File structure fix

The file structure was configured in a way that caused a package bug. This should fix the problem

src/test/java/edu/ntnu/idi/idatt2003/g40/mappe/ExchangeTest.java

@@ -0,0 +1,3 @@
+public class ExchangeTest {
+
+}

src/test/java/MainTest.java → src/test/java/edu/ntnu/idi/idatt2003/g40/mappe/MainTest.java

@@ -1,2 +1,3 @@
 public class MainTest {
+
 }

src/test/java/edu/ntnu/idi/idatt2003/g40/mappe/PlayerTest.java

@@ -0,0 +1,3 @@
+public class PlayerTest {
+
+}

src/test/java/edu/ntnu/idi/idatt2003/g40/mappe/PortfolioTest.java

@@ -0,0 +1,3 @@
+public class PortfolioTest {
+
+}

src/test/java/edu/ntnu/idi/idatt2003/g40/mappe/PurchaseTest.java

@@ -0,0 +1,3 @@
+public class PurchaseTest {
+
+}

src/test/java/edu/ntnu/idi/idatt2003/g40/mappe/SaleCalculatorTest.java

@@ -0,0 +1,3 @@
+public class SaleCalculatorTest {
+
+}

src/test/java/edu/ntnu/idi/idatt2003/g40/mappe/SaleTest.java

@@ -0,0 +1,3 @@
+public class SaleTest {
+
+}

src/test/java/edu/ntnu/idi/idatt2003/g40/mappe/ShareTest.java

@@ -0,0 +1,3 @@
+public class ShareTest {
+
+}

src/test/java/edu/ntnu/idi/idatt2003/g40/mappe/StockTest.java

@@ -0,0 +1,58 @@
+package edu.ntnu.idi.idatt2003.g40.mappe;
+
+import org.junit.jupiter.api.Test;
+
+import java.math.BigDecimal;
+import java.util.NoSuchElementException;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class StockTest {
+
+    @Test
+    void constructor_setsSymbolAndCompany() {
+        Stock stock = new Stock("AAPL", "Apple Inc.", new BigDecimal("100.00"));
+
+        assertEquals("AAPL", stock.getSymbol());
+        assertEquals("Apple Inc.", stock.getCompany());
+    }
+
+    @Test
+    void getSalesPrice_throwsWhenNoPricesExist_currentImplementation() {
+        Stock stock = new Stock("AAPL", "Apple Inc.", new BigDecimal("100.00"));
+
+        // Because constructor does not add the initial salesPrice to prices,
+        // prices is empty and getLast() throws NoSuchElementException.
+        assertThrows(NoSuchElementException.class, stock::getSalesPrice);
+    }
+
+    @Test
+    void addNewSalesPrice_thenGetSalesPrice_returnsLastAddedPrice() {
+        Stock stock = new Stock("AAPL", "Apple Inc.", new BigDecimal("100.00"));
+
+        stock.addNewSalesPrice(new BigDecimal("123.45"));
+
+        assertEquals(new BigDecimal("123.45"), stock.getSalesPrice());
+    }
+
+    @Test
+    void addNewSalesPrice_twice_getSalesPrice_returnsMostRecent() {
+        Stock stock = new Stock("AAPL", "Apple Inc.", new BigDecimal("100.00"));
+
+        stock.addNewSalesPrice(new BigDecimal("10.00"));
+        stock.addNewSalesPrice(new BigDecimal("20.00"));
+
+        assertEquals(new BigDecimal("20.00"), stock.getSalesPrice());
+    }
+
+    @Test
+    void addNewSalesPrice_allowsNull_currentImplementation() {
+        Stock stock = new Stock("AAPL", "Apple Inc.", new BigDecimal("100.00"));
+
+        stock.addNewSalesPrice(null);
+
+        // List allows nulls; getLast returns null -> should not throw.
+        assertDoesNotThrow(stock::getSalesPrice);
+        assertNull(stock.getSalesPrice());
+    }
+}

src/test/java/edu/ntnu/idi/idatt2003/g40/mappe/TransactionArchiveTest.java

@@ -0,0 +1,3 @@
+public class TransactionArchiveTest {
+
+}

src/test/java/edu/ntnu/idi/idatt2003/g40/mappe/TransactionTest.java

@@ -0,0 +1,3 @@
+public class TransactionTest {
+
+}