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flyerhzm
September 19, 2014
Programming
3.8k
5
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Write ruby code to change ruby code
flyerhzm
September 19, 2014
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Transcript
Write ruby code to change ruby code Richard Huang Xinmin
Labs
About Me Founder at Xinmin Labs Full Stack Developer Open
Source Enthusiast @flyerhzm
Problem
Hey, let’s use rspec new syntax for project A Yes,
sure, I love the rspec new syntax
Hey, let’s use rspec new syntax for project B Hmmm…ok
Hey, let’s use rspec new syntax for project C Oh,
no, I don’t want to repeat it again
Developers love upgrading and refactoring code
Developers hate changing code again and again
Automation
Metric Tools
Metric Tools • cane - fails your build if code
quality thresholds are not met • reek - is a tool that examines Ruby classes, modules and methods and reports any code smells it finds. • rails_best_practices - is a tool to check the quality of rails code. • ……
Tell you what to do, but can’t do for you
IDE
IDE • can rename class / method / variable name
• can extract methods • can ……
IDE • can’t customize
Based on text
Based on text Replace FactoryGirl.create with create ! $ sed
-i '' 's/FactoryGirl.create/create/g' spec/**/*.rb
Based on text Replace FactoryGirl.create with create ! !
Based on text Hard to be accurate ! ! !
!
Based on text Hard to convert complicated cases ! !
! !
Based on AST
What’s AST AST is short for Abstract Syntax Tree
What’s AST
Why AST It is much more accurate to parse ruby
code.
None
None
How to use AST • ripper • ParseTree - https://github.com/seattlerb/parsetree
• ruby_parser - https://github.com/seattlerb/ruby_parser • parser - https://github.com/whitequark/parser
How to use AST
Example transpec - https://github.com/yujinakayama/ transpec
None
Based on AST Accurate, but hard to write and read
Synvert https://github.com/xinminlabs/synvert
Demo http://xinminlabs.github.io/synvert/
None
Synvert • Add useful attributes to AST nodes ! •
Provide DSL to parse and rewrite code
Attributes for AST node
Attributes for AST node
Attributes for AST node
Attributes for AST node Check out more attributes http://xinminlabs.github.io/synvert/rules/
DSL • within_file / within_files • with_node / within_node •
if_exist_node / unless_exist_node • append / insert / insert_after / replace_with / remove • ……
DSL Check out more DSL http://xinminlabs.github.io/synvert/dsl/
None
Playground http://synvert-tools.herokuapp.com/
Snippets https://github.com/xinminlabs/synvert-snippets
Want more? • Fork and send pull request • Open
issues on github • Hire us to refactor your project
Q&A ! Thank you