Refactoring Long Methods

Marc Ignaciotwitter: @pd_igithub: @padi

Refactoring

RefactoringLong Methods

Definitions

Refactoring

● “…is a disciplined technique for restructuring an existing body of code, altering its internal structure without changing its external behavior.”

- refactoring.com

Refactoring

● “…is a disciplined technique for restructuring an existing body of code, altering its internal structure without changing its external behavior.”

- refactoring.com

Refactoring

● “…is a disciplined technique for restructuring an existing body of code, altering its internal structure without changing its external behavior.”

- refactoring.com

Refactoring

● “…is a disciplined technique for restructuring an existing body of code, altering its internal structure without changing its external behavior.”

- refactoring.com● “Tests are implied.” - Katrina Owen

Refactoring

● “…is a disciplined technique for restructuring an existing body of code, altering its internal structure without changing its external behavior.”

- refactoring.com

Refactoring

a technique for restructuring code without changing

behavior

Refactoring

a technique for making code suck less without changing

behavior

Refactoring

Long Methods

● “a method, function, or procedure that has grown too large”

Long Methods

● “a method, function, or procedure that has grown too large”

Long Methods

● “a method, function, or procedure that has grown too large”

● IMO: a method with a flog score of > 20

Long Methods

● ruby gem for analyzing code pain● “Flog reports the most tortured code in an

easy to read pain report.”● “The higher the score, the more pain the

code is in.”

Flog

Flog Scores● 0-10 Awesome● 11-20 Good enough● 21-40 Might need refactoring● 41-60 Possible to justify● 61-100 Danger● 100-200 Whoop, whoop, whoop● 200 + Someone please think of the children

Long Methods● If a method is long, it’s likely that it does too

many things.● “Methods, like classes, should have single

responsibility.” - Sandi Metz● SRP - every class should have a single

responsibility, and that responsibility should be entirely encapsulated by the class

Techniques

● Extract Method● Inline Method● Inline Temp● Replace Temp with Query● Replace Method w/ Method Object

Techniques

Examples

Resources

Resources- "Refactoring: Improving the Design of Existing Code", Martin Fowler- refactoring.com- jakescruggs.blogspot.com/2008/08/

whats-good-flog-score.html

Code:- "Refactoring, Ruby Edition", Martin Fowler et al.- "Therapeutic Refactoring", Katrina Owens

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Questions?

Thanks!