Practical Refactoring Tips For Developers That Love Legacy Applications 2017-08-17 @ Nomad PHP Davi Marcondes Moreira - @devdrops 

Agenda ➔ Intro ➔ Why worry about refactoring? ➔ Practical tips! ➔ The most important tip - of all!!! 

Agenda ➔ Intro ➔ Why worry about refactoring? ➔ Practical tips! ➔ The most important tip - of all!!! Trust me, it’s really the most important! :D 

Intro Hi! I’m Davi Marcondes Moreira I’m a software developer at Pagar.me (Sao Paulo, Brazil). ~8 years PHP and (now struggling with) Node.js. Refactor enthusiast (mending is awesome!). I love dogs/cats/a bunch of other stuff! 

Why worry about refactoring? Makers vs Menders Creating is awesome, but fixing is where I find my true passion. 

Why worry about refactoring? Makers vs Menders Creating is awesome, but fixing is where I find my true passion. Broken Window Theory Software maintenance is critical for all business. 

Practical tips! Where do I begin? Or, how to cure a sickness? 

Practical tips! Where do I begin? Or, how to cure a sickness? With a proper diagnosis :P 

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Practical tips! 1. Renaming methods Using a clearer and more descriptive declaration. Be explicit as possible. In critical situations, you can insert the new call inside the old one; so you can keep changing without breaking any compatibility in your code base. 

Practical tips! // Class spread all over your app class Foo { public function oldScaryMethod( $foo, $bar, $baz ) { // Lots of things happening here } } 

Practical tips! // Class spread all over your app class Foo { public function oldScaryMethod( $foo, $bar, $baz ) { // Lots of things happening here } } // Call encapsulated in another method class Foo { public function newMethod( $foo ) { // We can act here $this->oldScaryMethod(...); } public function oldScaryMethod(...) { // Complexity is now isolated! } } 

Practical tips! 2. Extracting responsabilities Single Responsability Principle Identify where you can move extra responsabilities found in your code into new classes/methods. 

Practical tips! 3. Remove dead code Copied-and-pasted or commented code: seek and destroy. Don’t be affraid to delete code - use your VCS and relax. Remember to always have a good test strategy to make sure that things aren’t left broken. 

The most important tip - of all!! Is the Intention! Encourage your team by cultivating a good culture of refactoring, involving tests, boldness, and empowerment. Don’t be negligent: the problem you neglect today will become the bug you will fix tomorrow - or 10 minutes after deploying. 

Thank you! :D @devdrops devdrops.me/about