Outside in BDD

How to develop software that matters using outside in behaviour driven developmend

Transcript

1. Outside in Behaviour Driven Development with Magento. Adding value with example based features. James Cowie
2. Who am I • James Cowie • Software Engineer • Session Digital • BDD Practitioner • @jcowie • github.com/jamescowie
3. Software development problems
4. Traditional Software Development • Slow feedback cycles • Expensive to change • Upfront documentation
5. Waterfall Requirements Analysis Design Code Test
6. Agile to the rescue!!
7. Agile 2001 • Start the conversation • Iterations • Process of engagement
8. TDD / Agile Cycle Requirements Acceptance Design Code Test ~20 minutes
9. Introducing BDD “Software development practice that emphasises development through an example-based conversations with users and stakeholders of the system.“
10. Evolution / Process of BDD • Inspired by eXtreme programming and Agile • Example workshops • User stories • Story mapping
11. • Evolved from Test-first development • Common language • Behaviour • Discovering and delivery what matters most first What is BDD
12. BDD Cycle Narrative Why? Examples Implement Refactor Describe How
13. BDD Tools Implementation === PHPSpec Conversation === Behat
14. Domain Specific Tools BehatMage MageSpec
15. The requirement Hello Development Agency, We have found that lots of our customers tweet about the products they are buying from our website. Can you include a twitter widget on the productpage and we can configure a message via the admin section ? We think this will encourage more people to share the products on the timeline and increase our sales. Hope this is ok. Client
16. Setting up the tools { "require": { "php": ">=5.4.0" }, "require-dev": { "magetest/magento-phpspec-extension": "2.1.*", "magetest/magento-behat-extension": "dev-feature/Behat3", "bossa/phpspec2-expect": "dev-master" }, "config": { "bin-dir": "bin" }, "autoload": { "psr-0": { "MageTest\\PhpSpec\\MagentoExtension": "src", "": [ "public/app/code/local", "public/app/code/community", "public/app/code/core", "public/app", "public/lib" ], "Mage" : "public/app/code/core" } } }
17. Behat.yml default: suites: default: paths: features: features/visitor contexts: - VisitorBrowsingContext extensions: MageTest\MagentoExtension\Extension: ~ base_url: http://magento.local/ Conversation
18. phpspec.yml extensions: - MageTest\PhpSpec\MagentoExtension\Extension mage_locator: spec_prefix: 'spec' src_path: 'public/app/code' spec_path: 'spec/public/app/code' Implementation
19. What makes a story Given When Then Context: The context for this specific scenario, for example Given the customer is logged in. Event: What the feature should be doing, for example When the customer clicks add to cart. Outcome: The expected result from a given context and event. Example: “Then the product should be added to the shopping cart.”
20. Narrative Feature: Visitors can share via twitter In order to allow visitors to share our products As a site owner I need to offer a way to share via twitter my products Scenario: Visitor can share a product via twitter Given I have twitter enabled with a username When I view a product page Then I should see a twitter block with my message configured
21. Running Behat ➜ Magento behat Feature: Any customer to the site will see a twitter widget on the product page In order to allow visitors to share our products As a site owner I need to offer a way to share via twitter my products Scenario: Visitor can share a product via twitter Given I have twitter enabled with a username TODO: write pending definition When I view a product page Then I should see a twitter block with my message configured # 1 scenario (1 pending) 3 steps (1 pending, 2 skipped) 0m0.03s (16.09Mb)
22. Behat Contexts <?php
 
 use Behat\Behat\Tester\Exception\PendingException;
 use Behat\Behat\Context\Context;
 use Behat\Behat\Context\SnippetAcceptingContext;
 use MageTest\MagentoExtension\Context\MagentoContext; class VisitorBrowsingContext extends MagentoContext implements Context, SnippetAcceptingContext
 {
 /*
 * @Given I have twitter enabled with a username
 */
 public function iHaveTwitterEnabledWithAUsername()
 {
 $configValue = Mage::getStoreConfig('jcowie/twitter/ active_username');
 if (isset($configValue)) {
 return true;
 } else {
 throw new RuntimeException('System configuration value not found');
 }
 }
 

