Create test_transaction.py

tests/test_transaction.py

@@ -0,0 +1,39 @@
+import unittest
+from transaction import Transaction
+
+class TestTransaction(unittest.TestCase):
+    def test_create_transaction(self):
+        transaction = Transaction("sender", "receiver", 100)
+        self.assertEqual(transaction.sender, "sender")
+        self.assertEqual(transaction.receiver, "receiver")
+        self.assertEqual(transaction.amount, 100)
+        self.assertEqual(transaction.timestamp, 1234567890)
+        self.assertEqual(transaction.hash, "hash_value")  # Replace with actual hash value
+
+    def test_calculate_hash(self):
+        transaction = Transaction("sender", "receiver", 100)
+        self.assertEqual(transaction.calculate_hash(), "hash_value")  # Replace with actual hash value
+
+    def test_is_valid(self):
+        transaction = Transaction("sender", "receiver", 100)
+        self.assertTrue(transaction.is_valid())
+
+        # Test invalid transaction with modified data
+        transaction.data = "modified_data"
+        self.assertFalse(transaction.is_valid())
+
+        # Test invalid transaction with modified sender
+        transaction.sender = "modified_sender"
+        self.assertFalse(transaction.is_valid())
+
+        # Test invalid transaction with modified receiver
+        transaction.receiver = "modified_receiver"
+        self.assertFalse(transaction.is_valid())
+
+        # Test invalid transaction with modified amount
+        transaction.amount = 200
+        self.assertFalse(transaction.is_valid())
+
+        # Test invalid transaction with modified timestamp
+        transaction.timestamp = 1234567891
+        self.assertFalse(transaction.is_valid())