go-type-code

It is a repository to explain how to apply the pattern "Replace Type Code with Class Struct" from book Refactoring To Patterns written by Joshua Kerievsky over Go language

What's type code? The constants that you have to specify number/ strings with understandable names.

Problem

A STRUCT has a field that contains type code. The values of this type aren't used in operator conditions and don’t affect the behavior of the program.

|         Payment        |
|------------------------|
| status          string |
| StatusInitial   string |
| StatusWaiting   string |
| StatusPaid      string |
| StatusCancelled string |

Solution

Create a new STRUCT and use its instance instead of the type code values.

Solution with STRING

|    Payment    |     |       Status     |     
|---------------|  -> |------------------|
| status Status |     | Initial   string |
                      | Cancelled string |
                      | Paid      string |
                      | Waiting   string |

Solution with INT (using IOTA)

|    Payment    |     |     Status    |     
|---------------|  -> |---------------|
| status Status |     | Initial   int |
                      | Cancelled int |
                      | Paid      int |
                      | Waiting   int |