How to write testable code

Transcript

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6. .
   public class Fight {
   private State state = new State();
   private Player player1, player2;
   public Fight(Player player1, Player player2) {
   this.player1 = player1;
   this.player2 = player2;
   }
   ...
   public void attack(Player attacker, Weapon weapon) {
   Player opponent = getOpponentOf(attacker);
   int damage = calculateDamage(opponent, weapon);
   opponent.setHp(opponent.getHp() - damage);
   Utility.updatePlayer(opponent);
   updateState();
   }
   public State getState() {
   return state;
   }
   ...
   }
   

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7. .
   public class FightTest {
   @Test
   public void testAttack() {
   Player player1 = new Player();
   Player player2 = new Player();
   Weapon weapon = new Weapon();
   Fight fight = new Fight(player1, player2);
   fight.attack(player1, weapon);
   fight.attack(player1, weapon);
   fight.attack(player1, weapon);
   State state = fight.getState();
   assertThat(state.isFinished(), is(true));
   }
   }
   

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8. 
   
   

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9. public class Fight {
   private State state = new State();
   private Player player1, player2;
   public Fight(Player player1, Player player2) {
   this.player1 = player1;
   this.player2 = player2;
   }
   ...
   public void attack(Player attacker, Weapon weapon) {
   Player opponent = getOpponentOf(attacker);
   int damage = calculateDamage(opponent, weapon);
   opponent.setHp(opponent.getHp() - damage);
   Utility.updatePlayer(opponent);
   updateState();
   }
   public State getState() {
   return state;
   }
   ...
   }
   .
   

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10. B
    . D
    public class Fight {
    private State state = new State();
    private Player player1, player2;
    public Fight(Player player1, Player player2) {
    this.player1 = player1;
    this.player2 = player2;
    }
    ...
    public void attack(Player attacker, Weapon weapon) {
    Player opponent = getOpponentOf(attacker);
    int damage = calculateDamage(opponent, weapon);
    opponent.setHp(opponent.getHp() - damage);
    Utility.updatePlayer(opponent);
    updateState();
    }
    public State getState() {
    return state;
    }
    ...
    }
    .
    

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11. public class Fight {
    private State state = new State();
    private Player player1, player2;
    public Fight(Player player1, Player player2) {
    this.player1 = player1;
    this.player2 = player2;
    }
    ...
    public void attack(Player attacker, Weapon weapon) {
    Player opponent = getOpponentOf(attacker);
    int damage = calculateDamage(opponent, weapon);
    opponent.setHp(opponent.getHp() - damage);
    Utility.updatePlayer(opponent);
    updateState();
    }
    public State getState() {
    return state;
    }
    ...
    }
    .
    

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12. 2 .
    

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13. •
    

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15. ()
    
    
    
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16. F
    .
    interface PlayerUpdater {
    public void updatePlayer(Player player);
    }
    F
    

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17. public class PlayerUpdaterImpl implements PlayerUpdater {
    @Override
    public void updatePlayer(Player player) {
    Utility.updatePlayer(player);
    }
    }
    .
    

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18. B
    .
    public class Fight {
    private State state = new State();
    private Player player1, player2;
    private final PlayerUpdater updater;
    public Fight(Player player1, Player player2) {
    this(player1, player2, new PlayerUpdaterImpl());
    }
    protected Fight(Player player1, Player player2,
    PlayerUpdater updater) {
    this.player1 = player1;
    this.player2 = player2;
    this.updater = updater;
    }
    ...
    public void attack(Player attacker, Weapon weapon) {
    Player opponent = getOpponentOf(attacker);
    int damage = calculateDamage(opponent, weapon);
    opponent.setHealth(opponent.getHealth() - damage);
    updater.updatePlayer(opponent);
    updateState();
    }
    }
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19. P
    . ( (
    public class Fight {
    private State state = new State();
    private Player player1, player2;
    private final PlayerUpdater updater;
    public Fight(Player player1, Player player2) {
    this(player1, player2, new PlayerUpdaterImpl());
    }
    protected Fight(Player player1, Player player2,
    PlayerUpdater updater) {
    this.player1 = player1;
    this.player2 = player2;
    this.updater = updater;
    }
    ...
    public void attack(Player attacker, Weapon weapon) {
    Player opponent = getOpponentOf(attacker);
    int damage = calculateDamage(opponent, weapon);
    opponent.setHealth(opponent.getHealth() - damage);
    updater.updatePlayer(opponent);
    updateState();
    }
    }
    ) ) .
    I U B D
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20. import static org.mockito.Mockito.*;
    public class FightTest {
    @Test
    public void testAttack() {
    Player player1 = new Player();
    Player player2 = new Player();
    Weapon weapon = new Weapon();
    // PlayerUpdater
    PlayerUpdater updater = mock(PlayerUpdater.class);
    // Fight
    Fight fight = new Fight(player1, player2, updater);
    fight.registerHit(player1, weapon);
    fight.registerHit(player1, weapon);
    fight.registerHit(player1, weapon);
    State state = fight.getState();
    assertThat(state.isFinished(), is(true));
    // updatePlayer() 3
    
    verify(updater, times(3)).updatePlayer(player2);
    }
    }
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