diff --git a/src/test/java/edu/ntnu/idi/idatt2003/g40/mappe/TransactionArchiveTest.java b/src/test/java/edu/ntnu/idi/idatt2003/g40/mappe/TransactionArchiveTest.java
index cf935b8..17726ad 100644
--- a/src/test/java/edu/ntnu/idi/idatt2003/g40/mappe/TransactionArchiveTest.java
+++ b/src/test/java/edu/ntnu/idi/idatt2003/g40/mappe/TransactionArchiveTest.java
@@ -1,3 +1,130 @@
-public class TransactionArchiveTest {
-    
-}
+package edu.ntnu.idi.idatt2003.g40.mappe;
+
+import org.junit.jupiter.api.Test;
+
+import java.math.BigDecimal;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class TransactionArchiveTest {
+
+    private final TransactionCalculator calculator = new TransactionCalculator() {
+        @Override
+        public BigDecimal calculateGross() {
+            return BigDecimal.ZERO;
+        }
+
+        @Override
+        public BigDecimal calculateCommission() {
+            return BigDecimal.ZERO;
+        }
+
+        @Override
+        public BigDecimal calculateTax() {
+            return BigDecimal.ZERO;
+        }
+
+        @Override
+        public BigDecimal calculateTotal() {
+            return BigDecimal.ZERO;
+        }
+    };
+
+    @Test
+    void newArchiveIsEmpty() {
+        TransactionArchive archive = new TransactionArchive();
+
+        assertTrue(archive.isEmpty());
+    }
+
+    @Test
+    void addMakesArchiveNonEmpty() {
+        TransactionArchive archive = new TransactionArchive();
+        Transaction transaction = createPurchase("AAPL", "Apple", 1);
+
+        boolean result = archive.add(transaction);
+
+        assertTrue(result);
+        assertFalse(archive.isEmpty());
+    }
+
+    @Test
+    void getTransactionsReturnsOnlyTransactionsFromGivenWeek() {
+        TransactionArchive archive = new TransactionArchive();
+
+        Transaction transaction1 = createPurchase("AAPL", "Apple", 1);
+        Transaction transaction2 = createSale("TSLA", "Tesla", 2);
+        Transaction transaction3 = createPurchase("NVDA", "Nvidia", 1);
+
+        archive.add(transaction1);
+        archive.add(transaction2);
+        archive.add(transaction3);
+
+        List<Transaction> result = archive.getTransactions(1);
+
+        assertEquals(2, result.size());
+        assertTrue(result.contains(transaction1));
+        assertTrue(result.contains(transaction3));
+    }
+
+    @Test
+    void getPurchasesReturnsOnlyPurchasesFromGivenWeek() {
+        TransactionArchive archive = new TransactionArchive();
+
+        Purchase purchase1 = createPurchase("AAPL", "Apple", 1);
+        Purchase purchase2 = createPurchase("NVDA", "Nvidia", 2);
+        Sale sale = createSale("TSLA", "Tesla", 1);
+
+        archive.add(purchase1);
+        archive.add(purchase2);
+        archive.add(sale);
+
+        List<Purchase> result = archive.getPurchases(1);
+
+        assertEquals(1, result.size());
+        assertTrue(result.contains(purchase1));
+    }
+
+    @Test
+    void getSalesReturnsOnlySalesFromGivenWeek() {
+        TransactionArchive archive = new TransactionArchive();
+
+        Sale sale1 = createSale("TSLA", "Tesla", 1);
+        Sale sale2 = createSale("NVDA", "Nvidia", 2);
+        Purchase purchase = createPurchase("AAPL", "Apple", 1);
+
+        archive.add(sale1);
+        archive.add(sale2);
+        archive.add(purchase);
+
+        List<Sale> result = archive.getSales(1);
+
+        assertEquals(1, result.size());
+        assertTrue(result.contains(sale1));
+    }
+
+    @Test
+    void countDistinctWeeksCountsUniqueWeeksOnly() {
+        TransactionArchive archive = new TransactionArchive();
+
+        archive.add(createPurchase("AAPL", "Apple", 1));
+        archive.add(createSale("TSLA", "Tesla", 1));
+        archive.add(createPurchase("NVDA", "Nvidia", 2));
+        archive.add(createSale("META", "Meta", 3));
+
+        assertEquals(3, archive.countDistinctWeeks());
+    }
+
+    private Purchase createPurchase(String symbol, String company, int week) {
+        Stock stock = new Stock(symbol, company, new BigDecimal("100"));
+        Share share = new Share(stock, BigDecimal.ONE, new BigDecimal("100"));
+        return new Purchase(share, week, calculator);
+    }
+
+    private Sale createSale(String symbol, String company, int week) {
+        Stock stock = new Stock(symbol, company, new BigDecimal("100"));
+        Share share = new Share(stock, BigDecimal.ONE, new BigDecimal("100"));
+        return new Sale(share, week, calculator);
+    }
+}
\ No newline at end of file