Test-Driven Development

• Think of a feature
• Write a failing test
• Make the test pass
• Refactor
• Goto 1
• It forces you to think about your code before writing it.
• It forces your code to be testable. Encourages small and discrete code, which is more reusable.
• It allows you to do refactoring. Maybe you want it to be easier to read, or you come back later and want to do it a different way.
• TDD helps keep new bugs from being introduced.
• How to get started? Find a test library for your language. PHP has simpletest and phpunit. Ruby has Rspec and cucumber. Python, Bash, JavaScript has Mocha. Selenium allows you to browser a browser.
• Unit tests test individual functions seperate from each other.
• Integration tests test the software stack from the perspective of the user. Testing how lots of things work together.
• Continuous integration: with every commit every test is run and the whole team can see what's happening.
• On our team the people writing the code writes the test.
• In pair programming, you could have one developer write the test and have the other person make it pass.
• It's important to write good tests. You can make a terrible test suite that slows down development
• Cucumber allows non-programmers to interact with tests via user stories
• Mocha is a JavaScript test library. Cooper loves it.
• Travis CI is a hosted continuous integration service. Cooper loves it.
• Can run tests headless using jsdom
• Chai provides helper functions for Mocha

Report back

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• Have confidence to add new things and refactor bad code without breaking old code
• We proved without a shadow of a doubt that Ruby can add 2 plus 2. And we have a test for it.