ruby on rails - Testing a simple has many association through a join table -

to wrap exercise i'm working on, i'm trying test association through join table. i'd test association artists have many collections through art pieces , collections have many artists through art pieces. below code:

context 'associations'  let(:artist){ artist.create(first_name: "daniel", last_name: "rubio",                email: 'drubs@email.com', birthplace: 'mexico',                style: 'contemporary') }  let(:art_piece) { artpiece.new(date_of_creation: datetime.parse('2012-3-13'),                       placement_date_of_sale: datetime.parse('2014-8-13'),                    cost: 250, medium: 'sculpture', availability: true, artist_id:                    artist.id, customer_id: customer.id,                    collection_id: collection.id)}  let(:customer) { customer.create(first_name: 'carmen', last_name: 'dent', email:                   'cdent@email.com', no_of_purchases: 10, amount_spent: 100000) }  let(:collection) { collection.create(name: 'romanticism') }  'has many collections through art pieces'   expect(artist).to respond_to(:collections)   art_piece.save!   expect(artist.collections).to eql(collection) end  end  

now i'm positive associations setup correctly on validations:

class collection < activerecord::base   validates_presence_of :name    has_many :art_pieces   has_many :artists, through: :art_pieces end  class artist < activerecord::base   validates_presence_of :first_name   validates_presence_of :last_name   validates :email, presence: true, uniqueness: true   validates_presence_of :style   validates_presence_of :birthplace    has_many :art_pieces   has_many :collections, through: :art_pieces end 

i followed activerecord's guidelines , makes sense me. 2 things think happening either a. have syntax error somewhere or b. variables not being chained properly. insight?

below error message get:

1) artist associations has many collections through art pieces  failure/error: expect(artist.collections).to eql(collection)     expected: #<collection id: 20, name: "romanticism", created_at: "2014-04-06 16:57:42", updated_at: "2014-04-06 16:57:42">         got: #<activerecord::associations::collectionproxy [#<collection id: 20, name: "romanticism", created_at: "2014-04-06 16:57:42", updated_at: "2014-04-06 16:57:42">]>     (compared using eql?)     diff:    @@ -1,2 +1,2 @@    -#<collection id: 20, name: "romanticism", created_at: "2014-04-06 16:57:42", updated_at: "2014-04-06 16:57:42">    +[#<collection id: 20, name: "romanticism", created_at: "2014-04-06 16:57:42", updated_at: "2014-04-06 16:57:42">] 

artist.collection returns array-like relation, while test return single activerecord object. should have:

expect(artist.collections).to eql([collection]) 

in test.