Make kakarot upgradable (#969)

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- [ ] Bugfix
- [ ] Feature
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## What is the current behavior?

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or link to a relevant issue. -->

Resolves #<Issue number>

## What is the new behavior?

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scripts/constants.py

@@ -149,6 +149,7 @@ class ArtifactType(Enum):
     {"contract_name": "EVM", "is_account_contract": False},
     {"contract_name": "OpenzeppelinAccount", "is_account_contract": True},
     {"contract_name": "ERC20", "is_account_contract": False},
+    {"contract_name": "replace_class", "is_account_contract": False},
 ]
 DECLARED_CONTRACTS = [
     {"contract_name": "kakarot", "cairo_version": ArtifactType.cairo0},
@@ -158,6 +159,7 @@ class ArtifactType(Enum):
     {"contract_name": "EVM", "cairo_version": ArtifactType.cairo0},
     {"contract_name": "OpenzeppelinAccount", "cairo_version": ArtifactType.cairo0},
     {"contract_name": "Precompiles", "cairo_version": ArtifactType.cairo1},
+    {"contract_name": "replace_class", "cairo_version": ArtifactType.cairo0},
 ]
 
 EVM_PRIVATE_KEY = os.getenv("EVM_PRIVATE_KEY")

scripts/utils/starknet.py

@@ -79,7 +79,7 @@ async def get_starknet_account(
         raise ValueError(
             "address was not given in arg nor in env variable, see README.md#Deploy"
         )
-    address = int(address, 16)
+    address = int(address, 16) if isinstance(address, str) else address
     private_key = private_key or NETWORK["private_key"]
     if private_key is None:
         raise ValueError(
@@ -348,7 +348,7 @@ def _convert_offset_to_hex(obj):
     )
 
 
-async def deploy_starknet_account(class_hash, private_key=None, amount=1):
+async def deploy_starknet_account(class_hash=None, private_key=None, amount=1):
     salt = random.randint(0, 2**251)
     private_key = private_key or NETWORK["private_key"]
     if private_key is None:
@@ -357,6 +357,7 @@ async def deploy_starknet_account(class_hash, private_key=None, amount=1):
         )
     key_pair = KeyPair.from_private_key(int(private_key, 16))
     constructor_calldata = [key_pair.public_key]
+    class_hash = class_hash or get_declarations()["OpenzeppelinAccount"]
     address = compute_address(
         salt=salt,
         class_hash=class_hash,

src/kakarot/events.cairo

@@ -5,3 +5,7 @@
 @event
 func evm_contract_deployed(evm_contract_address: felt, starknet_contract_address: felt) {
 }
+
+@event
+func kakarot_upgraded(new_class_hash: felt) {
+}

src/kakarot/kakarot.cairo

@@ -8,14 +8,16 @@ from starkware.cairo.common.bool import FALSE, TRUE
 from starkware.cairo.common.cairo_builtins import HashBuiltin, BitwiseBuiltin
 from starkware.cairo.common.math_cmp import is_not_zero
 from starkware.cairo.common.uint256 import Uint256
-from starkware.starknet.common.syscalls import get_caller_address
+from starkware.starknet.common.syscalls import get_caller_address, replace_class
 from starkware.cairo.common.registers import get_fp_and_pc
+from openzeppelin.access.ownable.library import Ownable
 
 // Local dependencies
 from backend.starknet import Starknet
 from kakarot.account import Account
-from kakarot.model import model
+from kakarot.events import kakarot_upgraded
 from kakarot.library import Kakarot
+from kakarot.model import model
 from utils.utils import Helpers
 
 // Constructor
@@ -38,6 +40,19 @@ func constructor{syscall_ptr: felt*, pedersen_ptr: HashBuiltin*, range_check_ptr
     );
 }
 
+// @notive Upgrade the contract
+// @dev Use the replace_hash syscall to upgrade the contract
+// @param new_class_hash The new class hash
+@external
+func upgrade{syscall_ptr: felt*, pedersen_ptr: HashBuiltin*, range_check_ptr}(
+    new_class_hash: felt
+) {
+    Ownable.assert_only_owner();
+    replace_class(new_class_hash);
+    kakarot_upgraded.emit(new_class_hash);
+    return ();
+}
+
 // @notice Set the native token used by kakarot
 // @dev Set the native token which will emulate the role of ETH on Ethereum
 // @param native_token_address_ The address of the native token

tests/end_to_end/conftest.py

@@ -336,3 +336,23 @@ def eth_get_code():
     from scripts.utils.kakarot import eth_get_code
 
     return eth_get_code
+
+
+@pytest.fixture
+def call():
+    """
+    Send a Starknet call.
+    """
+    from scripts.utils.starknet import call
+
+    return call
+
+
+@pytest.fixture
+def invoke():
+    """
+    Send a Starknet transaction.
+    """
+    from scripts.utils.starknet import invoke
+
+    return invoke

tests/end_to_end/test_kakarot.py

@@ -32,6 +32,27 @@ def evm(get_contract):
     return get_contract("EVM")
 
 
+@pytest.fixture(scope="session")
+async def other():
+    """
+    Just another Starknet contract.
+    """
+    from scripts.utils.starknet import deploy_starknet_account, get_starknet_account
+
+    account_info = await deploy_starknet_account()
+    return await get_starknet_account(account_info["address"])
+
+
+@pytest.fixture(scope="session")
+async def class_hashes():
+    """
+    All declared class hashes.
+    """
+    from scripts.utils.starknet import get_declarations
+
+    return get_declarations()
+
+
 @pytest_asyncio.fixture(scope="session")
 async def origin(evm: Contract, addresses):
     """
@@ -184,3 +205,31 @@ async def test_eth_call_should_succeed(
             assert result.success == 1
             assert result.return_data == []
             assert result.gas_used == 21_000
+
+    class TestUpgrade:
+
+        async def test_should_raise_when_caller_is_not_owner(
+            self, starknet, kakarot, invoke, other, class_hashes
+        ):
+            prev_class_hash = await starknet.get_class_hash_at(kakarot.address)
+            await invoke("kakarot", "upgrade", class_hashes["EVM"], account=other)
+            new_class_hash = await starknet.get_class_hash_at(kakarot.address)
+            assert prev_class_hash == new_class_hash
+
+        async def test_should_raise_when_class_hash_is_not_declared(
+            self, starknet, kakarot, invoke
+        ):
+            prev_class_hash = await starknet.get_class_hash_at(kakarot.address)
+            await invoke("kakarot", "upgrade", 0xDEAD)
+            new_class_hash = await starknet.get_class_hash_at(kakarot.address)
+            assert prev_class_hash == new_class_hash
+
+        async def test_should_upgrade_class_hash(
+            self, starknet, kakarot, invoke, class_hashes
+        ):
+            prev_class_hash = await starknet.get_class_hash_at(kakarot.address)
+            await invoke("kakarot", "upgrade", class_hashes["replace_class"])
+            new_class_hash = await starknet.get_class_hash_at(kakarot.address)
+            assert prev_class_hash != new_class_hash
+            assert new_class_hash == class_hashes["replace_class"]
+            await invoke("kakarot", "upgrade", prev_class_hash)

tests/fixtures/replace_class.cairo

@@ -0,0 +1,12 @@
+%lang starknet
+
+from starkware.cairo.common.cairo_builtins import HashBuiltin
+from starkware.starknet.common.syscalls import replace_class
+
+@external
+func upgrade{syscall_ptr: felt*, pedersen_ptr: HashBuiltin*, range_check_ptr}(
+    new_class_hash: felt
+) {
+    replace_class(new_class_hash);
+    return ();
+}