die() hard @ phpse

There are several tools out there for debugging PHP applications, but many developers still prefer cluttering their code with var_dump() and die(). After finding out the reasons for that, we will have a look at the Xdebug extension and it’s relatively new challenger phpdbg.

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1. <?phpeople ?> die() hard Sebastian Heuer PHPSE @ STUDI.SE 19/10/15
2. <?phpeople ?> #software architecture
 #automated testing
 #php
 #redis
 #video game nerd SEBASTIAN HEUER
3. <?phpeople ?> “Debugging is like being the detective in a crime movie where you are also the murderer.” – Filipe Fortes “Crime Scene” by Alan Cleaver, CC BY 2.0, https://www.flickr.com/photos/alancleaver/4121423119
4. <?phpeople ?> What do we need for debugging?
5. <?phpeople ?> CONTROL INSPECTION Breakpoints Stepping Application State Stack Traces MODIFICATION Modify Global State Change Variables
6. <?phpeople ?> CONTROL INSPECTION MODIFICATION 1 <?php 2 3 class SomeWorker 4 { 5 6 /** @var SessionInterface */ 7 private $session; 8 9 /** @var SessionInterface $session */ 10 public function __construct(SessionInterface $session) 11 { 12 $this->session = $session; 13 } 14 15 public function run() 16 { 17 die('reached SomeWorker::run()'); 18 $this->session->put('foo'); 19 $this->session->put('bar'); 20 } 21 22 }
7. <?phpeople ?> 1 <?php 2 3 class SomeWorker 4 { 5 6 /** @var SessionInterface */ 7 private $session; 8 9 /** @var SessionInterface $session */ 10 public function __construct(SessionInterface $session) 11 { 12 $this->session = $session; 13 } 14 15 public function run() 16 { 17 var_dump($this->session); 18 fwrite(STDERR, var_export($this->session, true)); 19 $this->session->put('foo'); 20 $this->session->put('bar'); 21 } 22 23 } CONTROL INSPECTION MODIFICATION
8. <?phpeople ?> 1 <?php 2 3 class SomeWorker 4 { 5 6 /** @var SessionInterface */ 7 private $session; 8 9 /** @var SessionInterface $session */ 10 public function __construct(SessionInterface $session) 11 { 12 /* Using a stubbed session for debugging purposes 13 * @todo Remove before commit! 14 $this->session = $session; 15 */ 16 $this->session = new Session(); 17 $this->session->setUsername('john@example.com'); 18 } 19 20 public function run() 21 { 22 $this->session->put('foo'); 23 $this->session->put('bar'); 24 } 25 26 } CONTROL INSPECTION MODIFICATION
9. <?phpeople ?> "(…) check for common oversights like var_dump(), die() or console.log() (…)"
10. <?phpeople ?> Derick Rethans
11. <?phpeople ?> Derick Rethans
12. <?phpeople ?> Xdebug extension
13. <?phpeople ?> initial release in 2002
14. <?phpeople ?> code coverage $ phpunit PHPUnit 4.7.3 by Sebastian Bergmann and contributors. Runtime: PHP 5.5.9-1ubuntu4.9 with Xdebug 2.2.3 Configuration: /vagrant/dev/datapool/phpunit.xml.dist ............................................................... 63 / 286 ( 22%) ............................................................... 126 / 286 ( 44%) ............................................................... 189 / 286 ( 66%) ............................................................... 252 / 286 ( 88%) .................................. Time: 7.44 seconds, Memory: 31.50Mb OK (286 tests, 581 assertions) Generating code coverage report in Clover XML format ... done Generating code coverage report in HTML format ... done
15. <?phpeople ?> code coverage in PHPUnit $ phpunit PHPUnit 4.7.3 by Sebastian Bergmann and contributors. Runtime: PHP 5.5.9-1ubuntu4.9 Configuration: /vagrant/dev/datapool/phpunit.xml.dist ............................................................... 63 / 286 ( 22%) ............................................................... 126 / 286 ( 44%) ............................................................... 189 / 286 ( 66%) ............................................................... 252 / 286 ( 88%) .................................. Time: 7.44 seconds, Memory: 31.50Mb OK (286 tests, 581 assertions) with Xdebug 2.2.3 Generating code coverage report in Clover XML format ... done Generating code coverage report in HTML format ... done
16. <?phpeople ?> code coverage in PHPUnit
17. <?phpeople ?> code coverage in PHPUnit $ phpunit PHPUnit 4.7.3 by Sebastian Bergmann and contributors. Runtime: PHP 5.5.9-1ubuntu4.9 Configuration: /vagrant/dev/datapool/phpunit.xml.dist Warning: The Xdebug extension is not loaded No code coverage will be generated. ............................................................... 63 / 286 ( 22%) ............................................................... 126 / 286 ( 44%) ............................................................... 189 / 286 ( 66%) ............................................................... 252 / 286 ( 88%) .................................. Time: 7.44 seconds, Memory: 31.50Mb OK (286 tests, 581 assertions)
18. <?phpeople ?> improved stack traces
19. <?phpeople ?> XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_JMP); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_JMPZ); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_JMPZ_EX); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_JMPNZ); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_IS_IDENTICAL); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_IS_NOT_IDENTICAL); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_IS_EQUAL); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_IS_NOT_EQUAL); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_IS_SMALLER); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_IS_SMALLER_OR_EQUAL); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_BOOL_NOT); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_ADD); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_SUB); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_MUL); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_DIV); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_ADD_ARRAY_ELEMENT); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_RETURN); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_RETURN_BY_REF); XDEBUG_SET_OPCODE_OVERRIDE_COMMON(ZEND_EXT_STMT); opcode overloading https://github.com/xdebug/xdebug/blob/master/xdebug.c
20. <?phpeople ?> configuring Xdebug for debugging
21. <?phpeople ?> DBGP for remote debugging Animation taken from http://www.xdebug.org/docs/remote
22. <?phpeople ?> no fixed remote IP needed since Xdebug 2.1 Animation taken from http://www.xdebug.org/docs/remote
23. <?phpeople ?> phpdbg SAPI
24. <?phpeople ?> integrated into PHP 5.6+ https://secure.php.net/supported-versions.php
25. <?phpeople ?> debugging from the command line
26. <?phpeople ?> can show compiled bytecode
27. <?phpeople ?> no IDE integration :( https://github.com/krakjoe/phpdbg/issues/105
28. <?phpeople ?> Demo Time!
29. <?phpeople ?> @belanur https://github.com/belanur/php-debug-vm sebastian@phpeople.de sebastian@phpeople.de THANK YOU!