test: add unit tests for multithreading scenarios

2026-06-04 21:00:09 +03:30
parent 6d8bee27f1
commit 73395fa188
10 changed files with 281 additions and 3 deletions
@@ -1,4 +1,56 @@
 package banking;

+import dev.banking.model.BankAccount;
+import org.junit.jupiter.api.Test;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 public class TestB {
-}
+
+    @Test
+    void concurrentDepositWithdraw() throws Exception {
+
+        BankAccount account =
+                new BankAccount(1, 1_000_000);
+
+        ExecutorService executor =
+                Executors.newFixedThreadPool(100);
+
+        CountDownLatch latch =
+                new CountDownLatch(100);
+
+        for (int i = 0; i < 50; i++) {
+
+            executor.submit(() -> {
+
+                for (int j = 0; j < 10000; j++) {
+                    account.deposit(1);
+                }
+
+                latch.countDown();
+            });
+
+            executor.submit(() -> {
+
+                for (int j = 0; j < 10000; j++) {
+                    account.withdraw(1);
+                }
+
+                latch.countDown();
+            });
+        }
+
+        latch.await();
+
+        executor.shutdown();
+
+        assertEquals(
+                1_000_000,
+                account.getBalance()
+        );
+    }
+}