Kerem Yildiz

domain.md

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+# Domain Model
+
+## Classes
+
+### Account (abstract)
+- Variables:
+    - `balance: double`
+    - `transactions: List<Transaction>`
+- Methods:
+    - `deposit(amount: double, date: LocalDate)`
+    - `withdraw(amount: double, date: LocalDate)`
+    - `getTransactions(): List<Transaction>`
+    - `getStatement(): List<String>`
+
+### CurrentAccount (extends Account)
+- Variables:  -
+- Methods: inherits everything from Account
+
+### SavingsAccount (extends Account)
+- Variables: -
+- Methods: inherits everything from Account
+
+### Transaction
+- Variables:
+    - `date: LocalDate`
+    - `amount: double`
+    - `resultingBalance: double`
+- Methods:
+    - `toString(): String`
+
+## Scenario
+
+1. A customer creates a `SavingsAccount`.
+2. The customer deposits €1000 on 13/08/2025.
+3. The customer deposits €2000 on 23/09/2025.
+4. The customer withdraws €1500 on 25/09/2025.
+5. The customer requests the account statement.
+
+## Output
+
+1. 25/09/2025 || 1500.00 || 1500.00
+2. 23/09/2025 || 2000.00 || 3000.00
+3. 13/08/2025 || 1000.00 || 1000.00
+
+
+# Class diagram
+
+```
+------------------
+|   Account      |  <<abstract>>
+------------------
+| - balance: double
+| - transactions: List<Transaction>
+------------------
+| + deposit(amount: double, date: LocalDate)
+| + withdraw(amount: double, date: LocalDate)
+| + deposit(amount: double)
+| + withdraw(amount: double)
+| + getTransactions(): List<Transaction>
+| + getStatement(): List<String>
+-----------------           
+---------------------
+
+------------------    
+| CurrentAccount |    
+------------------    
+| (no extra)     |    
+------------------ 
+
+---------------------   
+
+------------------
+| SavingsAccount |
+-----------------+
+| (no extra)     |
+------------------
+
+---------------------  
+
+------------------
+|  Transaction   |
+------------------
+| - date: LocalDate
+| - amount: double
+| - balance: double
+------------------
+| + toString(): String
+------------------

src/main/java/com/booleanuk/core/Account.java

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+package com.booleanuk.core;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Collections;
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+
+public abstract class Account {
+    protected List<Transaction> transactions;
+    protected double balance;
+
+    private static final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd/MM/yyyy");
+
+    public Account(){
+        this.transactions = new ArrayList<>();
+        this.balance = 0;
+    }
+
+    public List<Transaction> getTransactions(){
+        return transactions;
+    }
+
+    public void deposit(double amount, LocalDate date) {
+        balance += amount;
+        transactions.add(new Transaction(date, amount, balance));
+    }
+
+    public void withdraw(double amount, LocalDate date) {
+        balance -= amount;
+        transactions.add(new Transaction(date, -amount, balance));
+    }
+
+    public void deposit(double amount) {
+        deposit(amount, LocalDate.now());
+    }
+
+    public void withdraw(double amount) {
+        withdraw(amount, LocalDate.now());
+    }
+
+    public List<String> getStatement() {
+        List<Transaction> reversed = new ArrayList<>(transactions);
+        Collections.reverse(reversed);
+
+        List<String> statementLines = new ArrayList<>();
+        for (Transaction t : reversed) {
+            statementLines.add(t.toString());
+        }
+        return statementLines;
+    }
+
+}

src/main/java/com/booleanuk/core/CurrentAccount.java

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+package com.booleanuk.core;
+
+import java.util.List;
+import java.util.ArrayList;
+
+public class CurrentAccount extends Account {
+    public CurrentAccount() {
+        super();
+    }
+}

src/main/java/com/booleanuk/core/SavingsAccount.java

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+package com.booleanuk.core;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class SavingsAccount extends Account{
+    public SavingsAccount(){
+        super();
+    }
+
+}

