试图了解为什么validates_presence_of测试失败

Question

I'm just starting to have a play with Rails (using Rspec and Shoulda Matchers) to build a demo blog.

I've literally just started and my first test is failing but I can't understand why.

I think I've set up everything correctly, but when I try to validate that a title is present on my Article model but it returns a failure

Shoulda::Matchers::ActiveModel::AllowValueMatcher::AttributeDoesNotExistError:
   The matcher attempted to set :title on the Article to nil, but that
   attribute does not exist.

My model looks like this...

class Article < ApplicationRecord
  # attr_accessor :title
  validates_presence_of :title
end

and my test...

require 'rails_helper'

RSpec.describe Article do
  it { should validate_presence_of :title }
end

If I uncomment out the attr_accessor then the test passes but I understand that it's not required with Rails.

What am I doing wrong?

Answer 1

The attr_accessor is not required, as long as your articles database table has a title column.

You can check that in db/schema.rb .