Project: RSpec Core 2.1

Publisher: RSpec

attribute of subject

Use the its() method as a short-hand to generate a nested example group with
a single example that specifies the expected value of an attribute of the subject.
This can be used with an implicit or explicit subject.

its() accepts a symbol or a string, and a block representing the example. Use
a string with dots to specify a nested attribute (i.e. an attribute of the
attribute of the subject).

Scenarios

simple attribute

Given

a file named "example_spec.rb" with:

describe Array do
  its(:size) { should == 0 }
end

When

I run "rspec example_spec.rb --format documentation"

Then

the output should contain:

Array
  size
    should == 0

nested attribute

Given

a file named "example_spec.rb" with:

class Person
  attr_reader :phone_numbers
  def initialize
    @phone_numbers = []
  end
end

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

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

When

I run "rspec example_spec.rb --format documentation"

Then

the output should contain:

Person
  phone_numbers.first
    should == "555-1212"

Last published about 7 years ago by dchelimsky.

attribute of subject

RSpec Core settings