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Asked: 2020-12-08 12:59:30 +0800 CST 2020-12-08 12:59:30 +0800 CST

Uniqueness validation not working Rails

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I am trying to prove that a foreign key is unique, since only one relationship can exist on that table per user.

My doubt is that I don't know if I have to put a restriction on the table indicating that the foreign field is also unique, or just placing the uniqueness validation in the ActiveRecord works.

My ActiveRecord:

class Balance < ActiveRecord::Base
  #association macros
  belongs_to :user
  belongs_to :wallet

  #validation macros
  validates :user_id, presence: true, uniqueness: true
  validates :wallet_id, presence: true
end

My Factory:

FactoryGirl.define do
  factory :balance do
    user
    wallet
    amount 2000
  end
end

My quiz:

RSpec.describe Balance, type: :model do

  let(:balance) { FactoryGirl.create :balance }

  it "when is valid" do
    expect(balance).to be_valid
  end

  it "when is presence user_id" do
    expect(balance).to validate_presence_of :user_id
  end

  it "when is presence wallet_id" do
    expect(balance).to validate_presence_of :wallet_id
  end

  it "when is uniqueness user_id" do
    expect(balance).to validate_uniqueness_of :user_id #falla
  end


  it "when is belongs_to :user" do
    should belong_to(:user)
  end

  it "when is belongs_to :wallet" do
    should belong_to(:wallet)
  end

end

Mistake

Balance when is uniqueness user_id
     Failure/Error: let(:balance) { FactoryGirl.create :balance }
     ActiveRecord::RecordInvalid:
       Validation failed: User has already been taken
     # ./spec/models/balance_spec.rb:5:in `block (2 levels) in <top (required)>'
     # ./spec/models/balance_spec.rb:20:in `block (2 levels) in <top (required)>
ruby-on-rails

1 Answers

  1. Best Answer

    My doubt is that I don't know if I have to put a restriction on the table indicating that the foreign field is also unique, or just placing the uniqueness validation in the ActiveRecord works.

    It is not necessary (although recommended) to put restrictions on the database.

    The bug is in the test that fails when trying to create an extra instance of Balance(and finds that you already created one before).

    Grades

    It would be nice if you shortened the code blocks a bit, so that the questions are more concise.

    In these cases it is important to comment on the libraries you are using, in this case the error is in the use of shoulda which is not mentioned in the question.

    Testing this type of detail is usually not necessary and even counterproductive, Rails has its own tests, it is not necessary to retest it.

    Lastly, if you insist on testing this, it is convenient to persist the instances in the database ( FactoryGirl.create) while it is enough to use FactoryGirl.buildwhich is much faster.

    Update

    Shoulda doesn't work well when the uniqueness validation is on a foreing_key, because it tries to assign 'a' to it as a value .

    If you still want to do the test, you can do it by hand:

    it 'validates uniqueness on user_id' do
  balance # creo la instancia del let
  dup_balance = balance.dup
  dup_balance.user = balance.user
  expect(dup_balance).not_to be_valid
end

    Likewise, doing this type of test is not recommended.

    • 4