My Top 10 PHPUnit Tips And Tricks

Presented on February 26 2020 at the Confoo conference, Montreal, Canada.
https://confoo.ca/en/yul2020/session/my-top-10-phpunit-tips-tricks
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Of course you test your code... you may even use test driven development.
But are your tests actually testing your code ? Or are they just there to satisfy the CI process ?

In this talk Juliette will focus on the tips and tricks she learned over the years.

Learn how to improve your test setup, what assertions to use when, why data providers are incredibly useful and how to make your tests more descriptive and easier to debug.
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Links:
Code used in the presentation:
https://github.com/jrfnl/top-10-phpunit-tips-tricks-demo

PHPUnit Docs:
https://phpunit.readthedocs.io/

Transcript

1. My Top 10 PHPUnit Tips & Tricks Juliette Reinders Folmer Tweet about it: @jrf_nl #Confoo20 Olivier Issaly
2. 0. Have Tests
3. Have the basic setup in place [1] In composer.json: { "require-dev" : { "phpunit/phpunit": "^8.0 || ^9.0" }, "autoload": { "classmap": ["src/"] }, "autoload-dev": { "classmap": ["tests/"] } }
4. Have the basic setup in place [2] In phpunit.xml.dist: <?xml version="1.0" encoding="UTF-8"?> <phpunit bootstrap="./vendor/autoload.php" colors="true" > <testsuites> <testsuite name="Foo"> <directory suffix="Test.php"> ./tests/ </directory> </testsuite> </testsuites> </phpunit>
5. Start Small (but start somewhere) <?php namespace PHPUnit_Demo; class Foo { static function stripQuotes($string) { return preg_replace( '`^([\'"])(.*)\1$`Ds', '$2', $string ); } }
6. Start Small (but start somewhere) <?php namespace PHPUnit_Demo\Tests; use PHPUnit\Framework\TestCase; use PHPUnit_Demo\Foo; class FooTest extends TestCase { public function testStripQuotes() { $result = Foo::stripQuotes('"text"'); $this->assertEquals('text', $result); } }
7. 1. Use the Right Assertion
8. assertEquals() == assertSame() === Most Common Issue
9. Available Assertions
10. Use the Right Assertion <?php namespace PHPUnit_Demo\Tests; use PHPUnit\Framework\TestCase; use PHPUnit_Demo\Foo; class FooTest extends TestCase { public function testStripQuotes() { $result = Foo::stripQuotes('"text"'); $this->assertEquals('text', $result); $this->assertSame('text', $result); } }
11. 2. Don't Just Test the Happy Path
12. <?php public function testStripQuotes() { $result = Foo::stripQuotes('"some text"'); $this->assertSame('some text', $result); $result = Foo::stripQuotes("some 'text'"); $this->assertSame("some 'text'", $result); $result = Foo::stripQuotes(false); $this->assertSame('', $result); } Don't Just Test the Happy Path
13. Allow for Testing the Unhappy Path  strict_types  Parameter type declarations mensatic
14. 3. Limit Assertions Per Test
17. <?php public function testStripQuotes() { $result = Foo::stripQuotes('"some text"'); $this->assertSame('some text', $result, 'stripping quotes failed'); $result = Foo::stripQuotes("some 'text'"); $this->assertSame("some 'text'", $result, 'failed with quotes in string'); $result = Foo::stripQuotes(false); $this->assertSame('', $result, 'failed with non-string input'); } Use Fail Messages
19. 4. Use Data Providers
20. Test Method Data Provider /** * Test Foo::stripQuotes(). * * @dataProvider dataStripQuotes * * @param string $in * @param string $out * * @return void */ public function testStripQ($in, $out) { $result = Foo::stripQuotes($in); $this->assertSame($out, $result); } /** * Data provider. * * @return array[] */ public function dataStripQuotes() { return [ ['"some text"', 'some text'], ["some 'text'", "some 'text'"], [false, ''], ]; }
21. 5. Don't Use Your Own Code To Create Test Data
22. 6. Name Your Test Cases
