Module: RSpec::Core::Subject::ExampleGroupMethods

Included in:
ExampleGroup
Defined in:
lib/rspec/core/subject.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#explicit_subject_blockObject (readonly)

Returns the value of attribute explicit_subject_block


155
156
157
# File 'lib/rspec/core/subject.rb', line 155

def explicit_subject_block
  @explicit_subject_block
end

Instance Method Details

#its(attribute, &block) ⇒ Object

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

120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
# File 'lib/rspec/core/subject.rb', line 120

def its(attribute, &block)
  describe(attribute) do
    example do
      self.class.class_eval do
        define_method(:subject) do
          @_subject ||= if attribute.is_a?(Array)
                          super()[*attribute]
                        else
                          attribute.to_s.split('.').inject(super()) do |target, method|
                            target.send(method)
                          end
                        end
        end
      end
      instance_eval(&block)
    end
  end
end

#subject(&block) ⇒ Object

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

See ExampleMethods#should for more information about this approach.

Examples:


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

151
152
153
# File 'lib/rspec/core/subject.rb', line 151

def subject(&block)
  block ? @explicit_subject_block = block : explicit_subject || implicit_subject
end