Practical tips on how to improve your RSpec specs and test suites in general. Slides ware presented on Slovenian Ruby Meetup on March 2014.

1. Tips for better tests
Oto Brglez / March 2014
otobrglez.opalab.com

2. #1 Describing methods?
describe 'the authenticate method for User' do
describe 'if the user is an admin' do
describe '.authenticate' do
describe '#admin?' do

3. #2 Missing some context?
it 'has 200 status code if logged in' do
expect(response).to respond_with 200
end
it 'has 401 status code if not logged in' do
expect(response).to respond_with 401
end
context 'when logged in' do
it { should respond_with 200 }
end
context 'when logged out' do
it { should respond_with 401 }
end

4. #3 Descriptions...
it 'has 422 status code if an unexpected params will be added' do
context 'when not valid' do
it { should respond_with 422 }
end

5. #4 Who?
it { expect(assigns('message')).to match /it was born in Maribor/ }
it { expect(assigns('message').creator).to match /Ljubljana/ }
subject { assigns('message') }
it { should match /it was born in Ljubljana/ }

6. #5 Be lazy...
describe '#type_id' do
before { @resource = FactoryGirl.create :device }
before { @type = Type.find @resource.type_id }
it 'sets the type_id field' do
expect(@resource.type_id).to equal(@type.id)
end
end
describe '#type_id' do
let(:resource) { FactoryGirl.create :device }
let(:type) { Type.find resource.type_id }
it 'sets the type_id field' do
expect(resource.type_id).to equal(type.id)
end
end

7. #6 See this a lot?
user = User.create(
first_name: 'Oto',
last_name: 'Brglez',
country: 'Slovenia',
email: 'otobrglez@gmail.com' ,
active: true
)
user = FactoryGirl.create :user

8. #7 Can’t remember...
lambda { model.save! }.to raise_error Mongoid::Errors::DocumentNotFound
expect { model.save! }.to raise_error Mongoid::Errors::DocumentNotFound

9. #8 But it works just like...
describe 'GET /devices' do
let!(:resource ) { FactoryGirl .create :device, created_from : user.id }
let(:uri) { '/devices' }
context 'when shows all resources' do
let!( :not_owned ) { FactoryGirl .create factory }
it 'shows all owned resources' do
page.driver.get uri
expect(page.status_code).to be( 200)
contains_owned_resource resource
does_not_contain_resource not_owned
end
end
describe '?start=:uri' do
it 'shows the next page' do
page.driver.get uri, start : resource.uri
expect(page.status_code).to be( 200)
contains_resource resources.first
expect(page).to_not have_content resource.id.to_s
end
end
end
describe 'GET /devices' do
let!(:resource) { FactoryGirl.create :device }
let(:uri) { '/devices' }
it_behaves_like 'a listable resource'
it_behaves_like 'a paginable resource'
it_behaves_like 'a searchable resource'
it_behaves_like 'a filterable list'
end

10. #9 Me, you, him? When?
it 'should not change timings' do
consumption.occur_at.should == valid.occur_at
end
it 'does not change timings' do
expect(consumption.occur_at).to equal(valid.occur_at)
end

11. #10 I don’t have the time...
rspec spec/models/user_spec.rb
1. bundle exec guard # or zeus, spork, spin
2. rspec spec/models/user_spec.rb -l 10
3. rspec --no-drb spec/models/*

12. #11 External is slow. :/
require 'open-uri'
file = open('http://otobrglez.opalab.com')
contents = file.read
puts contents
context "blog" do
let(:uri) { 'http://otobrglez.opalab.com' }
before { stub_request(:get, uri).to_return(status: 200, body: fixture('home.html'))
}
it "gets home page" do
# magic here...
expect(page).to have_content 'Oto Brglez'
end
end

13. What else?
1. Use formatters
2. Test what you see
3. Test edge-cases
4. Learn how to mock/stub
5. Decuple your code
6. Think about CI
7. Keep your tests fast and readable
8. Learn from OS projects

14. Thanks
Inspired by betterspecs.org and nasty test suites.
Read my blog; and be ql.
- Oto