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
   

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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
   

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3. 0.
   Have Tests
   

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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/"]
   }
   }
   

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5. Have the basic
   setup in place [2]
   In phpunit.xml.dist:
   
   bootstrap="./vendor/autoload.php"
   colors="true"
   >
   
   
   
   ./tests/
   
   
   
   
   --generate-configuration
   

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6. Start Small
   (but start somewhere)
   namespace PHPUnit_Demo;
   class Foo
   {
   static function stripQuotes($string)
   {
   return preg_replace(
   '`^([\'"])(.*)\1$`Ds',
   '$2',
   $string
   );
   }
   }
   @562a010
   

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7. Start Small
   (but start somewhere)
   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
   

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8. 1.
   Use the Right Assertion
   

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9. assertEquals()
   ==
   assertSame()
   ===
   Most Common Issue
   

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10. Available Assertions
    

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11. Use the
    Right Assertion
    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
    

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12. 2.
    Don't Just Test
    the Happy Path
    

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13. 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
    

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14. Allow for Testing the
    Unhappy Path
     strict_types
     Parameter type
    declarations
    mensatic
    

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15. 3.
    Limit Assertions
    Per Test
    

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16. View Slide

17. View Slide

18. 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
    

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19. 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
    

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21. 4.
    Use Data Providers
    

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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
    

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23. Without Data Provider
    With Data Provider
    

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24. 5.
    Don't Use Your Own Code
    To Create Test Data
    

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25. 6.
    Name Your Test Cases
    

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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
    

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29. 7.
    Explore Filtering
    

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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'
    

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31. View Slide

32. 8.
    Don't Trust Code Coverage
    But do examine it
    

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33. namespace PHPUnit_Demo;
    class Foo
    {
    static function stripQuotes($string)
    {
    return preg_replace(
    '`^([\'"])(.*)\1$`Ds',
    '$2',
    $string
    );
    }
    }
    

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34. Enabling Code
    Coverage [1]
    
    beStrictAboutCoversAnnotation="true"
    forceCoversAnnotation="true"
    >
    ...
    
    addUncoveredFilesFromWhitelist="true">
    src
    
    
    
    target="build/logs/clover.xml"/>
    
    
    @1710ccb
    See also:
    feature/
    update-config-for-
    phpunit-9.3
    

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35. Enabling Code
    Coverage [2]
    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
    

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36. Simplify
    {
    "scripts" : {
    "test": [
    "vendor/bin/phpunit --no-coverage"
    ],
    "coverage": [
    "vendor/bin/phpunit"
    ],
    "coverage-local": [
    "vendor/bin/phpunit
    --coverage-html ./build/coverage-html"
    ]
    }
    }
    @1710ccb
    

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38. 9.
    Don't Leave Without
    Saying Goodbye
    

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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
    

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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
    

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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
    

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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
    

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43. 10.
    Make Your Tests
    Cross-Version Compatibility
    

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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
    

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45. Cross-version Compatible Fixtures
    public static setupBeforeClass() : void {
    self::$db = new DBConnector();
    }
    public static tearDownAfterClass() : void {
    self::$db->disconnect();
    }
    

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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);
    }
    

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47. 11.
    Test Your Tests
    

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48. Test Your Tests
     Infection
    https://infection.github.io/
    https://youtu.be/ADKyTlaH6e4
     PHPUnitCompatibility
    (upcoming)
     PHPUnitQA
    (upcoming)
    lisaleo
    

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49. 12.
    Lose Count
    

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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/
    

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