9. Dragon ADR Damage Make

  • ADR - Architecture Design Records

9.1. Problem

  • Dragon makes damage

9.2. Option 1

>>> dragon.get_damage()

  • Good: easy use

  • Good: readability

  • Good: clear intent

  • Good: easy to add validation if needed

  • Bad: name get_damage() indicate a getter of damage attribute

  • Decision: rejected, bad method name

9.3. Option 2

>>> dragon.attack()  # dragon  -> enemy
>>> dragon.hit()     # dragon <-> enemy
>>> dragon.hurt()    # dragon <-  enemy
>>> dragon.damage()  # dragon <-  enemy
>>> dragon.wound()   # dragon <-  enemy

  • Bad: Indication of direction is too weak dragon <-> enemy

  • Bad: not directed, all methods could mean making damage or receiving damage

  • Decision: rejected, bad method names

Rationale:

Some method names has stronger emphasis on who is making damage to whom. Consider this: dragon.hurt() - is that dragon who makes damage or takes damage?

dragon --> enemy
dragon  -> enemy
dragon <-> enemy
dragon <-  enemy
dragon <-- enemy

9.4. Option 3

>>> dragon.take_damage()    # dragon <-- enemy

  • Good: Simple

  • Bad: Relation is other way around dragon <-- enemy

  • Decision: rejected, relation is other way around

9.5. Option 4

>>> dragon.deal_damage()    # dragon --> enemy
>>> dragon.hurt_someone()   # dragon --> enemy

  • Good: Strong indication of direction dragon --> enemy

  • Bad: hurt_someone() method name is too use-case specific

  • Decision: rejected, method names are too use-case specific

9.6. Option 5

>>> dragon.make_damage()    # dragon --> enemy

  • Good: Strong indication of direction dragon --> enemy

  • Good: Name indicates intent

  • Decision: candidate

9.7. Option 6

>>> dragon.damage(ENEMY)
>>> dragon.attack(ENEMY)
>>> dragon.hit(ENEMY)
>>> dragon.wound(ENEMY)
>>> dragon.make_damage(ENEMY)
>>> dragon.take_damage(ENEMY)

  • Bad: violates Model-View-Controller (MVC)

  • Bad: each ENEMY will get different (random) damage

  • Decision: rejected, violates Model-View-Controller (MVC)

../_images/dragon-firkraag-01.jpg
../_images/oop-architecture-mvc.png
../_images/oop-architecture-mvc-example.png

Problem:

>>> class BankAccount:
...     def transfer(destination_account, amount):
...         self.withdraw(amount)
...         destination_account.deposit(amount)

  • Bad: this is not how bank transfers are done (especially between banks)

  • Bad: other bank of will not share their source code with you, to make a transfer

9.8. Option 7

>>> hero.health -= dragon.damage()

  • Good: simple

  • Good: can use @property for validation if needed

  • Bad: violates encapsulation

  • Decision: rejected, violates encapsulation

9.9. Option 8

>>> hero.wound(dragon.hit())

  • Bad: readability

  • Bad: requires knowledge of API

  • Bad: this is responsibility of a controller

  • Decision: rejected, violates Model-View-Controller (MVC)

9.10. Decision

>>> dmg = dragon.make_damage()

  • Good: clear intent

  • Good: dragon <-- enemy

  • Good: readability

  • Good: encapsulation