23. ➜ Magento behat Feature: A visitor can share via twitter In order to allow visitors to share our products As a site owner I need to offer a way to share via twitter my products Scenario: Visitor can share a product via twitter6 Given I have twitter enabled with a username System configuration value not found (RuntimeException) When I view a product page Then I should see a twitter block with my message configured --- Failed scenarios: features/visitor/twitter-integration.feature:6 1 scenario (1 failed) 3 steps (1 failed, 2 skipped) 0m0.02s (16.08Mb)
24. PHPSpec Object Expectation Matcher $result ->should() ->shouldNot() ->be…() ->notBe()
25. Describe a new block ./bin/phpspec describe:block jcowie_twitter/twitter Specification for Jcowie_Twitter_Block_Twitter created in /vagrant/spec/ public/app/code/local/Jcowie/Twitter/Block/TwitterSpec.php. ./bin/phpspec r Jcowie_Twitter_Block_Twitter 10 ! it is initializable class Jcowie_Twitter_Block_Twitter does not exist. 94% 16 4 specs 16 examples (15 passed, 1 broken) 308ms Do you want me to create `Jcowie_Twitter_Block_Twitter` for you? [Y/n] Y Magento block Jcowie_Twitter_Block_Twitter created in '/vagrant/public/ app/code/local/Jcowie/Twitter/Block/Twitter.php'.
26. Describe the class behaviour <?php
 
 namespace spec;
 
 use PhpSpec\ObjectBehavior;
 use Prophecy\Argument;
 
 class Jcowie_Twitter_Block_TwitterSpec extends ObjectBehavior
 {
 function it_should_return_the_twitter_username_and_url()
 {
 $this->getTwitterShareUrl() ->shouldReturn('http://twitter.com/jcowie');
 }
 }

27. ./bin/phpspec r Jcowie_Twitter_Block_Twitter 15 ! it should return the configured twitter username and tweet url method Jcowie_Twitter_Block_Twitter::getTwitterShareUrl not found. 50% 50% 2 1 specs 2 examples (1 passed, 1 broken) 36ms Do you want me to create `Jcowie_Twitter_Block_Twitter::getTwitterShareUrl()` for you? [Y/n] Y Method Jcowie_Twitter_Block_Twitter::getTwitterShareUrl() has been created. ./bin/phpspec r Jcowie_Twitter_Block_Twitter 15 ✘ it should return the configured twitter username and tweet url expected "http://twitter.com/jcowie"..., but got null. 50% 50% 2
28. What just happened ? • $this in spec refers to the class being tested • PHPSpec created the method for us <?php
 
 class Jcowie_Twitter_Block_Twitter
 {
 public function getTwitterShareUrl()
 {
 // TODO: write logic here
 }
 }

29. Return back to green 100% 2 1 specs 2 examples (2 passed) 30ms <?php
 
 class Jcowie_Twitter_Block_Twitter
 {
 public function getTwitterShareUrl()
 {
 return 'http://twitter.com/jcowie';
 }
 }

30. Refactor • Mage:: • Specs should not talk to other classes • Don’t spec code you do not own • Database calls
31. How to mock Magento
32. Using adapters <?php 
 
 class Jcowie_Twitter_Model_Adapter_ConfigAdapter
 {
 public function getCoreConfigValue($path)
 {
 return Mage::getStoreConfig($path);
 }
 } 
 Don’t test what we Don’t Own!
33. Inject into the block private $_configAdapter;
 
 public function __construct(array $services = array())
 {
 if (isset($services['config_adapter'])) {
 $this->_configAdapter = $services['config_adapter'];
 }
 if ( !$this->_configAdapter instanceof Jcowie_Twitter_Model_.._ConfigAdapter){
 $this->_configAdapter = new Jcowie_Twitter_Model_Adapter_ConfigAdapter();
 }
 } Dependency Injection
34. Refactor public function getTwitterShareUrl()
 {
 return 'http://twitter.com/' . $this-> _configAdapter ->getCoreConfigValue('jcowie/twitter/ twitter_username');
 }
35. Update the spec function let(\Jcowie_Twitter_Model_Adapter_ConfigAdapter $adapter)
 {
 $this->beConstructedWith(array('config_adapter' => $adapter));
 }
 
 function it_should_return_the_twitter_username_and_url($adapter)
 {
 $adapter->getCoreConfigValue(‘jcowie/twitter/twitter_username') ->willReturn(‘jcowie'); 
 $this->getTwitterShareUrl()->shouldReturn('http://twitter.com/ jcowie');
 }
 Mock the communication.
36. Back to green ./bin/phpspec r --format=pretty Jcowie_Twitter_Block_Twitter 15 ✔ should return the configured twitter username and tweet url (55ms) 1 specs 1 examples (1 passed)
37. Some steps missing… • Manually create the layout.xml • Manually create the template
38. Back to Behat Feature: Any customer to the site will see a twitter widget on the product page In order to allow visitors to share our products As a site owner I need to offer a way to share via twitter my products Scenario: Visitor can share a product via twitter Given I have twitter enabled with a username When I view a product page Then I should see a twitter block with my message configured 1 scenario (1 passed) 3 steps (3 passed) 0m1.47s (23.14Mb) Time to stop writing code!
39. Lessons Learned • BDD is NOT Behat • Automation is a side effect • Conversation is king • Dont test Magento code.
40. Any Questions ?