Upcase Refactoring Trail

Replace Variable with Query

Refactoring exercise using the Replace Temp with Query refactoring for the Upcase Refactoring Trail.

Replace Temp with Query

Extract the expression into a method. Replace all references to the temp with the expression. The new method can then be used in other methods. -- Martin Fowler

Before

classTipper
...
deftotaltax_amount=amount * TAXdiscount_amount=amount * (discount_percentage / 100.0)tip_amount=amount * (tip_percentage / 100.0)amount + tax_amount - discount_amount + tip_amountendend

After

classTipper
...
deftotalamount + tax_amount - discount_amount + tip_amountendprivatedeftax_amountamount * TAXenddefdiscount_amountamount * (discount_percentage / 100.0)enddeftip_amountamount * (tip_percentage / 100.0)endend

Additional Resources

• Ruby Patterns: Query Method by Rein Henrichs