Create test_blockchain.py

tests/test_blockchain.py

@@ -0,0 +1,41 @@
+import unittest
+from blockchain import Blockchain
+
+class TestBlockchain(unittest.TestCase):
+    def setUp(self):
+        self.blockchain = Blockchain()
+
+    def test_create_genesis_block(self):
+        self.assertEqual(self.blockchain.chain[0].index, 0)
+        self.assertEqual(self.blockchain.chain[0].previous_hash, "0" * 64)
+        self.assertEqual(self.blockchain.chain[0].data, "Genesis Block")
+        self.assertEqual(self.blockchain.chain[0].timestamp, 1234567890)
+        self.assertEqual(self.blockchain.chain[0].hash, "hash_value")  # Replace with actual hash value
+
+    def test_add_block(self):
+        self.blockchain.add_block("data")
+        self.assertEqual(len(self.blockchain.chain), 2)
+        self.assertEqual(self.blockchain.chain[1].index, 1)
+        self.assertEqual(self.blockchain.chain[1].previous_hash, self.blockchain.chain[0].hash)
+        self.assertEqual(self.blockchain.chain[1].data, "data")
+        self.assertEqual(self.blockchain.chain[1].timestamp, 1234567891)
+        self.assertEqual(self.blockchain.chain[1].hash, "hash_value")  # Replace with actual hash value
+
+    def test_is_valid(self):
+        self.assertTrue(self.blockchain.is_valid())
+
+        # Test invalid blockchain with modified data
+        self.blockchain.chain[1].data = "modified_data"
+        self.assertFalse(self.blockchain.is_valid())
+
+        # Test invalid blockchain with modified previous hash
+        self.blockchain.chain[1].previous_hash = "modified_previous_hash"
+        self.assertFalse(self.blockchain.is_valid())
+
+        # Test invalid blockchain with modified index
+        self.blockchain.chain[1].index = 2
+        self.assertFalse(self.blockchain.is_valid())
+
+        # Test invalid blockchain with modified genesis block
+        self.blockchain.chain[0].data = "modified_genesis_block"
+        self.assertFalse(self.blockchain.is_valid())