Unit Testing 

What is unit testing? 

unit tests determine if small units of source code are fit for use What is unit testing? 

unit tests determine if small units of source code are fit for use What is unit testing? 

unit tests determine if small units of source code are fit for use What is unit testing? 

Why Test Code? 6Reasons 

1 Prove that code actually works 

1 Prove that code actually works 2 Improve the design without breaking it 

1 Prove that code actually works 2 Improve the design without breaking it 3Detect regressions 

1 Prove that code actually works 2 Improve the design without breaking it 3Detect regressions 4 Provides sample code 

1 Prove that code actually works 2 Improve the design without breaking it 3Detect regressions 4 Provides sample code 5 Forces you to plan before you code 

1 Prove that code actually works 2 Improve the design without breaking it 3Detect regressions 4 Provides sample code 5 Forces you to plan before you code 6 Reduces bugs 

1 Prove that code actually works 2 Improve the design without breaking it 3Detect regressions 4 Provides sample code 5 Forces you to plan before you code 6 Reduces bugs 

Prove Code Works function add($a, $b) { $x = $a + $b; return $x; } How do we know this works? 

Prove Code Works function some_complex_formula($a, $b) { $x = ($a * 2.3747); $y = ($b ^ 3); return $y; $z = $y - $x; return $z; } 

Prove Code Works function some_complex_formula($a, $b) { $x = ($a * 2.3747); $y = ($b ^ 3); return $y; $z = $y - $x; return $z; } 

Prove Code Works function getLexileScore($ability_prior, $sigma_prior, $raw_score, $num_days, $item_difficulties, $item_difficulties_count) { if (is_array($item_difficulties)) { $item_difficulties = rawurlencode(implode(‘,’, $item_difficulties)); } if (is_array($item_difficulties_count)) { $item_difficulties_count = rawurlencode(implode(‘,’, $item_difficulties_count)); } $postdata = array( ‘ability_prior’ => $ability_prior, ‘sigma_prior’ => $sigma_prior, ... ); $postdata = http_build_query($postdata); $ch = curl_init(URL_LEXILE_SCORE.’/score_test.xml’); curl_setopt($ch, CURLOPT_POST, true); curl_setopt($ch, CURLOPT_POSTFIELDS, $postdata); ... } Real world example: 

Prove Code Works function getLexileScore($ability_prior, $sigma_prior, $raw_score, $num_days, $item_difficulties, $item_difficulties_count) { if (is_array($item_difficulties)) { $item_difficulties = rawurlencode(implode(‘,’, $item_difficulties)); } if (is_array($item_difficulties_count)) { $item_difficulties_count = rawurlencode(implode(‘,’, $item_difficulties_count)); } $postdata = array( ‘ability_prior’ => $ability_prior, ‘sigma_prior’ => $sigma_prior, ... ); $postdata = http_build_query($postdata); $ch = curl_init(URL_LEXILE_SCORE.’/score_test.xml’); curl_setopt($ch, CURLOPT_POST, true); curl_setopt($ch, CURLOPT_POSTFIELDS, $postdata); ... } $item_difficulties = rawurlencode(implode(‘,’, $item_difficulties)); $item_difficulties_count = rawurlencode(implode(‘,’, $item_difficulties_count)); $postdata = http_build_query($postdata); Real world example: 

1 Prove that code actually works 2 Improve the design without breaking it 3Detect regressions 4 Provides sample code 5 Forces you to plan before you code 6 Reduces bugs 

Improve Design function hash_password($input, $cost = 10) { $salt = ‘$2a$’ . str_pad($cost, 2, ‘0’, STR_PAD_LEFT) . ‘$’; $salt .= substr(str_replace(‘+’, ‘.’, base64_encode(openssl_random_pseudo_bytes(16))), 0, 22); return crypt($input, $salt); } 

Improve Design function hash_password($input, $cost = 10) { return crypt($input, generate_salt($cost)); } function generate_salt($cost = 10) { if ($cost < 4 || $cost > 31) { throw new Exception(‘Cost must be between 4 and 31’); } $salt = ‘$2a$’ . str_pad($cost, 2, ‘0’, STR_PAD_LEFT) . ‘$’; $salt .= substr(str_replace(‘+’, ‘.’, base64_encode(openssl_random_pseudo_bytes(16))), 0, 22); return $salt; } Step 3 in Test Driven Development 

1 Prove that code actually works 2 Improve the design without breaking it 3Detect regressions 4 Provides sample code 5 Forces you to plan before you code 6 Reduces bugs 

Detect Regressions -Regressions are things that used to work but no longer do. -When you make a change to code, how do you know if it will affect more then just code you are editing? -With tests, you can know for sure if everything is working as it was. 

1 Prove that code actually works 2 Improve the design without breaking it 3Detect regressions 4 Provides sample code 5 Forces you to plan before you code 6 Reduces bugs 

Sample Code - Source code can be hard to read. - Docblocks are only so helpful. - Tests provide the code being used, no guessing how it works. 

1 Prove that code actually works 2 Improve the design without breaking it 3Detect regressions 4 Provides sample code 5 Forces you to plan before you code 6 Reduces bugs 

Plan Tests force you to think about what code should do, what values are being returned and how to get to there. 

