Refactoring Rails applications with RubyMine

Refactoring Rails apps with RubyMine

Andrzej Krzywda Arkency

Andrzej Krzywda

• Arkency

• Rails since 2004

• hundreds of Rails projects reviewed

Agenda

• Typical Rails problems

• Beyond The Rails Way - new patterns

• Refactoring recipes with RubyMine

Rails is great• In the first month of development

• Quick results in almost no code

• Quick feedback loop

• Predictable speed

• Your customer loves you

• You love Rails

2.months.later

Typical Rails problems

• MVC is not enough

• first regression bugs

• slow tests

• slower progress

6.months.later

Typical Rails problems

• hidden dependencies

• implicit assumptions (aka Convention over Configuration)

• security bugs!

• Rails upgrades are now projects on their own with (huge) budgets

2.years.later

Typical Rails problems

Any questions so far?

New guidelines

• explicit > implicit

• reducing meta

• more building blocks

New patterns

• Inspired by:

• DDD

• Hexagonal Architecture

• DCI

• CQRS/Event Sourcing

The building blocks• Service objects

• Repositories

• Adapters

• Form objects

• Domain objects

• RubyMine

Extract a service object

• the gateway drug

• a training in refactoring

• turn a controller action into a method object

Questions?

Typical controller coupling• new-action uses the ‘new’ view

• create-action uses the ‘new’ view

• edit-action uses the ‘new’ view

• ‘new’ view uses _form partial

• ‘edit’ view uses _form partial

• ‘edit’ action uses ‘edit’ view

• ‘update’ action uses ‘edit’ view

newcreate

edit

update

new.haml

edit.haml_form.haml

show.rsb

common/error_messages.rsb

The filters algebra

• Filters depending on each other

• The order is important

• Hard to decouple

• communication via @ivars

At the controllers/views level everything is communicating

with each other via @ivars

Everything is depending on instance variables

Controller instance variables are the global,

mutable state

the Redmine project• a project management tool

• contains a time-tracking module

• http://www.redmine.org/projects/redmine/wiki/RedmineTimeTracking

• since 2007

• https://github.com/redmine/redmine

RubyMine coding

• look at the existing concerns

• run the subset of tests

• keep refactoring

Summary

• Typical Rails problems

• Refactoring example

• RubyMine support

• http://rails-refactoring.com/recipes/

Fearless Refactoring: Rails

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Questions?