a_balance_of(50, :USD) }
    it { should_not be_overdrawn }
  end

See +ExampleMethods#should+ for more information about this approach.

[Validate]