Adventures In JavaScript Testing
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Thomas Fuchs discusses the importance of testing JavaScript code and provides examples of how to do unit testing of JavaScript with tools like Firebug, Test::Unit, and Rake. He addresses common objections to testing JavaScript and provides tips for debugging JavaScript across different browsers.
![assertEnumEqual(expected, actual)
assertEnumEqual([1,2],[1,2]) => PASS
assertEqual([1,2],[1,2]) => FAIL
assertEqual does not
compare enum contents](https://image.slidesharecdn.com/adventuresinjavascripttesting-090706070633-phpapp01/85/Adventures-In-JavaScript-Testing-23-320.jpg)
![assertType(expected, actual)
assertType(String,’a’) => PASS
assertType(Number,1) => PASS
assertType(Array,[1,2]) => PASS
checks for a specific
constructor](https://image.slidesharecdn.com/adventuresinjavascripttesting-090706070633-phpapp01/85/Adventures-In-JavaScript-Testing-28-320.jpg)
Adventures In JavaScript Testing
- 1. Thomas Fuchs Adventures in JavaScript Testing
- 5. alert(“please use me only where appropriate!”);
- 6. why?
- 7. "JavaScript is this thing for funny mouse trails, right?"
- 9. "WE DON'T NEED NO STINKIN' TESTS FOR TEN LINES OF CODE!"
- 10. "ANYWAY, THERE IS NO WAY TO AUTOMATICALLY TEST JAVASCRIPT!"
- 11. all of this is pure FUD
- 14. s from B orrow nit Test::U
- 16. a DIV is required for containing the test results (defaults to "testlog")
- 17. create a new instance of Test.Unit.Runner…
- 18. …this will excute all methods starting with "test"
- 19. assert away!
- 20. (syntax strangeness for more convenience when calling assertions)
- 21. assert(expression) assert(true) => PASS assert(false) => FAIL assert(2*2==4) => PASS
- 22. assertEqual(expected, actual) assertEqual(‘a’,’a’) => PASS assertEqual(‘a’,’b’) => FAIL assertEqual(1,1) => PASS assertEqual(1,’1’) => PASS does not compare type
- 23. assertEnumEqual(expected, actual) assertEnumEqual([1,2],[1,2]) => PASS assertEqual([1,2],[1,2]) => FAIL assertEqual does not compare enum contents
- 24. assertNotEqual(expected, actual) assertNotEqual(‘a’,’a’) => FAIL assertNotEqual(‘a’,’b’) => PASS assertNotEqual(1,1) => FAIL assertNotEqual(1,’1’) => FAIL does not compare type
- 25. assertMatch(expected, actual) assertMatch(/a/,’a’) => PASS assertMatch(/a/,’bab’) => PASS assertMatch(/a/,’b’) => FAIL assertMatch(/^moo$/,’moo’) => PASS
- 26. assertIdentical(expected, actual) assertIdentical(‘a’,’a’) => PASS assertIdentical(1,’1’) => FAIL compares type
- 27. assertNotIdentical(expected, actual) assertNotIdentical(‘a’,’a’) => FAIL assertNotIdentical(1,’1’) => PASS compares type
- 28. assertType(expected, actual) assertType(String,’a’) => PASS assertType(Number,1) => PASS assertType(Array,[1,2]) => PASS checks for a specific constructor
- 29. assertRaise(exceptionName, method) assertRaise(‘ElementDoesNotExistError’, function(){ new Effect.Opacity(‘invalid-element’) } ); related effects.js code
- 31. assertVisible(element) assertNotVisible(element) also checks if any parent elements are hidden and fails/passes on that
- 32. info(message) Displays arbitrary messages in the "Message" column of the test result
- 34. "WELL, WHAT ABOUT FUNCTIONS THAT RUN ASYNCHRONOUSLY?"
- 35. wait(milliseconds, method) should be last statement in the test (but can be nested)
- 36. Benchmarking
- 37. "WELL, NICE. BUT IT'S TEDIOUS TO RUN ALL THOSE TESTS MANUALLY!"
- 38. rake to the rescue
- 43. rake test:javascripts 1. launches web server 2. controls browsers WEBrick lists results SUCCESS FAILURE ERROR 3. run tests
- 44. $ script/generate javascript_test muhaha exists test/javascript create test/javascript/muhaha_test.html
- 45. just add your tests
- 46. (symlink required: app/test/javascript/assets to app/vendor/plugins/javascript_test/assets)
- 47. Browser definitions (add more!)
- 48. $ script/plugin install http://dev.rubyonrails.org/svn/rails/plugins/javascript_test
- 49. …and if something breaks?
- 50. ≈ Firebug sliced bread http://www.flickr.com/photos/teagrrl/78941282/
- 51. Firebug Debugger
- 54. Safari Debugging
- 55. Microsoft Script Debugger for IE http://blogs.msdn.com/ie/archive/2004/10/26/247912.aspx
- 56. Test with all browsers you want to support
- 58. get a setup that doesn‘t suck
- 60. + + 2 VMs: IE 6 IE 7
- 61. + + one machine to rule them all
- 62. #prototype (freenode) and Rails Spinoffs Google Group