The Debug Dance - An Intro to Step Debugging - php[tek] 2017

This talk was given at php[tek] 2017.

Using `var_dump()` to debug your app has its benefits, but there are more comprehensive and efficient ways to debug those particularly elusive bugs. Enter step debugging. We’ll be using the PhpStorm IDE to step through our PHP apps line by line and see how much more power step debugging gives us over the conventional `var_dump()` technique. We'll also touch on debugging from the command line. Learn to dance in PHP with step debugging.

Code examples: https://github.com/SammyK/debug-dance-php-tek-2017

Transcript

1. joind.in/talk/a2b9a
   @SammyK #phptek
   Sammy Kaye Powers
   Dance
   The
   May 26th, 2017
   PHP[TEK] 2017
   An Intro To
   Step Debugging in
   

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2. Thanks to our
   Sponsors!
   

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3. joind.in/talk/a2b9a
   @SammyK #phptek
   Download the
   examples & slides
   joind.in/talk/a2b9a
   

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4. joind.in/talk/a2b9a
   @SammyK #phptek
   Does not work for
   

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5. joind.in/talk/a2b9a
   @SammyK #phptek
   What is
   Debugging?
   Finding and fixing unexpected behavior in code
   

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6. So you write
   Some Code
   

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7. Does not work
   

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8. joind.in/talk/a2b9a
   @SammyK #phptek
   You could check the
   Error logs
   

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9. joind.in/talk/a2b9a
   @SammyK #phptek
   All the things
   var_dump()
   

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10. joind.in/talk/a2b9a
    @SammyK #phptek
    

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11. joind.in/talk/a2b9a
    @SammyK #phptek
    OR
    

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12. joind.in/talk/a2b9a
    @SammyK #phptek
    Use a
    ‘er
    

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13. joind.in/talk/a2b9a
    @SammyK #phptek
    Kate Gregory “ I'm not saying, ‘don't
    use printf()’, [...] but
    I think it's insane to
    use printf() on day
    one of learning C++.
    [...] I would first say
    use the debugger.
    Episode 30: Stop Teaching C
    (When Teaching C++)
    

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14. joind.in/talk/a2b9a
    @SammyK #phptek
    …now is the perfect time to learn
    Step Debugging
    BNEW!
    Professional
    

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15. joind.in/talk/a2b9a
    @SammyK #phptek
    Some step-debugging
    Jargon
    

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16. joind.in/talk/a2b9a
    @SammyK #phptek
    a signal that tells the debugger to pause the execution of your code
    Breakpoint
    

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17. joind.in/talk/a2b9a
    @SammyK #phptek
    run to the next breakpoint
    Resume Program
    

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18. joind.in/talk/a2b9a
    @SammyK #phptek
    advance to the next line in the same scope
    Step Over
    

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19. joind.in/talk/a2b9a
    @SammyK #phptek
    if the next line is a function call, enter the function
    Step Into
    

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20. joind.in/talk/a2b9a
    @SammyK #phptek
    run to the end of the current function
    Step Out
    

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21. joind.in/talk/a2b9a
    @SammyK #phptek
    a live portal into the code execution process
    Debugging Console
    

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22. joind.in/talk/a2b9a
    @SammyK #phptek
    shows the execution path to the point where the code was paused
    Frames
    I… don’t have a cool drawing for “frames”…
    

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23. joind.in/talk/a2b9a
    @SammyK #phptek
    &
    Environment
    Setup
    

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24. joind.in/talk/a2b9a
    @SammyK #phptek
    Setup
    

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25. #1
    Start listening to
    debugging connections
    

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26. #2
    Set a
    Breakpoint
    

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27. joind.in/talk/a2b9a
    @SammyK #phptek
    Done!
    

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28. joind.in/talk/a2b9a
    @SammyK #phptek
    Setup
    

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29. configured
    installed
    installed
    

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30. $ brew tap homebrew/homebrew-php
    $ brew install php71
    $ brew install php71-xdebug
    on
    Homebrew
    Install +
    

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31. $ add-apt-repository -y ppa:ondrej/php
    $ apt-get update
    $ apt-get install php7.1-xdebug
    on
    APT
    Install +
    

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32. https://xdebug.org/docs/install
    Install +
    

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34. joind.in/talk/a2b9a
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    Configure
    

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35. $ php --ini
    

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36. $ sudo vi /usr/local/etc/php/
    7.1/conf.d/ext-xdebug.ini
    

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37. $ php -i | grep xdebug
    

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38. joind.in/talk/a2b9a
    @SammyK #phptek
    Start a session
    or
    CLI
    

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39. joind.in/talk/a2b9a
    @SammyK #phptek
    Query Param
    XDEBUG_SESSION_START
    

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40. joind.in/talk/a2b9a
    @SammyK #phptek
    Cookie
    XDEBUG_SESSION
    

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41. joind.in/talk/a2b9a
    @SammyK #phptek
    

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42. joind.in/talk/a2b9a
    @SammyK #phptek
    

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43. joind.in/talk/a2b9a
    @SammyK #phptek
    Env Variable
    export XDEBUG_CONFIG="idekey=foo"
    CLI
    

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44. joind.in/talk/a2b9a
    @SammyK #phptek
    Env Variable
    set XDEBUG_CONFIG="idekey=foo"
    CLI
    

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45. joind.in/talk/a2b9a
    @SammyK #phptek
    Don’t forget to unset
    set XDEBUG_CONFIG=
    unset XDEBUG_CONFIG
    when you’re done
    

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46. joind.in/talk/a2b9a
    @SammyK #phptek
    Run some code!
    &
    CLI
    

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47. joind.in/talk/a2b9a
    @SammyK #phptek
    PHP’s Built-in
    Web Server
    run locally using
    

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48. joind.in/talk/a2b9a
    @SammyK #phptek
    Built right into the CLI SAPI!
    $ php -S 127.0.0.1:8888
    

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49. joind.in/talk/a2b9a
    @SammyK #phptek
    

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50. joind.in/talk/a2b9a
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    learn?
    What did we
    

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51. joind.in/talk/a2b9a
    @SammyK #phptek
    +
    

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52. joind.in/talk/a2b9a
    @SammyK #phptek
    

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53. joind.in/talk/a2b9a
    @SammyK #phptek
    

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54. joind.in/talk/a2b9a
    @SammyK #phptek
    CLI
    

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55. joind.in/talk/a2b9a
    @SammyK #phptek
    Debugging In Action
    

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56. joind.in/talk/a2b9a
    @SammyK #phptek
    

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57. joind.in/talk/a2b9a
    @SammyK #phptek
    In production
    

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58. But wait!
    I have examples of other setups!
    &
    * (see me after class for more info)
    

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59. THANKS!
    SAMMY KAYE POWERS
    @SammyK
    SammyK.me
    Host of @PHPRoundtable
    @ChiPHPUG
    West Coast Swing
    Hire me! :)
    /talk/a2b9a
    I have
    stickers!
    

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