Test-driven JavaScript development with YUI

Notes from “Test Driven Development with YUI Test” presentation given by Nicholas Zakas

• Flow:
  1. Define requirements
  2. Write tests to verify requirements are met
  3. Write code to test
  4. Run tests
  5. If test succeed, repeat from step 1 until project is finished. If tests fail, repeat from step 3 until tests pass, and then repeat from step 1 until project is finished
• Motivations:
  • Even small changes can break a complex app.  Use unit tests and suites of tests to ensure app integrity after each change to the code base.
  • Tasks become well-defined using this methodology
  • We are best positioned to perform QA because we know our code best
• Tips & tricks:
  • Use a test template to speed up the process
  • Use setUp and tearDown functions to prepare and clean environment, respectively, after each test is run
  • Develop the habit of creating files for code and tests for the code in pairs, e.g. code.js & test_code.js
  • In general, each method gets a test and each object gets a test case
  • In your build process, define a “test” state that inserts YUI test code into the app code base
• References:
  • Presentation slides by Zakas
  • YUI docs