src/main/java/com/booleanuk/core/Transaction.java

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+package com.booleanuk.core;
+
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.util.Locale;
+
+public class Transaction {
+    private LocalDate date;
+    private double amount;
+    private double balanceAfter;
+
+    private static final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd/MM/yyyy");
+
+    public Transaction(LocalDate date, double amount, double balanceAfter) {
+        this.date = date;
+        this.amount = amount;
+        this.balanceAfter = balanceAfter;
+    }
+
+    public LocalDate getDate() {
+        return date;
+    }
+
+    public double getAmount() {
+        return amount;
+    }
+
+    public double getBalanceAfter() {
+        return balanceAfter;
+    }
+
+    @Override
+    public String toString() {
+        if (amount > 0) {
+            return date.format(formatter) + " || " +
+                    String.format(Locale.US, "%.2f", amount) + " || " +
+                    String.format(Locale.US, "%.2f", balanceAfter);
+        } else {
+            return date.format(formatter) + " || " +
+                    String.format(Locale.US, "%.2f", Math.abs(amount)) + " || " +
+                    String.format(Locale.US, "%.2f", balanceAfter);
+        }
+    }
+}

src/test/java/com/booleanuk/core/BankTest.java

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+package com.booleanuk.core;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import java.time.LocalDate;
+import java.util.List;
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.BeforeEach;
+
+public class BankTest {
+    CurrentAccount currentAccount;
+    SavingsAccount savingsAccount;
+
+    @BeforeEach
+    void setUp() {
+        currentAccount = new CurrentAccount();
+        savingsAccount = new SavingsAccount();
+    }
+
+    @Test
+    public void createCurrentAccount(){
+        assertNotNull(currentAccount, "Current account created");
+    }
+
+    @Test
+    public void newCurrentAccount_ShouldHaveNoTransactions(){
+        List<Transaction> transactions = currentAccount.getTransactions();
+        assertTrue(transactions.isEmpty(), "new current account with no Transactions");
+    }
+
+    @Test
+    public void createSavingsAccount(){
+        assertNotNull(savingsAccount, "Savings account created");
+    }
+
+    @Test
+    public void newSavingsAccount_ShouldHaveNoTransactions(){
+        List<Transaction> transactions = savingsAccount.getTransactions();
+        assertTrue(transactions.isEmpty(), "new savings account with no Transactions");
+    }
+
+    @Test
+    public void savingsAccount_statement_ShouldDisplayAllTransactionsWithBalance(){
+        savingsAccount.deposit(1000, LocalDate.of(2025, 8, 13));
+        savingsAccount.deposit(2000, LocalDate.of(2025, 9, 23));
+        savingsAccount.withdraw(1500, LocalDate.of(2025, 9, 25));
+
+        List<String> statement = savingsAccount.getStatement();
+
+        assertEquals("25/09/2025 || 1500.00 || 1500.00", statement.get(0));
+        assertEquals("23/09/2025 || 2000.00 || 3000.00", statement.get(1));
+        assertEquals("13/08/2025 || 1000.00 || 1000.00", statement.get(2));
+
+    }
+
+    @Test
+    public void currentAccount_statement_ShouldDisplayAllTransactionsWithBalance(){
+        currentAccount.deposit(10000, LocalDate.of(2025, 8, 12));
+        currentAccount.withdraw(1000, LocalDate.of(2025, 8, 13));
+        currentAccount.withdraw(2000, LocalDate.of(2025, 9, 23));
+        currentAccount.deposit(1500, LocalDate.of(2025, 9, 25));
+
+        List<String> statement2 = currentAccount.getStatement();
+
+        assertEquals("25/09/2025 || 1500.00 || 8500.00", statement2.get(0));
+        assertEquals("23/09/2025 || 2000.00 || 7000.00", statement2.get(1));
+        assertEquals("13/08/2025 || 1000.00 || 9000.00", statement2.get(2));
+        assertEquals("12/08/2025 || 10000.00 || 10000.00", statement2.get(3));
+    }
+}