Rails - Test validation of enum fields

Question

I'm using Rails 4 enums and I want to properly test them, so I set these tests up for my enum fields:

it { should validate_inclusion_of(:category).in_array(%w[sale sale_with_tax fees lease tax_free other payroll]) }
it { should validate_inclusion_of(:type).in_array(%w[receivable payable]) }

And this is the model they're validating:

class Invoice < ActiveRecord::Base
  belongs_to :user

  enum category: [:sale, :sale_with_tax, :fees, :lease, :tax_free, :other, :payroll]
  enum type: [:receivable, :payable]

  validates :user, presence: true
  validates :issue_date, presence: true
  validates :series, presence: true
  validates :folio, presence: true
  validates :issuing_location, presence: true
  validates :payment_method, presence: true
  validates :last_digits, presence: true
  validates :credit_note, presence: true
  validates :total, presence: true
  validates :subtotal, presence: true
  validates :category, presence: true
  validates_inclusion_of :category, in: Invoice.categories.keys
  validates :type, presence: true
  validates_inclusion_of :type, in: Invoice.types.keys
end

But when I run the tests I get:

1) Invoice should ensure inclusion of type in [0, 1]
     Failure/Error: it { should validate_inclusion_of(:type).in_array([0,1]) }
     ArgumentError:
       '123456789' is not a valid type
     # ./spec/models/invoice_spec.rb:20:in `block (2 levels) in <top (required)>'

  2) Invoice should ensure inclusion of category in [0, 1, 2, 3, 4, 5, 6]
     Failure/Error: it { should validate_inclusion_of(:category).in_array([0,1,2,3,4,5,6]) }
     ArgumentError:
       '123456789' is not a valid category
     # ./spec/models/invoice_spec.rb:19:in `block (2 levels) in <top (required)>'

I've also tried with string values in the test arrays, but I get the same error and I really don't understand it.

Answer 1

Using Shoulda matchers we can use the following to test the enum

it { should define_enum_for(:type).with([:receivable, :payable]) }

it { should define_enum_for(:category).
            with(:sale, :sale_with_tax, :fees, :lease, :tax_free, :other, :payroll) }

Answer 2

Try this:

it { should validate_inclusion_of(:category).in_array(%w[sale sale_with_tax fees lease tax_free other payroll].map(&:to_sym)) }

Additionally, for code-cleanup, try putting the valid categories/types in a corresponding constant. Example:

class Invoice < ActiveRecord::Base
  INVOICE_CATEGORIES = [:sale, :sale_with_tax, :fees, :lease, :tax_free, :other, :payroll]
  enum category: INVOICE_CATEGORIES
end

Answer 3

Your migration could be the issue, it should look something like:

t.integer :type, default: 1

You may also consider testing this another way.

Maybe more like:

it "validates the category" do
  expect(invoice with category fee).to be_valid
end