1 Prove that code actually works 2 Improve the design without breaking it 3Detect regressions 4 Provides sample code 5 Forces you to plan before you code 6 Reduces bugs 

Reduces Bugs -Notice I didn’t say prevents. -Like it or not, bugs are a part of code, but validating code can reduce the number of bugs introduced. 

methodology Test Driven Development Behavior Driven Development Domain Driven Development 

Test Driven Development - TDD or Test-First Development is a process where tests are written before any code is. - There are 3 steps in TDD. 1. Write tests that fail. 2. Write code to make them pass. 3. Refactor code. 4. Repeat 

Behavior Driven Development - BDD is an agile method of testing. - Tests uses real world examples. - It - Should - Given - Keywords: 

Domain Driven Development - DDD is business model of testing. - The core model of the business is the basis for all designs and tests. - Initiates a collaboration between the technical and business side of a project to get to the heart of the problem. 

theory Set up conditions for testing Call the method being tested Verify the results Clean up 

theory Tests should be independent Give tests clear, verbose names Don’t run unneeded assertions 

Test Frameworks PHP JavaScript Ruby Shell PHPUnit FUnit (http://www.phpunit.de/) (http://git.io/funit) Jasmine (http://pivotal.github.com/jasmine/) Mocha (http://visionmedia.github.com/mocha/) Test::Unit (standard library) RSpec (http://rspec.info/) Cucumber (http://cukes.info/) shunit2 (http://code.google.com/p/shunit2/) roundup (http://bmizerany.github.com/roundup/) 

Test Frameworks PHP JavaScript Ruby Shell PHPUnit FUnit (http://www.phpunit.de/) (http://git.io/funit) Jasmine (http://pivotal.github.com/jasmine/) Mocha (http://visionmedia.github.com/mocha/) Test::Unit (standard library) RSpec (http://rspec.info/) Cucumber (http://cukes.info/) shunit2 (http://code.google.com/p/shunit2/) roundup (http://bmizerany.github.com/roundup/) 

PHPUnit -Most popular PHP testing framework -TDD with BDD/DDD support -Installed via PEAR -Ability to run tests against a database or mock a third-party service -Had to modify the autoloader method in myOn to get working 

Installing PHPUnit PEAR (http://mlo.io/blog/2012/02/02/perfect- dev-setup-lion.html) pear config-set auto_discover 1 pear install pear.phpunit.de/PHPUnit 

PHPUnit -Class name is the class you are testing followed by Test (tests for Foo would be FooTest) * most of the time -Inherits from PHPUnit_Framework_TestCase* -Test cases are public methods starting with test -File name should match class name 

PHPUnit assertEquals(552, $score[‘score’]); $this->assertEquals(92, $score[‘sigma’]); $score = Lexile::getLexileScore(0, 0, 35, 10, 550, 35); $this->assertEquals(7, $score[‘score’]); $this->assertEquals(5, $score[‘sigma’]); } public function testForecast() { ... } } Example 

PHPUnit -Fixtures allow you to make sure the conditions for each test are the same protected function setUp() { ... } setUp - ran before each test protected function tearDown() { ... } tearDown - ran after each test protected static function setUpBeforeClass() { ... } setUpBeforeClass - static method called before any test protected static function tearDownAfterClass() { ... } tearDownAfterClass - static method called after all test 

PHPUnit -Tests are run with the ‘phpunit’ command -Last parameter is a single file or directory -Options * --bootstrap - File that is run before tests phpunit --bootstrap includes/app/config.php --verbose LexileTest phpunit --bootstrap includes/app/config.php --verbose tests 

PHPUnit More documentation at http://www.phpunit.de/manual/current/en/ index.html 

Test Frameworks PHP JavaScript Ruby Shell PHPUnit FUnit (http://www.phpunit.de/) (http://git.io/funit) Jasmine (http://pivotal.github.com/jasmine/) Mocha (http://visionmedia.github.com/mocha/) Test::Unit (standard library) RSpec (http://rspec.info/) Cucumber (http://cukes.info/) shunit2 (http://code.google.com/p/shunit2/) roundup (http://bmizerany.github.com/roundup/) 

FUnit -Not to be confused with the Flex testing framework of the same name -Simple Unit tests for PHP 5.3+ -Single file -Colored output -Couldn’t find an easy way to test multiple files -Doesn’t provide exit status -No support for BDD or DDD -Easy installation git clone https://github.com/funkatron/FUnit.git 

FUnit

FUnit -Tests are run with fu::run method -Call file with php command

FUnit More documentation at http://git.io/funit 

Test Frameworks PHP JavaScript Ruby Shell PHPUnit FUnit (http://www.phpunit.de/) (http://git.io/funit) Jasmine (http://pivotal.github.com/jasmine/) Mocha (http://visionmedia.github.com/mocha/) Test::Unit (standard library) RSpec (http://rspec.info/) Cucumber (http://cukes.info/) shunit2 (http://code.google.com/p/shunit2/) roundup (http://bmizerany.github.com/roundup/) 

Funsies -Tests must pass before committing -Will not work with FUnit (as it doesn’t give a useful exit status) #!/bin/sh phpunit --bootstrap includes/app/config.php tests exit $? .git/hooks/pre-commit 

Sane Programmers Test Their Code