24. Named Test Cases /** * Data provider for the testStripQuotes() test. * * @return array[] */ public function dataStripQuotes() { return [ 'double quoted text' => ['"some text"', 'some text'], 'quotes with quoted text within' => ["some 'text'", "some 'text'"], 'not string input - bool' => [false, ''], ]; }
26. 7. Explore Filtering
27. Filter Options Filter Shortcuts --filter TestNamespace --filter TestClass --filter testMethod --filter 'TestNS\\TClass::testMethod' --filter 'TestNS\\TestClass' --filter '/::testMethod .*"name"/' --filter '/::testMethod .*#5$/' --filter '/::testMethod .*#(1|2|5)$/' --filter 'testMethod#5' --filter 'testMethod#4-6' --filter '#1' --filter '#1-3' --filter 'testMethod@named test case' --filter 'testMethod@name.*case' --filter '@named test case' --filter '@named.*case'
29. 8. Don't Trust Code Coverage But do examine it
30. <?php namespace PHPUnit_Demo; class Foo { static function stripQuotes($string) { return preg_replace( '`^([\'"])(.*)\1$`Ds', '$2', $string ); } }
31. Enabling Code Coverage [1] <?xml version="1.0" encoding="UTF-8"?> <phpunit beStrictAboutCoversAnnotation="true" forceCoversAnnotation="true"> <filter> <whitelist addUncoveredFilesFromWhitelist="true"> <directory suffix=".php">src</directory> </whitelist> </filter> <logging> <log type="coverage-clover" target="build/logs/clover.xml"/> </logging> </phpunit>
32. Enabling Code Coverage [2] <?php class FooTest extends TestCase { /** * Test Foo::stripQuotes(). * * @dataProvider dataStripQuotes * * @covers \PHPUnit_Demo\Foo::stripQuotes */ public function testStripQuotes($in, $out) { $result = Foo::stripQuotes($input); $this->assertSame($expected, $result); }
33. Simplify { "scripts" : { "test": [ "vendor/bin/phpunit --no-coverage" ], "coverage": [ "vendor/bin/phpunit" ], "coverage-local": [ "vendor/bin/phpunit --coverage- html ./build/coverage-html" ] } }
35. 9. Don't Leave Without Saying Goodbye
36. public function testStripQuotes($input, $expected) { if (\version_compare(\PHP_VERSION_ID, '70300', '<')) { return; } $this->assertSame($expected, $result); }
37. public function testStripQuotes($input, $expected) { if (\version_compare(\PHP_VERSION_ID, '70300', '<')) { $this->markTestSkipped(); return; } $this->assertSame($expected, $result); }
38. public function testStripQuotes($input, $expected) { if (\version_compare(\PHP_VERSION_ID, '70300', '<')) { $this->markTestSkipped( 'This test requires PHP 7.3.0+' ); return; } $this->assertSame($expected, $result); }
39. /** * @requires PHP >= 7.3.0 */ public function testStripQuotes($input, $expected) { if (\version_compare(\PHP_VERSION_ID, '70300', '<')) { $this->markTestSkipped( 'This test requires PHP 7.3.0+' ); return; } $this->assertSame($expected, $result); }
40. 10. Make Your Tests Cross-Version Compatibility
41. PHPUnit Support v Compatible with: 9 PHP 7.3, 7.4 (support ends Feb 2022) 8 PHP 7.2, 7.3, 7.4 (support ends Feb 2021) 7 PHP 7.1, 7.2, 7.3 6 PHP 7.0, 7.1, 7.2 5 PHP 5.6, 7.0, 7.1 4 PHP 5.3, 5.4, 5.5, 5.6 Seemann
42. Cross-version Compatible Fixtures public static setupBeforeClass() : void { self::$db = new DBConnector(); } public static tearDownAfterClass() : void { self::$db->disconnect(); }
43. Cross-version Compatible Fixtures /** * @beforeClass */ public static setupBeforeClass() : void { public static setupDBConnection() { self::$db = new DBConnector(); } /** * @afterClass */ public static tearDownAfterClass() : void { public static disconnectDB() : void { self::$db->disconnect(); unset(self::$db); }
44. 11. Test Your Tests
45. Test Your Tests  Infection  PHPUnitCompatibility (upcoming)  PHPUnitQA (upcoming) lisaleo
46. 12. Lose Count
47. Thanks! @jrf_nl @jrfnl Any questions ? Slides: https://speakerdeck.com/jrf Code: https://github.com/jrfnl/ top-10-phpunit-tips-tricks-demo Docs: https://phpunit.readthedocs.io/ Feedback: https://joind.in/talk/dafa1