Rails - Model Associations - User and Product - Custom methods - ruby-on-rails

Question

I'm creating an app with two main models : User and Product. User can have many products as an owner, and many products as a borrower. Product have only one owner, but can have many seekers, including a borrower. I associated them directly for the owning property, but for the borrowing property, I created a Transaction model. The three look like this :
app/models/transaction.rb
class Transaction
# has a seeker_id:integer, a product_id:integer and a current:boolean
before_save :check_current
# Associations
belongs_to :seeker, class_name: "User", foreign_key: "seeker_id"
belongs_to :product
# Methods
def check_current
if !self.borrowing_date.nil? && self.return_date.nil?
self.current = true
end
end
end
A product has many transactions, but it can be borrowed by only one seeker at the time. When the product is borrowed, the transaction has a borrowing_date that is not nil, and a return_date that is nil. Then the check_current method toggles the current boolean of this transaction from false to true. The seeker of that current transaction is specified as a borrower.
app/models/user.rb
class User
.
.
.
has_many :owned_products, class_name: "Product", foreign_key: "owner_id", dependent: :destroy
has_many :transactions, foreign_key: "seeker_id", dependend: :destroy
has_many :requested_products, through: :transactions, source: :product
has_many :active_transactions, -> { where current: true },
class_name: 'Transaction',
foreign_key: "seeker_id",
dependent: :destroy
has_many :borrowed_products, through: :active_transactions,
source: :product
def requesting?(product)
self.transactions.find_by(product_id: product.id)
end
def request!(product)
self.transactions.create!(product_id: product.id)
end
def borrowing?(product)
self.transactions.find_by(product_id: product.id, current: true)
end
def borrowed_products
self.transactions.where(current: :true).product
end
end
app/models/products.rb
class Product
.
.
.
belongs_to :owner, class_name: "User", foreign_key: "owner_id"
has_many :transactions, dependent: :destroy
has_many :seekers, through: :transactions,
source: :seeker
def borrowed?
self.transactions.find_by(current: true)
end
def borrower
self.transactions.find_by(current: true).seeker
end
end
When I testing some of my code, five of the tests fail, the same type, and I don't understand why :
describe User do
before { #user = User.new(name: "Utilisateur de test",
email: "test#utilisateur.com",
password: "motdepasse",
password_confirmation: "motdepasse") }
subject { #user }
describe "requested product associations" do
let(:lender) { FactoryGirl.create(:user) }
let(:product) { FactoryGirl.create(:product, owner: lender) }
before do
#user.save
#user.request!(product)
end
it { should be_requesting(product) }
its(:requested_products) { should include(product) } # FAIL
describe "when product is borrowed" do
before do
transaction = Transaction.find_by(product: product)
transaction.update_attributes(borrowing_date: 1.day.ago)
transaction.save
end
it { should be_borrowing(product) }
its(:requested_products) { should_not include(product) } # FAIL
its(:borrowed_products) { should include(product) } # FAIL
describe "then returned" do
before do
transaction = Transaction.find_by(product: product)
transaction.update_attributes(return_date: 1.hour.ago)
end
it { should_not be_borrowing(product) }
its(:requested_products) { should_not include(product) } # FAIL
its(:borrowed_products) { should_not include(product) } # FAIL
end
end
end
end
Here are the error messages :
1) User requested product associations requested_products
Failure/Error: its(:requested_products) { should include(product) }
ActiveRecord::StatementInvalid:
SQLite3::SQLException: ambiguous column name: created_at: SELECT 1 AS one FROM "products" INNER JOIN "transactions" ON "products"."id" = "transactions"."product_id" WHERE "transactions"."seeker_id" = ? AND "products"."id" = 1 ORDER BY created_at DESC LIMIT 1
# ./spec/models/user_spec.rb:174:in `block (3 levels) in <top (required)>'
2) User requested product associations when product has been borrowed borrowed_products
Failure/Error: its(:borrowed_products) { should include(product) }
ActiveRecord::StatementInvalid:
SQLite3::SQLException: ambiguous column name: created_at: SELECT 1 AS one FROM "products" INNER JOIN "transactions" ON "products"."id" = "transactions"."product_id" WHERE "transactions"."seeker_id" = ? AND "transactions"."current" = 't' AND "products"."id" = 1 ORDER BY created_at DESC LIMIT 1
# ./spec/models/user_spec.rb:185:in `block (4 levels) in <top (required)>'
3) User requested product associations when product has been borrowed requested_products
Failure/Error: its(:requested_products) { should_not include(product) }
ActiveRecord::StatementInvalid:
SQLite3::SQLException: ambiguous column name: created_at: SELECT 1 AS one FROM "products" INNER JOIN "transactions" ON "products"."id" = "transactions"."product_id" WHERE "transactions"."seeker_id" = ? AND "products"."id" = 1 ORDER BY created_at DESC LIMIT 1
# ./spec/models/user_spec.rb:184:in `block (4 levels) in <top (required)>'
4) User requested product associations when product has been borrowed then returned requested_products
Failure/Error: its(:requested_products) { should_not include(product) }
ActiveRecord::StatementInvalid:
SQLite3::SQLException: ambiguous column name: created_at: SELECT 1 AS one FROM "products" INNER JOIN "transactions" ON "products"."id" = "transactions"."product_id" WHERE "transactions"."seeker_id" = ? AND "products"."id" = 1 ORDER BY created_at DESC LIMIT 1
# ./spec/models/user_spec.rb:195:in `block (5 levels) in <top (required)>'
5) User requested product associations when product has been borrowed then returned borrowed_products
Failure/Error: its(:borrowed_products) { should_not include(product) }
ActiveRecord::StatementInvalid:
SQLite3::SQLException: ambiguous column name: created_at: SELECT 1 AS one FROM "products" INNER JOIN "transactions" ON "products"."id" = "transactions"."product_id" WHERE "transactions"."seeker_id" = ? AND "transactions"."current" = 't' AND "products"."id" = 1 ORDER BY created_at DESC LIMIT 1
# ./spec/models/user_spec.rb:196:in `block (5 levels) in <top (required)>'
But when I run some tests manually in the rails console, the user.borrowed_products and user.requested_products work just fine. Weird ???

Answer 1

For the first failing test
def borrowed_products
self.transactions.where(current: :true).product
end
The above method checks for current: true. I don't see you setting the attribute in your transaction setup.
before do
transaction = Transaction.find_by(product: product)
transaction.update_attributes(borrowing_date: 1.day.ago) #Why are you setting borrowing date. How is borrowing date and current related?
transaction.save
end
For the Second test.
requested_products association is established through transactions. You are not setting up a transaction. Is it done in your factory?

Answer 2

OK I found ! Yippee-ki-yay !
The error messages were telling me the created_at column was ambiguous. But why ? Because there are as much created_at column as there are associated models ! So it had something to do with it. But where the created_at appeared in my code ?
I checked my app/models/transaction.rb, my app/models/user.rb and my app/models/product.rb, and in this last model, I found the line :
default_scope -> { order('created_at DESC') }
That I changed to that, just to try :
default_scope -> { order('name DESC') }
And everything went just fine !
But now, if I want to scope it by created_at, I don't know how to do it :-p