Slides from a workshop I ran at CodeCraftConf 2016.

1. © XPSurgery.com 2016 @kevinrutherford
Love and Death
“To love is to suffer. To avoid suffering
one must not love. But then one
suffers from not loving. Therefore,
to love is to suffer; not to love is to
suffer; to suffer is to suffer. To be
happy is to love. To be happy,
then, is to suffer, but suffering
makes one unhappy. Therefore,
to be unhappy, one must love or
love to suffer or suffer from too
much happiness.
I hope you're getting this down.”
Love and Death, Woody Allen, 1975

2. © XPSurgery.com 2016 @kevinrutherford
@kevinrutherford @xpsurgery
http://silkandspinach.net http://xpsurgery.com

3. © XPSurgery.com 2016 @kevinrutherford
?

4. © XPSurgery.com 2016 @kevinrutherford
SOLID
Primitive Obsession
Feature Envy
Sim
ulated
Polym
orphism
Lazy Class
Temporary Field
Inappropriate
Intim
acy
ShotgunSurgery
Data Clump
Long
M
ethod
Large Class
???
??? ???
???
???
???
???
RefusedBequest

5. © XPSurgery.com 2016 @kevinrutherford
Refactoring algorithm:
1. Remove some coupling
2. Repeat

6. © XPSurgery.com 2016 @kevinrutherford
https://github.com/ xpsurgery / corner-shop

7. © XPSurgery.com 2016 @kevinrutherford
A B
C

8. © XPSurgery.com 2016 @kevinrutherford
Warehouse
Actions
Catalogue
Actions
Basket
Actions
User
Interface
Warehouse
Catalogue
Basket Filestore
Main

9. © XPSurgery.com 2016 @kevinrutherford
Connascence between two software elements
A and B means either:
1) some change to A would require B to be changed,
(or at least carefully checked), or
2) some change would require both A and B
to be changed together
in order to preserve overall correctness.

10. © XPSurgery.com 2016 @kevinrutherford
Warehouse
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Catalogue
Actions
Basket
Actions
User
Interface
Warehouse
Catalogue
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11. © XPSurgery.com 2016 @kevinrutherford
Warehouse
Actions
Warehouse
Connascence of Name
Connascence of Type

12. © XPSurgery.com 2016 @kevinrutherford
Degree
Reach
Type

13. © XPSurgery.com 2016 @kevinrutherford
expression ↔ expression 0
function ↔ function 1
object ↔ object 2
module ↔ module 3
process ↔ process 4
Reach

14. © XPSurgery.com 2016 @kevinrutherford
Name
Type
Convention
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Type

15. © XPSurgery.com 2016 @kevinrutherford
Refactoring algorithm:
1. Organise the code into top-level
encapsulation units
2. Map the connascence among them
3. Remove the worst
4. Recurse into each
encapsulation unit [optional]

16. © XPSurgery.com 2016 @kevinrutherford
?
@kevinrutherford
@xpsurgery
http://silkandspinach.net/tag/connascence
http://xpsurgery.com