Test and API-driven development of CakePHP Behaviors

Test and API-driven development of CakePHP Behaviors

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  Test [and API]driven development of CakePHP Behaviors held by Alexander Morland at CakeFest 2009
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  1. Introduction AlexanderMorland aka 'alkemann' Web technology since 2005 CakePHP since 2007 illustrata.no 2009 Revision Behavior Ordered Behavior Logable Behavior and others
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  Talk overview 1. Introduction Goal: 2. Unit Testing 3. Focus on the API  Share some of the excitement I 4. Why we did it discovered in moving the logic 5. The Devide and Conquer to the right place and code it in 6. Example a way that makes sense.  7. CakePHP and SimpleTest 8. Lessons learned 9. Summary
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  2. Unit Testing Incomputer programming, unit testing is a software verification and validation method where the programmer gains confidence that individual units of source code are fit for use. A unit is the smallest testable part of an application. [..] in object-oriented programming, the smallest unit is a method,[..] from: http://en.wikipedia.org/wiki/Unit_test Design Documentation Simplifies integration Facilitates change Enables Divide and Conquer development
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  3. API writing 1. Follow existing api  2. Implement abstract classes 3. Hook into Cake callbacks 4. Keep it simple Model::delete( $id = NULL, $cascade = true ) delete( $id = NULL, $custom = '', $cascade = true ) vs. delete( $id = NULL, $cascade = true, $custom = '' )
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  4. Why wedid it? 1. Move from single developer to team 2. Consistent code, in-house, core and community 3. Cyclic development
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  5. The Divideand Conquer 1. Brainstorm function 2. Brainstorm implementation 3. Specifications of features 4. Write the API 5. Parallel or sequential : Writing a test case Implement code against test 6. Write tests for feature spec Write tests trying to use wrongly / error   7. Code Review
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  6. Example -ColourBehavior What:  add colour on save easy find by colour How: beforeSave() colour('red') Tests:  save() colour() find()
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  Behavior method: 1. /** 2.* Returns a findByColour of the given colour 3. * 4. * @param Object $Model 5. * @param $colour Colour to filter model by 6. * @return string a english worded colour 7. */ 8. public function colour(&$Model, $colour) { 9. return $Model->findAllByColour($colour); 10. } Test code: 1. $findBy = $Nose->findByColour('red'); 2. $expected = array('Nose' => array(0 => array('id' => 3, 'owner' => 'Rudolf', 'colour' => 'Red' ))); 3. $this->assertEqual($findBy, $expected, 'Data corrupt : %s'); 4. /**/ 5. $check = $Nose->colour('red'); 6. $this->assertEqual($check, $findBy, 'Different result than findByColour : %s'); 7. $this->assertEqual($check, $expected, 'Incorrect result : %s');
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  Behavior method: 1./** 2. * When saving new rows and a colour is not set, insert colour into dataset 3. * It does this by checking if neither id or colour field is in the dataset 4. */ 5. public function beforeSave(&$Model) { 6. if ( 7. !isset($Model->data[$Model->alias][$Model->primaryKey]) 8. && 9. !isset($Model->data[$Model->alias]['colour']) 10. ) { 11. $Model->data[$Model->alias]['colour'] = $this->random($Model); 12. } 13. return true; 14. } Test code: 1. $Nose->create(array('owner' => 'Alexander'); 2. $Nose->save(); 3. $result = $Nose->read(); 4. $this->assertNotNull($result['Nose']['colour'], 'Did not get a colour : %s'); 5. /**/ 6. $Nose->create(array('owner' => 'Superman', 'colour' => 'Cryptonite'); 7. $Nose->save(); 8. $result = $Nose->read(); 9. $this->assertEqual($result['Nose']['colour'],'Cryptonite', 'Interference : %s');
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  7. CakePHP andSimpleTest Cake uses SimpleTest as vendor (www.simpletest.org) domain.com/test.php Run Example
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  8. Lessons learned 1. Tests could be written blindly 2. Usage in focus produced better api 3. Complete project just with test 4. Shared code early, feedback early 5. Test, Brute-force, Optimize 6. Start simple and expand 7. Test compatibility with other Behaviors 8. It was fun!
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  In closing Be your own giant! thanks for listening