more strict checking for Scan for enum

[kontango-bot]

I think it could be nice to check for the actual values in the generated Scan method:

this is the default:

type EnumType string

const (
	EnumTypeSuccess EnumType = "success"
	EnumTypeFailure EnumType = "success"
)


func (e *EnumType) Scan(src interface{}) error {
	switch s := src.(type) {
	case []byte:
		*e = EnumType(s)
	case string:
		*e = EnumType(s)
	default:
		return fmt.Errorf("unsupported scan type for EnumType: %T", src)
	}
	return nil
}

Could add something like:

type EnumType string

const (
	EnumTypeSuccess EnumType = "success"
	EnumTypeFailure EnumType = "success"
)

// convenience function for returning all possible values
func(e *EnumType) Values() []EnumType {
  return []EnumType{
      EnumTypeSuccess
      EnumTypeFailure
  }
}

func (e *EnumType) Scan(src interface{}) error {
	switch s := src.(type) {
	case []byte:
		*e = EnumType(s)
	case string:
		*e = EnumType(s)
		switch s {
		case "success"
			*e = EnumTypeSuccess
			// etc
		default:
			return fmt.Errorf("string %s is not a member of enum EnumType", s)
		}

	default:
		return fmt.Errorf("unsupported scan type for EnumType: %T", src)
	}
	return nil
}