Question

I’m looking to write a test that can validate the uniqueness of a compound validation (if that makes sense). The validation itself is as follows:

validates_uniqueness_of :name, :scope => [:address_postcode]

How do I do that? Would I simply try and create two places with the same name and try to validate? For example (and this code doesn’t work)

test "name and postcode of a new place must be unique" do
  place = Place.new(description: "my favourite chinese", cuisine:"chinese", 
    address_state:"NSW", address_country:"Australia", address_postcode:"2209")
  place.name = "Masthai"
  assert place.valid?

  place2 = Place.new(description: "try a second restaurant", cuisine:"chinese", 
    address_state:"NSW", address_country:"Australia", address_postcode:"2209")
  place2.name = "Masthai"
  assert place2.invalid?
end

Answer 1

place2 is probably valid because you’re not saving place to the database. I would try this:

test "name and postcode of a new place must be unique" do
  place = Place.create(description: "my favourite chinese", cuisine:"chinese", 
    address_state:"NSW", address_country:"Australia", address_postcode:"2209")
  place.name = "Masthai"
  assert place.valid?

  place2 = Place.new(description: "try a second restaurant", cuisine:"chinese", 
    address_state:"NSW", address_country:"Australia", address_postcode:"2209")
  place2.name = "Masthai"
  assert place2.invalid?
end

Also, I’d like to offer a suggestion on formatting/style:

test "name and postcode of a new place must be unique" do
  place = Place.create(
    description: "my favourite chinese",
    cuisine: "chinese", 
    address_state: "NSW",
    address_country: "Australia",
    address_postcode: "2209",
    name: "Masthai"
  )
  assert place.valid?

  place2 = Place.new(
    description: "try a second restaurant",
    cuisine: "chinese", 
    address_state: "NSW",
    address_country: "Australia",
    address_postcode: "2209",
    name: "Masthai"
  )
  assert place2.invalid?
end

Also, I’d recommend that you read a little bit about database normalization. You should really have separate tables for cuisine, state and country, rather than storing these values as freeform text.