The document discusses various programming concepts related to code quality, including issues like feature envy, primitive obsession, and inappropriate intimacy. It includes examples of code snippets and emphasizes principles such as the use of parameters and data types to improve software design. The overall focus seems to be on enhancing understanding and organization of code for better maintainability and clarity.

1. Red, green,
… what now?!
@kevinrutherford
@jjeffries1

2. Primitive Obsession
Feature Envy
Sim
ulated
Polym
orphism
Lazy Class
Temporary Field
Inappropriate Intimacy
ShotgunSurgery
Data Clump
Long
M
ethod
Large Class
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??? ???
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???
???
???
RefusedBequest

3. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Connascence of ...

4. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Connascence of ...

5. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Connascence of ...

6. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Connascence of ...

7. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Connascence of ...

8. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Connascence of ...

9. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Connascence of ...

10. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Connascence of ...

11. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Connascence of ...

12. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Connascence of ...

13. Scanning a
single item

15. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Test: Code:

16. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Test: Code:CoEO
scan()scan()

17. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Test: Code:
CoV
CoEO
scan()scan()
5050

18. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Test: Code:CoEO
CoM
scan()scan()
int
int
int

19. Checkout with
an empty basket

21. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Test: Code:
CoM
int
int
int
unitPrice = 50
unitPrice = 50
int
CoA

22. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Test: Code:
CoM
int
int
int

23. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Test: Code:

24. Different items
have different
prices

26. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Test: Code:
string string
CoM

27. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Test: Code:
string string
balance.add()
balance.add()
CoM
CoA

28. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Test: Code:
“A”“A”
string string
balance.add()
balance.add()
CoV
CoM
CoA

29. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Test: Code:
CoV
“A”“A”
3030
string string
balance.add()
balance.add()
CoV
CoM
CoA

30. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Test: Code:
“A”“A”
string string
balance.add()
balance.add()
CoV
CoM
CoA
Money, MoneyMoney, Money
CoP

31. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Test: Code:
string string
balance.add()
balance.add()
CoM
CoA
Money, MoneyMoney, Money
CoP

32. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Test: Code:
string string
CoM
Map Map
CoM

33. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Test: Code:

34. Recap

35. Scanning a
single item

37. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Scanning has no
effect on the balance
Both classes know
the price = 50

38. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Introduce
Parameter{

39. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Scanning has no
effect on the balance
Everyone knows we use
an int to represent money

40. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Write a test{

41. Checkout with
an empty basket

43. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Everyone knows we use
an int to represent money
Common test
setup

44. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Introduce @Before
block{

45. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Everyone knows we use
an int to represent money

46. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Introduce Money class{

47. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9

48. Different items
have different
prices

50. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
balance.add()
called twice
Strings used to
represent product
codes
Everyone depends
on “A”
Everyone knows
the price of “B”

51. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Introduce
Parameter{

52. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
balance.add()
called twice
Strings used to
represent product
codes
Everyone depends
on “A”
Constructor parameters
are indistinguishable

53. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Introduce
Parameter{

54. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
balance.add()
called twice
Strings used to
represent product
codes
Constructor parameters
are indistinguishable

55. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Introduce a Map of
names to prices{

56. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Strings used to
represent product
codes
Map used to represent
the price list

57. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Introduce
PriceList{

58. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9
Introduce
ProductCode{

59. Name
Type
Meaning
Algorithm
Position
Execution Order
Timing
Value
Identity
1
2
3
4
5
6
7
8
9

60. Red, green,
… what now?!
@kevinrutherford
@jjeffries1