Refactoring Day 6 : Push Down Field

Opposite of the Pull Up Field refactoring is push down field. Again, this is a pretty straight forward refactoring without much description needed

   1: public abstract class Task

   2: {

   3:     protected string _resolution;

   4: }

   5:  

   6: public class BugTask : Task

   7: {

   8: }

   9:  

  10: public class FeatureTask : Task

  11: {

  12: }

In this example, we have a string field that is only used by one derived class, and thus can be pushed down as no other classes are using it. It’s important to do this refactoring at the moment the base field is no longer used by other derived classes. The longer it sits the more prone it is for someone to simply not touch the field and leave it be.

   1: public abstract class Task

   2: {

   3: }

   4:  

   5: public class BugTask : Task

   6: {

   7:     private string _resolution;

   8: }

   9:  

  10: public class FeatureTask : Task

  11: {

  12: }

This is part of the 31 Days of Refactoring series. For a full list of Refactorings please see the original introductory post.