Pry: Tips, Tricks, How To

Transcript

1. TIPS, TRIC KS, HOW TO A M Y D U S E K
2. WHOAMI • Amy Dusek
3. Home of the famous “Florida Man”
4. QUARTER-LIFE CRISIS
5. CURRENTLY A DEVELOPER @ An Electronic Medical Records Software aimed at Substance Abuse facilities
6. SO…WHAT IS PRY AND WHY SHOULD I CARE? • The WHAT: – Ruby Gem – A well known alternative to the standard IRB shell for Ruby – A runtime developer console for Ruby • The WHY SHOULD I CARE? – Because you’re at a talk about Pry – Also, it’s a powerful tool for debugging
7. DEBUGGING CAN SOMETIMES FEEL LIKE …
8. PRY CAN HELP • Pry is your friend! • Debugging is a huge part of our job as Developers – Developers spend 60% of their time debugging – The faster we can debug, the faster we can get back to Reddit! • Many are familiar with ‘binding.pry’ but don’t use Pry to its potential – This method starts a Pry session and pauses the code execution – Think of it as opening the Rails console (at a chosen point in the execution path)
9. GETTING STARTED: INSTALLING PRY (IF YOU HAVEN’T OR JUST WANT TO AGAIN FOR FUN) • $ gem install pry
10. LET’S EXPLORE!! • Start a Pry Session – $ pry
11. RUN SHELL COMMANDS • Preface your commands with a period • Examples – . git status – . git diff – . curl http://www.google.com – . cat file.rb
12. INPUT BUFFER • ! – Clears the input buffer – Breaks out of the read loop -- doing this will enable normal input to resume on the next line. • show-input – Useful when entering long multi-line expressions • amend-line – amend-line line# – amend-line line#range • edit – edit class/method/etc • Opens temp pry file in default editor
13. MORE ON EDIT • When you run edit inside a pry window, it opens up a temporary file for editing. • The editor of choice can be configured in the ~/.pryrc with the directive Pry.config.editor = 'vim'. • Once you save the file and close it, it gets run by the pry session and you can access whatever elements you define inside of it. • How to use it: – edit sample.rb # Specific file – edit sample.rb --line 105 # Specific line – edit MyClass # Edit by class – edit MyClass#my_method # Specific method – edit --ex # Edit the file that raised the most recent exception
14. RUN RUBY CODE WITH PRY • Instead of: – ruby awesome_code.rb • Use: – pry awesome_code.rb • Will even start an interactive session if an exception is encountered!
15. CD & LS • Navigate objects like you would directories in your terminal • How to: – cd Object – cd .. – ls • Lists out methods available to the current scope and other useful info • -i flag will list out instance variables if any
16. WTF • Shows you the most recently thrown exception • Appeals to the anger or confusion you feel when an Exception is thrown
17. NESTING • Displays more information about nesting • jump-to – Jumps back to any of the previous nesting levels. – Inception problems solved!
18. WHEREAMI • For when you’re confused/forgot you can use the nesting command
19. PLAY LINES • play –l – Can run specific lines of code or ranges of lines of code • Example: – Place a binding.pry somewhere in your code – Can now play subsequent lines of code
20. SHOW-DOC • Alias: ? • Example – ? Array#map – ? binding – ? Pry
21. SHOW-SOURCE • Alias: $ • Examples – $ Array#map – $ binding – $ Pry
22. RESOURCES • We’ve barely scratched the surface – Pry is highly configurable – Many helpful plugins you can use in tandem to level up your debugging skills • Resources: – Pry wiki: https://github.com/pry/pry/wiki – Pry docs: http://www.rubydoc.info/github/pry/pry/master/Pry – Available Pry Plugins: https://github.com/pry/pry/wiki/Available-plugins