RSpec undefined method "errors_on" - ruby-on-rails

Question

I have the following model that I want to test with RSpec:
class Language < ActiveRecord::Base
has_and_belongs_to_many :dvds
validates :title, presence: true, uniqueness: { case_sensitive: false }
end
language_spec.rb
describe Language do
describe 'title validation' do
context 'title is present' do
before(:each) do
#lang = Language.new(title: 'English')
end
it 'is valid with present title' do
expect(#lang).to have_exactly(0).errors_on(:title)
end
end
context 'title is not present' do
before(:each) do
#lang = Language.create
end
it 'has an error on title attribute' do
expect(#lang).to have_exactly(1).errors_on(:title)
end
end
end
end
Unfortunately I'm getting test failures:
Failures:
1) Language title validation title is present is valid with present
title
Failure/Error: expect(#lang).to have_exactly(0).errors_on(:title)
NoMethodError:
undefined method errors_on' for #<Language:0xaa40e98>
# ./spec/models/language_spec.rb:9:inblock (4 levels) in '
2) Language title validation title is not present has an error on
title attribute
Failure/Error: expect(#lang).to have_exactly(1).errors_on(:title)
NoMethodError:
undefined method errors_on' for #<Language id: nil, title: nil, created_at: nil, updated_at: nil>
# ./spec/models/language_spec.rb:19:inblock (4 levels) in '
Gemfile
source 'https://rubygems.org'
# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '4.1.1'
# Use sqlite3 as the database for Active Record
gem 'sqlite3'
# Use SCSS for stylesheets
gem 'sass-rails', '~> 4.0.3'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# Use CoffeeScript for .js.coffee assets and views
gem 'coffee-rails', '~> 4.0.0'
# See https://github.com/sstephenson/execjs#readme for more supported runtimes
# gem 'therubyracer', platforms: :ruby
# Use jquery as the JavaScript library
gem 'jquery-rails'
# Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
gem 'turbolinks'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.0'
# bundle exec rake doc:rails generates the API under doc/api.
gem 'sdoc', '~> 0.4.0', group: :doc
# Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
gem 'spring', group: :development
# Pagination plugin
gem 'will_paginate', '~> 3.0'
# Testing
group :development, :test do
gem "rspec-rails", "~> 3.0.1"
gem "factory_girl_rails", "~> 4.4.1"
end
group :test do
gem "faker", "~> 1.3.0"
gem "capybara", "~> 2.3.0"
gem "database_cleaner", "~> 1.3.0"
gem "launchy", "~> 2.4.2"
gem "selenium-webdriver", "~> 2.42.0"
end
Any ideas why I'm getting undefined method "errors_on"?

Answer 1

The errors_on matcher moved to the rspec-collection_matchers gem, so adding that to your Gemfile would fix the error.
If you wanted to move away from non-core syntax, you could do
describe Language do
describe 'title validation' do
context 'title is present' do
before(:each) do
#lang = Language.new(title: 'English')
end
it 'is valid with present title' do
expect(#lang.errors[:title]).to be_empty
end
end
context 'title is not present' do
before(:each) do
#lang = Language.create
end
it 'has an error on title attribute' do
expect(#lang.errors.added?(:title, :blank)).to be_true
end
end
end
end
(have_exactly and related matchers have also moved to rspec-collection_matchers.)

Answer 2

Try to set type option:
describe Language, type: :model do
Or use infer_spec_type_from_file_location! (See here)
RSpec.configure do |config|
config.infer_spec_type_from_file_location!
end