The debug dance: An intro to step debugging - ZendCon & OpenEnterprise 2018

Talk given at ZendCon & OpenEnterprise (2018-10-16)

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.

Transcript

1. joind.in/talk/5fb02
   @SammyK #zcoe18
   Sammy Kaye Powers
   Dance
   The
   Las Vegas, NV - 2018
   An Intro To
   Step Debugging in
   

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2. joind.in/talk/5fb02
   @SammyK #zcoe18
   Download the
   slides
   joind.in/talk/5fb02
   

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3. joind.in/talk/5fb02
   @SammyK #zcoe18
   Does not work for
   

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4. joind.in/talk/5fb02
   @SammyK #zcoe18
   What is
   Debugging?
   Finding and fixing unexpected behavior in code
   

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5. So you write
   Some Code
   

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6. Does not work
   

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7. joind.in/talk/5fb02
   @SammyK #zcoe18
   You could check the
   Error logs
   

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8. joind.in/talk/5fb02
   @SammyK #zcoe18
   All the things
   var_dump()
   

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9. joind.in/talk/5fb02
   @SammyK #zcoe18
   

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10. joind.in/talk/5fb02
    @SammyK #zcoe18
    OR
    

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11. joind.in/talk/5fb02
    @SammyK #zcoe18
    Use a
    ‘er
    

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12. joind.in/talk/5fb02
    @SammyK #zcoe18
    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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13. joind.in/talk/5fb02
    @SammyK #zcoe18
    …now is the perfect time to learn
    Step Debugging
    BNEW!
    Professional
    

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14. joind.in/talk/5fb02
    @SammyK #zcoe18
    Some step-debugging
    Jargon
    

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15. joind.in/talk/5fb02
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    a signal that tells the debugger to pause the execution of your code
    Breakpoint
    

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16. joind.in/talk/5fb02
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    run to the next breakpoint
    Resume Program
    

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17. joind.in/talk/5fb02
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    advance to the next line in the same scope
    Step Over
    

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18. joind.in/talk/5fb02
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    if the next line is a function call, enter the function
    Step Into
    

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19. joind.in/talk/5fb02
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    run to the end of the current function
    Step Out
    

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20. joind.in/talk/5fb02
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    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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21. joind.in/talk/5fb02
    @SammyK #zcoe18
    &
    Environment
    Setup
    

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22. joind.in/talk/5fb02
    @SammyK #zcoe18
    

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23. joind.in/talk/5fb02
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    https://xdebug.org/docs/remote
    Debug client (DBGp protocol)
    

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24. joind.in/talk/5fb02
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    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/5fb02
    @SammyK #zcoe18
    Done!
    

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28. joind.in/talk/5fb02
    @SammyK #zcoe18
    Setup
    

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29. configured
    installed
    installed
    

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30. on
    Homebrew
    Install +
    $ brew install php
    $ pecl install xdebug
    

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31. on
    APT
    Install +
    $ add-apt-repository -y \
    ppa:ondrej/php
    $ apt-get update
    $ apt-get install php7.2-xdebug
    

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

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34. joind.in/talk/5fb02
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    Configure
    

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35. $ php --ini
    

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36. $ php --ini
    

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37. $ sudo vi /usr/local/etc/php/
    7.2/conf.d/ext-xdebug.ini
    

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38. $ php -i | grep xdebug
    

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39. joind.in/talk/5fb02
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    Start a session
    or
    CLI
    

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40. joind.in/talk/5fb02
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    Query Param
    XDEBUG_SESSION_START
    

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41. joind.in/talk/5fb02
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    Cookie
    XDEBUG_SESSION
    

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42. joind.in/talk/5fb02
    @SammyK #zcoe18
    

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43. joind.in/talk/5fb02
    @SammyK #zcoe18
    

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44. joind.in/talk/5fb02
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    Env Variable
    export XDEBUG_CONFIG="idekey=foo"
    CLI
    

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45. joind.in/talk/5fb02
    @SammyK #zcoe18
    Env Variable
    set XDEBUG_CONFIG="idekey=foo"
    CLI
    

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46. joind.in/talk/5fb02
    @SammyK #zcoe18
    Don’t forget to unset
    set XDEBUG_CONFIG=
    unset XDEBUG_CONFIG
    when you’re done
    

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47. joind.in/talk/5fb02
    @SammyK #zcoe18
    alias debug-on='export
    XDEBUG_CONFIG="ide_key=foo"'
    alias debug-off='unset
    XDEBUG_CONFIG'
    Bash alias
    

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48. joind.in/talk/5fb02
    @SammyK #zcoe18
    Run some code!
    &
    CLI
    

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49. joind.in/talk/5fb02
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    PHP’s Built-in
    Web Server
    run locally using
    

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50. joind.in/talk/5fb02
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    Built right into the CLI SAPI!
    $ php -S 127.0.0.1:8888
    

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51. joind.in/talk/5fb02
    @SammyK #zcoe18
    

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52. joind.in/talk/5fb02
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    learn?
    What did we
    

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53. joind.in/talk/5fb02
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    +
    

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54. joind.in/talk/5fb02
    @SammyK #zcoe18
    

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55. joind.in/talk/5fb02
    @SammyK #zcoe18
    

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56. joind.in/talk/5fb02
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    CLI
    

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57. joind.in/talk/5fb02
    @SammyK #zcoe18
    Debugging In Action
    

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58. joind.in/talk/5fb02
    @SammyK #zcoe18
    

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59. joind.in/talk/5fb02
    @SammyK #zcoe18
    In production
    

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60. But wait!
    * (see me after class for more info)
    

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61. Sammy Kaye Powers
    Thanks!
    /talk/5fb02
    @SammyK
    SammyK.me
    Host of @PHPRoundtable
    

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