[FEATURE]: Implement Canonical Serialization for Blocks and Transactions

minichain/block.py

@@ -2,7 +2,7 @@
 import hashlib
 from typing import List, Optional
 from .transaction import Transaction
-from .serialization import canonical_json_hash
+from .serialization import canonical_json_hash, canonical_json_bytes
 
 def _sha256(data: str) -> str:
     return hashlib.sha256(data.encode()).hexdigest()
@@ -117,3 +117,8 @@ def from_dict(cls, payload: dict):
         if "merkle_root" in payload:
             block.merkle_root = payload["merkle_root"]
         return block
+
+    @property
+    def canonical_payload(self) -> bytes:
+        """Returns the full block (header + body) as canonical bytes for networking."""
+        return canonical_json_bytes(self.to_dict())

tests/test_serialization.py

@@ -0,0 +1,52 @@
+from minichain.serialization import canonical_json_hash
+from minichain.transaction import Transaction
+from minichain.block import Block
+
+def test_raw_data_determinism():
+    print("--- Testing Raw Data Determinism ---")
+    # Same data, different key order
+    data_v1 = {"amount": 100, "nonce": 1, "receiver": "Alice", "sender": "Bob"}
+    data_v2 = {"sender": "Bob", "receiver": "Alice", "nonce": 1, "amount": 100}
+
+    hash_1 = canonical_json_hash(data_v1)
+    hash_2 = canonical_json_hash(data_v2)
+
+    print(f"Hash 1: {hash_1}")
+    print(f"Hash 2: {hash_2}")
+    assert hash_1 == hash_2
+    print("Success: Raw hashes match regardless of key order!\n")
+
+def test_transaction_id_stability():
+    print("--- Testing Transaction ID Stability ---")
+    # Create a transaction
+    tx = Transaction(sender="Alice_PK", receiver="Bob_PK", amount=50, nonce=1)
+
+    first_id = tx.tx_id
+    # Re-triggering the ID calculation
+    second_id = tx.tx_id
+
+    print(f"TX ID: {first_id}")
+    assert first_id == second_id
+    print("Success: Transaction ID is stable and deterministic!\n")
+
+def test_block_hash_consistency():
+    print("--- Testing Block Hash Consistency ---")
+    # Create a block with one transaction
+    tx = Transaction(sender="A", receiver="B", amount=10, nonce=5)
+    block = Block(index=1, previous_hash="0"*64, transactions=[tx], difficulty=2)
+
+    initial_hash = block.compute_hash()
+    print(f"Initial Block Hash: {initial_hash}")
+
+    # Manually re-computing to ensure it's identical
+    assert block.compute_hash() == initial_hash
+    print("Success: Block hash is consistent!\n")
+
+if __name__ == "__main__":
+    try:
+        test_raw_data_determinism()
+        test_transaction_id_stability()
+        test_block_hash_consistency()
+        print("ALL CANONICAL TESTS PASSED!")
+    except AssertionError as e:
+        print("TEST FAILED: Serialization is not deterministic!")