Test Driven Development

TDD meetup slides at PHP Reboot on 8th April, 2017.

Transcript

1. PHPReboot.com Kapil Sharma TDD Test Driven Development
2. PHPReboot.com Kapil Sharma About me • Kapil Sharma. • Technical Architect at Eastern Enterprise. • Working in Web Application development since 12+ years. • Twitter: @kapilsharmainfo • Facebook: /kapilsharmainfo • Linked in: kapilsharmainfo • Website: kapilsharma.info • Slides: speakerdeck.com/kapilsharma 2
3. PHPReboot.com Kapil Sharma About PHPReboot 3 • PHP developers community in Pune, India. • Conduct regular meet ups • meetup.com/phpreboot • phpreboot.com • Twitter: @phpreboot • Facebook: /PHReboot • Slack: phpreboot.signup.team • Virtual team developing open source. • PHP Magazine at phpreboot.com. • PHPreboot.com is open source website • github.com/phpreboot/website • Issues: waffle.io/phpreboot/ website • Contributions welcome.
4. PHPReboot.com Kapil Sharma – Wikipedia “Test-driven development (TDD) is a software development process that relies on the repetition of a very short development cycle: requirements are turned into very specific test cases, then the software is improved to pass the new tests, only.” 4 What is TDD?
5. PHPReboot.com Kapil Sharma TDD 5 Write Test Make the test pass. Refactor
6. PHPReboot.com Kapil Sharma Quotes • All code is guilty, until proven innocent. • First, solve the problem. Then, write the code. • Good programmers write code for humans first and computers next. • Don’t fix it if it is ain’t broke. • Quality is free, but only to those who are willing to pay heavily for it. 6
7. PHPReboot.com Kapil Sharma What is TDD? • TDD is test-first approach of software development. • It leads to think ‘How to use’ first and then about ‘How to implement’. 7
8. PHPReboot.com Kapil Sharma TDD Wars • Short story based on Star Wars movie. • Next 4 slides are taken from Michelangelo Van Dam’s (DragonBe) presentation ‘PHPUnit Episode iv.iii: Return of the tests’ • I really like that theme of PHP Unit presentations and wanted to share few slides. • Original presentation: https://www.slideshare.net/ DragonBe/phpunit-episode-iviii-return-of-the-tests 8
9. Source: https://www.slideshare.net/DragonBe/phpunit-episode-iviii-return-of-the-tests
10. Source: https://www.slideshare.net/DragonBe/phpunit-episode-iviii-return-of-the-tests
11. Source: https://www.slideshare.net/DragonBe/phpunit-episode-iviii-return-of-the-tests
12. Source: https://www.slideshare.net/DragonBe/phpunit-episode-iviii-return-of-the-tests
13. PHPReboot.com Kapil Sharma Why developers not writing tests? • No time. • No budget. • Write once project finishes (Never). • We do not know how to write. 13
14. PHPReboot.com Kapil Sharma Responsibility • Developer’s job is to: • Write code. • Fix bugs. • Add documentation. • Write and update unit tests. 14
15. PHPReboot.com Kapil Sharma Benefits of testing • Direct feedback (test fails). • Once a test is made, it will always be tested. • Easy to refactor existing code (protection). • Easy to debug: Write a test to verify if bug is valid. • Higher confidence and less uncertainty. 15
16. PHPReboot.com Kapil Sharma – Martin Fowler “Whenever you are tempted to type something into a print statement or a debugging expression, write it as a test instead.” 16
17. PHPReboot.com Kapil Sharma PHP Unit 17 PHPUnit
18. PHPReboot.com Kapil Sharma PHP Unit • PHPUnit is a port of xUnit testing framework. • Created by Sebastian Bergmann. • User ‘assertions’ to verify behaviour of ‘unit of code’. • Open source and hosted on Github. • Can be installed using • PHAR • Composer 18
19. PHPReboot.com Kapil Sharma Assertions • assertArrayHasKey • assertClassHasAttribute • assertArraySubset • assertClassHasStaticAttribute • assertContains • assertContainsOnly • assertContainsOnlyInstanceOf • assertCount • assertDirectoryExists • assertDirectoryIsReadable • assertDirectoryIsWritable • assertEmpty() • assertEqualXMLStructure() • assertEquals() • assertFalse() 19 • assertFileEquals() • assertFileExists() • assertFileIsReadable() • assertFileIsWritable() • assertGreaterThan() • assertGreaterThanOrEqual() • assertInfinite() • assertInstanceOf() • assertInternalType() • assertIsReadable() • assertIsWritable() • assertJsonFileEqualsJsonFile() • assertJsonStringEqualsJsonFile() • assertJsonStringEqualsJsonString() • assertLessThan() • assertLessThanOrEqual() • assertNan() • assertNull() • assertObjectHasAttribute() • assertRegExp() • assertStringMatchesFormat() • assertStringMatchesFormatFile() • assertSame() • assertStringEndsWith() • assertStringEqualsFile() • assertStringStartsWith() • assertThat() • assertTrue() • assertXmlFileEqualsXmlFile() • assertXmlStringEqualsXmlFile() • assertXmlStringEqualsXmlString()
20. PHPReboot.com Kapil Sharma Data Providers • We might need same test to be executed against different inputs. • Data providers help providing different data (input) to test method as parameters. 20
21. PHPReboot.com Kapil Sharma Data Providers 21
22. PHPReboot.com Kapil Sharma Data Providers 22
23. PHPReboot.com Kapil Sharma Mocks • Sometime, we can’t test a method because: • It has difficult to resolve dependencies. • It calls another method that we can’t execute. 23
24. PHPReboot.com Kapil Sharma Mocks 24 Source: PHPUnit docs
25. PHPReboot.com Kapil Sharma Lots more to cover • We just saw possibilities at high level. • Refer PHP Unit docs for much more details. • We will cover some of the practical uses in following session and workshop. 25
26. PHPReboot.com Kapil Sharma Thank you. 26 Questions?