RSpec::CollectionMatchers lets you express expected outcomes on collections of an object in an example.
expect(account.shopping_cart).to have_exactly(3).itemsAdd this line to your application's Gemfile:
gem 'rspec-collection_matchers'
And then execute:
$ bundle
Or install it yourself as:
$ gem install rspec-collection_matchers
First of all, you need to require rspec-collection matchers. Add the following line to your spec_helper.rb:
require 'rspec/collection_matchers'Using rspec-collection_matchers you can match the number of items in a
collection directly, e.g.:
it 'matches number of items in a collection' do
expect([1,2,3]).to have_at_least(3).items
endYou can also match the number of items returned by a method on an object, e.g.:
class Cart
def initialize(*products)
@products = products
end
attr_reader :products
end
it 'matches number of items returned from a method' do
cart = Cart.new('product a', 'product b')
expect(cart).to have_at_most(2).products
endThe last line of the example expresses an expected outcome:
if cart.products.size <= 2 then the example passes, otherwise it fails with a message like:
expected at most 2 products, got 3
expect(collection).to have(n).items
expect(collection).to have_exactly(n).items
expect(collection).to have_at_most(n).items
expect(collection).to have_at_least(n).items
expect(collection).to have(:no).items