feat: decode multisend payload and add calls from it (#59)

* feat: decode and add calls to multisend from calldata

* test: decoded multisend encodes as calldata

* lint: happy bot

* docs: rename multicall to multisend, fix wrong example, decode docs

ape_safe/multisend.py

@@ -1,6 +1,9 @@
+from io import BytesIO
+
+from ape import convert
 from ape.api import ReceiptAPI, TransactionAPI
 from ape.contracts.base import ContractInstance, ContractTransactionHandler
-from ape.types import ContractType, HexBytes
+from ape.types import AddressType, ContractType, HexBytes
 from ape.utils import ManagerAccessMixin, cached_property
 from eth_abi.packed import encode_packed
 
@@ -112,24 +115,24 @@ class MultiSend(ManagerAccessMixin):
 
     def __init__(self) -> None:
         """
-        Initialize a new Multicall session object. By default, there are no calls to make.
+        Initialize a new MultiSend session object. By default, there are no calls to make.
         """
         self.calls: list[dict] = []
 
     @classmethod
     def inject(cls):
         """
-        Create the multicall module contract on-chain, so we can use it.
+        Create the multisend module contract on-chain, so we can use it.
         Must use a provider that supports ``debug_setCode``.
 
         Usage example::
 
-            from ape_ethereum import multicall
+            from ape_safe.multisend import MultiSend
 
             @pytest.fixture(scope="session")
-            def use_multicall():
-                # NOTE: use this fixture any test where you want to use a multicall
-                multicall.BaseMulticall.deploy()
+            def multisend():
+                MultiSend.inject()
+                return MultiSend()
         """
         active_provider = cls.network_manager.active_provider
         assert active_provider, "Must be connected to an active network to deploy"
@@ -166,7 +169,7 @@ def add(
         value=0,
     ) -> "MultiSend":
         """
-        Adds a call to the Multicall session object.
+        Append a call to the MultiSend session object.
 
         Raises:
             :class:`InvalidOption`: If one of the kwarg modifiers is not able to be used.
@@ -218,11 +221,11 @@ def encoded_calls(self):
 
     def __call__(self, **txn_kwargs) -> ReceiptAPI:
         """
-        Execute the Multicall transaction. The transaction will broadcast again every time
+        Execute the MultiSend transaction. The transaction will broadcast again every time
         the ``Transaction`` object is called.
 
         Raises:
-            :class:`UnsupportedChain`: If there is not an instance of Multicall3 deployed
+            :class:`UnsupportedChain`: If there is not an instance of MultiSend deployed
               on the current chain at the expected address.
 
         Args:
@@ -238,7 +241,7 @@ def __call__(self, **txn_kwargs) -> ReceiptAPI:
 
     def as_transaction(self, **txn_kwargs) -> TransactionAPI:
         """
-        Encode the Multicall transaction as a ``TransactionAPI`` object, but do not execute it.
+        Encode the MultiSend transaction as a ``TransactionAPI`` object, but do not execute it.
 
         Returns:
             :class:`~ape.api.transactions.TransactionAPI`
@@ -253,3 +256,27 @@ def as_transaction(self, **txn_kwargs) -> TransactionAPI:
             data=self.handler.encode_input(b"".join(self.encoded_calls)),
             **txn_kwargs,
         )
+
+    def add_from_calldata(self, calldata: bytes):
+        """
+        Decode all calls from a multisend calldata and add them to this MultiSend.
+
+        Args:
+            calldata: Calldata encoding the MultiSend.multiSend call
+        """
+        _, args = self.contract.decode_input(calldata)
+        buffer = BytesIO(args["transactions"])
+        while buffer.tell() < len(args["transactions"]):
+            operation = int.from_bytes(buffer.read(1), "big")
+            target = convert(buffer.read(20), AddressType)
+            value = int.from_bytes(buffer.read(32), "big")
+            length = int.from_bytes(buffer.read(32), "big")
+            data = HexBytes(buffer.read(length))
+            self.calls.append(
+                {
+                    "operation": operation,
+                    "target": target,
+                    "value": value,
+                    "callData": data,
+                }
+            )

tests/functional/test_multisend.py

@@ -21,3 +21,11 @@ def test_no_operation(safe, token, vault, multisend):
     multisend.add(vault.transfer, safe, amount)
     with pytest.raises(SafeLogicError, match="Safe transaction failed"):
         multisend(sender=safe, operation=0)
+
+
+def test_decode_multisend(multisend):
+    calldata = bytes.fromhex(
+        "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"  # noqa: E501
+    )
+    multisend.add_from_calldata(calldata)
+    assert multisend.handler.encode_input(b"".join(multisend.encoded_calls)) == calldata