add tests for StockFileHandler and refactor getNetworthTest in player

src/test/java/edu/ntnu/idi/idatt2003/gruppe42/Model/PlayerTest.java

@@ -64,6 +64,7 @@ void getTransactionArchiveTest() {
   void getMoneyTest() {
     assertEquals(new BigDecimal("10000"), player.getMoney());
   }
+
   @Test
   void withdrawExactAmountTest() {
     player.withdrawMoney(new BigDecimal("10000"));
@@ -72,11 +73,10 @@ void withdrawExactAmountTest() {
 
   @Test
   void getNetworthTest() {
-
     // Starting with 10000 money and adding 5000 moneys worth of AAPL then calculating the networth
     // with commissions taken account of will result in this:
     // 10000 + 5000 - (5000 * 0.01) = 14950
     player.getPortfolio().addShare(new Share(new Stock("AAPL", "Apple Inc.", new BigDecimal("5000")), new BigDecimal("1"), new BigDecimal("5000")));
-    assertEquals(new BigDecimal("14950"), player.getNetWorth());
+    assertEquals(new BigDecimal("14950.00"), player.getNetWorth());
   }
 }

src/test/java/edu/ntnu/idi/idatt2003/gruppe42/Model/StockFileHandlerTest.java

@@ -0,0 +1,40 @@
+package edu.ntnu.idi.idatt2003.gruppe42.Model;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.IOException;
+import java.math.BigDecimal;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+public class StockFileHandlerTest {
+
+  @Test
+  void readFromFileTest() throws IOException {
+    Path testFile = Files.createTempFile("stocks", "csv");
+    Files.writeString(testFile, "AAPL,Apple Inc.,276.43\nMSFT,Microsoft,404.68");
+    List<Stock> stocks = StockFileHandler.readFromFile(testFile);
+    assertEquals(2, stocks.size());
+    assertEquals("AAPL", stocks.get(0).getSymbol());
+  }
+
+  @Test
+  void readFromFileWithCommentsAndEmptyLines() throws IOException {
+    Path testFile = Files.createTempFile("stocks", "csv");
+    Files.writeString(testFile, "#Comment\n\nAAPL,Apple Inc.,276.43");
+    List<Stock> stocks = StockFileHandler.readFromFile(testFile);
+    assertEquals(1, stocks.size());
+  }
+
+  @Test
+  void writeToFileTest() throws IOException {
+    Path testFile = Files.createTempFile("stocks", "csv");
+    List<Stock> stocks = List.of(new Stock("AAPL", "Apple Inc.", new BigDecimal("276.43")));
+    StockFileHandler.writeToFile(testFile, stocks);
+    List<String> lines = Files.readAllLines(testFile);
+    assertTrue(lines.get(2).startsWith("AAPL,Apple Inc.,276.43"));
+  }
+}