Fighting Ruby code smell

Fighting Code Smell with RubyMine Dennis Ushakov Oleg Shpynov www.jetbrains.com

Goals of this workshop• Show available code quality tools• How do they work• Show what RubyMine can offer www.jetbrains.com 2

Working with code 20% Write new code 80% Modify existing code: bugfixes, optimizations, etc. www.jetbrains.com 3

Code quality tools Reek Flay Flog Roodi Dust Heckle Metrics_fu RSpec Cucumber Autotest RCov SimpleCov www.jetbrains.com 4

Code quality tools• Static• Runtime www.jetbrains.com 5

Static tools• Inspect your code without launching it•100% side effects free•Easy to use•Challenging to implement•Rails DSL magic kills ‘em•Ruby has no formal specification www.jetbrains.com 6

Runtime tools• Inspect your code by launching it•100% follow the way Ruby works•Cope well with Rails DSL•MAY have side effects•Works until the very first failure www.jetbrains.com 7

Code that smells• Runtime errors• Runtime warnings (like parens in calls etc.)• Dead code• Copy/paste• Complex method bodies• Code style violations (i.e. naming conventions, etc)• Framework pattern violations (MVC pattern violations) www.jetbrains.com 8

Metrics• Reek – Uncommunicative name – One char name – Name ends with number – Camelcase variable – instance_of?, kind_of?, is_a? instead of polymorphism – Duplication – Long class, method, parameter list – Nested iterators www.jetbrains.com 9

Metrics• Flog – Assignment Branch Call metrics• Saikuro – Cyclomatic complexity• Roodi – Assignment in condition – Missing else in case – Long class/module/method – Class/module/method name check – Cyclomatic complexity• Flay – Duplicates www.jetbrains.com 10

Testing and Coverage tools• RSpec• Cucumber• Autotest• RCov, SimpleCov• Continuous integration• Heckle – Change code (if <-> unless, calls, numbers, assignments, etc.) to see if test fail www.jetbrains.com 11

Practicewww.jetbrains.com 12

What else can be done?All these tools use Abstract Syntax Tree, but this is not all the information that can be extracted!The main problem is Ruby object model complexityLEXICAL analysis• Lexer -> Parser -> Abstract Syntax Tree -> Control Flow Graph -> Data Flow Analysis www.jetbrains.com 13

RubyMine• On the fly code inspections• Code duplicates• Test tools integration with graphical UI• Coverage tool integration• Everything is tightly integrated in IDE www.jetbrains.com 14

GO AND TRY!jetbrains.com/ruby www.jetbrains.com 15

Thank you!• Visit us http://www.jetbrains.com/ruby• Read about http://blogs.jetbrains.com/ruby/• Post bugs http://youtrack.jetbrains.net/issues/RUBY• Follow us on twitter @rubymine www.jetbrains.com 16

Develop with pleasure!Dennis.Ushakov@jetbrains.com @en_dalOleg.Shpynov@jetbrains.com @oleg_s www.jetbrains.com Copyrights are retained by their respective owners

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Fighting Ruby code smell

by olegshpynov on Oct 16, 2011

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Fighting Ruby code smell — Presentation Transcript