My Top 10 PHPUnit Tips And Tricks

Presented on June 26 2020 at the Dutch PHP Conference Online Edition.
https://schedule.phpconference.nl/talk/2
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Of course you test your code... you may even use test driven development. But do those tests really add value ? Are your tests actually testing your code ? Or are they just there to satisfy the CI process ?

In this talk Juliette will focus on all the things she's learned in years of writing and reviewing tests, the pitfalls she fell into, and the tips and tricks she learned along the way.
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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/

Infection:
Docs: https://infection.github.io/
Demo: https://youtu.be/ADKyTlaH6e4

Transcript

1. My Top 10 PHPUnit Tips & Tricks Juliette Reinders Folmer Tweet about it: @jrf_nl #DPC20 Olivier Issaly
2. Before we start...  Follow along with the code samples used: https://github.com/jrfnl/ top-10-phpunit-tips-tricks- demo  Discuss in Slack channel: #phpunit-tips-and-tricks davidjohn
3. 0. Have Tests
4. 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/"] } }
5. 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> --generate-configuration
6. Start Small (but start somewhere) <?php namespace PHPUnit_Demo; class Foo { static function stripQuotes($string) { return preg_replace( '`^([\'"])(.*)\1$`Ds', '$2', $string ); } } @562a010
7. 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); } } @afda386
8. 1. Use the Right Assertion
9. assertEquals() == assertSame() === Most Common Issue
10. Available Assertions
11. 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); } } @ef6fa43
12. 2. Don't Just Test the Happy Path
13. <?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 @ef108e2
14. Allow for Testing the Unhappy Path  strict_types  Parameter type declarations mensatic
15. 3. Limit Assertions Per Test
18. <?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); } Use Fail Messages @2ccceaf
19. <?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 @2ccceaf
21. 4. Use Data Providers
22. Test Method Data Provider /** * Test Foo::stripQuotes(). * * @dataProvider dataStripQuotes * * @param mixed $in Function input. * @param string $out Expected output. * * @return void */ public function testStripQ($in, $out) { $result = Foo::stripQuotes($in); $this->assertSame($out, $result); } /** * Data provider. * * @return array[] */ public function dataStripQuotes() { return [ ['"some text"', 'some text'], ["some 'text'", "some 'text'"], [false, ''], ]; } @2ccceaf
23. Without Data Provider With Data Provider
24. 5. Don't Use Your Own Code To Create Test Data
25. 6. Name Your Test Cases
27. Named Test Cases /** * Data provider for the testStripQuotes() test. * * @return array[] */ public function dataStripQuotes() { return [ 'double quoted text' => ['"some text"', 'some text'], 'quotes with quoted text within' => ["some 'text'", "some 'text'"], 'not string input - bool' => [false, ''], ]; } @13e218b
29. 7. Explore Filtering
30. Filter Options Filter Shortcuts --filter TestNamespace --filter TestClass --filter testMethod --filter 'TestNS\\TClass::testMethod' --filter 'TestNS\\TestClass' --filter '/::testMethod .*"name"/' --filter '/::testMethod .*#5$/' --filter '/::testMethod .*#(1|2|5)$/' --filter 'testMethod#5' --filter 'testMethod#4-6' --filter '#1' --filter '#1-3' --filter 'testMethod@named test case' --filter 'testMethod@name.*case' --filter '@named test case' --filter '@named.*case'
32. 8. Don't Trust Code Coverage But do examine it
33. <?php namespace PHPUnit_Demo; class Foo { static function stripQuotes($string) { return preg_replace( '`^([\'"])(.*)\1$`Ds', '$2', $string ); } }
34. Enabling Code Coverage [1] <?xml version="1.0" encoding="UTF-8"?> <phpunit beStrictAboutCoversAnnotation="true" forceCoversAnnotation="true" > ... <filter> <whitelist addUncoveredFilesFromWhitelist="true"> <directory suffix=".php">src</directory> </whitelist> </filter> <logging> <log type="coverage-clover" target="build/logs/clover.xml"/> </logging> </phpunit> @1710ccb See also: feature/ update-config-for- phpunit-9.3
35. Enabling Code Coverage [2] <?php class FooTest extends TestCase { /** * Test Foo::stripQuotes(). * * @dataProvider dataStripQuotes * * @covers \PHPUnit_Demo\Foo::stripQuotes */ public function testStripQuotes($in, $out) { $result = Foo::stripQuotes($input); $this->assertSame($expected, $result); } @1710ccb
36. Simplify { "scripts" : { "test": [ "vendor/bin/phpunit --no-coverage" ], "coverage": [ "vendor/bin/phpunit" ], "coverage-local": [ "vendor/bin/phpunit --coverage-html ./build/coverage-html" ] } } @1710ccb
38. 9. Don't Leave Without Saying Goodbye
39. Conditionally Skipping Tests [1] public function testIsCountable($input, $expected) { if (\version_compare(\PHP_VERSION_ID, '70300', '<')) { return; } $this->assertSame($expected, myCountable($input)); } example/test-skipping
40. Conditionally Skipping Tests [2] public function testIsCountable($input, $expected) { if (\version_compare(\PHP_VERSION_ID, '70300', '<')) { $this->markTestSkipped(); return; } $this->assertSame($expected, myCountable($input)); } example/test-skipping
41. Conditionally Skipping Tests [2] public function testIsCountable($input, $expected) { if (\version_compare(\PHP_VERSION_ID, '70300', '<')) { $this->markTestSkipped( 'This test requires PHP 7.3.0+' ); } $this->assertSame($expected, myCountable($input)); } example/test-skipping
42. Conditionally Skipping Tests [4] /** * @requires PHP >= 7.3.0 */ public function testIsCountable($input, $expected) { if (\version_compare(\PHP_VERSION_ID, '70300', '<')) { $this->markTestSkipped( 'This test requires PHP 7.3.0+' ); return; } $this->assertSame($expected, myCountable($input)); } example/test-skipping
43. 10. Make Your Tests Cross-Version Compatibility
44. PHPUnit Support v Compatible with: 9 PHP 7.3, 7.4 (support ends Feb 2022) 8 PHP 7.2, 7.3, 7.4 (support ends Feb 2021) 7 PHP 7.1, 7.2, 7.3 6 PHP 7.0, 7.1, 7.2 5 PHP 5.6, 7.0, 7.1 4 PHP 5.3, 5.4, 5.5, 5.6 Seemann
45. Cross-version Compatible Fixtures public static setupBeforeClass() : void { self::$db = new DBConnector(); } public static tearDownAfterClass() : void { self::$db->disconnect(); }
46. Cross-version Compatible Fixtures /** * @beforeClass */ public static setupBeforeClass() : void { public static setupDBConnection() { self::$db = new DBConnector(); } /** * @afterClass */ public static tearDownAfterClass() : void { public static disconnectDB() { self::$db->disconnect(); unset(self::$db); }
47. 11. Test Your Tests
48. Test Your Tests  Infection https://infection.github.io/ https://youtu.be/ADKyTlaH6e4  PHPUnitCompatibility (upcoming)  PHPUnitQA (upcoming) lisaleo
49. 12. Lose Count
50. Thanks! @jrf_nl @jrfnl Any questions ? Feedback: https://joind.in/talk/2d124 Slides: https://speakerdeck.com/jrf Code: https://github.com/jrfnl/ top-10-phpunit-tips-tricks-demo Docs: https://phpunit.readthedocs.io/