tdd-rails.md

Why do TDD?

• Business requirements
• Make sure it works
• Adding features months later
• Tests act as documentation
• Code is easier to refactor
• Easier to modify/extend code
• Code is written quickly by helping to guide the design decisions
• Validates we are writing code that actually works
• Helps developers hone in on writing code that is absolutely necessary
• Helps establish trust among the team

Acceptance Tests: High level tests, driven from the user or customer of the actual web applciation. They would be performing high level actions.

Unit Tests: At a much lower level. Given a state we need to calc the right sales tax, etc. Isolates small components of the application.

Useful Testing Tools

• Factory Girl
• Shoulda Matchers
• DatabaseCleaner - ensure we have a clean slate between test runs

TIP run rails g to see a list of generators you have available

Stubs allow you call a method Mocks expect you to call a method on the object

TIP: When using database_cleaner you will want to turn off transactional fixtures

# DB cleaner configuration from Avdi Grimm
RSpec.configure do |config|

  config.before(:suite) do
    DatabaseCleaner.clean_with(:truncation)
  end

  config.before(:each) do
    DatabaseCleaner.strategy = :transaction
  end

  config.before(:each, :js => true) do
    DatabaseCleaner.strategy = :truncation
  end

  config.before(:each) do
    DatabaseCleaner.start
  end

  config.after(:each) do
    DatabaseCleaner.clean
  end

end

Transactional fixtures true will clear the entire test database after the test is run, however sometimes there are errors where models will get persisted when you don't want it to.