Test-Driven Development

Transcript

1. Sam Starling, BBC Future Media Test-Driven Development
2. Does it work the way it should? Have I broken anything on the way? Is this task done yet?
3. Does it work the way it should? Have I broken anything on the way? Is this task done yet?
4. Does it work the way it should? Have I broken anything on the way? Is this task done yet?
5. Have I done everything I needed to? Does everything I’ve done still work? Can I go to the pub yet?
6. Have I done everything I needed to? Does everything I’ve done still work? Can I go to the pub yet?
7. Have I done everything I needed to? Does everything I’ve done still work? Can I go to the pub yet?
8. How do you test-drive code?
9. RED Write a failing test GREEN Make the test pass REFACTOR Make any changes
10. Why do you test-drive code?
11. 1: Confidence
12. 2: Documentation
13. function sum(a, b) { return a + b }
14. public function getBeacon($seedRandom = false) { // toggle a seeded random number for unit testing if ($seedRandom) { mt_srand(0); } $beaconTokens = array( 's' => 'News', 't' => ($this->getBeaconToken() ?: 0), 'i' => ($this->getAssetId() ?: 0), 'p' => ($this->getSectionId() ?: 0), 'a' => ($this->getEdition() ?: 0), 'u' => ($this->getAsseturi() ?: 0), 'r' => 0, // http_referrer 'q' => 0, // query_string 'z' => mt_rand(1, 10000)); foreach ($beaconTokens as $key => $value) { $this->beacon .= sprintf('~RS~%s~RS~%s', $key, $value); } return $this->beacon . '~RS~'; }
15. itStoresABeaconValue() itUpdatesABeaconValue() itCanOverrideABeaconValue() ...
16. 3: Coupling & Cohesion
17. 4: Cleaner Code
18. Growing Object-Oriented Software Guided by Tests
19. It’s a skill! Learn it by using it
20. bbc.co.uk/jobs/digitalmediascheme Graduate Scheme sam.starling@bbc.co.uk