fix: estimate gas

ape_safe/accounts.py

@@ -459,8 +459,21 @@ def load_submitter(
 
     def prepare_transaction(self, txn: TransactionAPI) -> TransactionAPI:
         # NOTE: Need to override `AccountAPI` behavior for balance checks
+        if txn.gas_limit is None:
+            txn.gas_limit = self.estimate_gas_cost(txn=txn)
+
         return self.provider.prepare_transaction(txn)
 
+    def estimate_gas_cost(self, **kwargs) -> int:
+        operation = kwargs.pop("operation", 0)
+        txn = kwargs.pop("txn", self.as_transaction(**kwargs))
+        return (
+            self.client.estimate_gas_cost(
+                txn.receiver or ZERO_ADDRESS, txn.value, txn.data, operation=operation
+            )
+            or 0
+        )
+
     def _preapproved_signature(
         self, signer: Union[AddressType, BaseAddress, str]
     ) -> MessageSignature:

ape_safe/client/__init__.py

@@ -162,6 +162,20 @@ def post_signatures(
 
             raise  # The error from BaseClient we are already raising (no changes)
 
+    def estimate_gas_cost(
+        self, receiver: AddressType, value: int, data: bytes, operation: int = 0
+    ) -> Optional[int]:
+        url = f"safes/{self.address}/multisig-transactions/estimations"
+        request: Dict = {
+            "to": receiver,
+            "value": value,
+            "data": HexBytes(data).hex(),
+            "operation": operation,
+        }
+        result = self._post(url, json=request).json()
+        gas = result.get("safeTxGas")
+        return int(HexBytes(gas).hex(), 16)
+
 
 __all__ = [
     "ExecutedTxData",

ape_safe/client/base.py

@@ -57,6 +57,11 @@ def post_signatures(
         signatures: Dict[AddressType, MessageSignature],
     ): ...
 
+    @abstractmethod
+    def estimate_gas_cost(
+        self, receiver: AddressType, value: int, data: bytes, operation: int = 0
+    ) -> Optional[int]: ...
+
     """Shared methods"""
 
     def get_transactions(

ape_safe/client/mock.py

@@ -1,5 +1,5 @@
 from datetime import datetime, timezone
-from typing import Dict, Iterator, List, Union, cast
+from typing import Dict, Iterator, List, Optional, Union, cast
 
 from ape.contracts import ContractInstance
 from ape.types import AddressType, MessageSignature
@@ -109,3 +109,8 @@ def post_signatures(
                     signatureType=SignatureType.EOA,
                 )
             )
+
+    def estimate_gas_cost(
+        self, receiver: AddressType, value: int, data: bytes, operation: int = 0
+    ) -> Optional[int]:
+        return None  # Estimate gas normally

tests/functional/test_account.py

@@ -19,7 +19,7 @@ def test_init(safe, OWNERS, THRESHOLD, safe_contract):
     assert safe.next_nonce == 0
 
 
-@pytest.mark.parametrize("mode", ["impersonate", "api", "sign"])
+@pytest.mark.parametrize("mode", ("impersonate", "api", "sign"))
 def test_swap_owner(safe, accounts, OWNERS, mode):
     impersonate = mode == "impersonate"
     submit = mode != "api"
@@ -30,21 +30,24 @@ def test_swap_owner(safe, accounts, OWNERS, mode):
     # NOTE: Since the signers are processed in order, we replace the last account
 
     prev_owner = safe.compute_prev_signer(old_owner)
-    exec_transaction = lambda: safe.contract.swapOwner(  # noqa: E731
-        prev_owner,
-        old_owner,
-        new_owner,
-        sender=safe,
-        impersonate=impersonate,
-        submit=submit,
-    )
+
+    def exec_transaction():
+        return safe.contract.swapOwner(
+            prev_owner,
+            old_owner,
+            new_owner,
+            sender=safe,
+            impersonate=impersonate,
+            submit=submit,
+        )
 
     if submit:
         receipt = exec_transaction()
 
     else:
         # Attempting to execute should raise `SignatureError` and push `safe_tx` to mock client
-        assert len(list(safe.client.get_transactions(confirmed=False))) == 0
+        size = len(list(safe.client.get_transactions(confirmed=False)))
+        assert size == 0
 
         with pytest.raises(SignatureError):
             exec_transaction()
@@ -78,21 +81,22 @@ def test_swap_owner(safe, accounts, OWNERS, mode):
     assert new_owner.address in safe.signers
 
 
-@pytest.mark.parametrize("mode", ["impersonate", "api", "sign"])
+@pytest.mark.parametrize("mode", ("impersonate", "api", "sign"))
 def test_add_owner(safe, accounts, OWNERS, mode):
     impersonate = mode == "impersonate"
     submit = mode != "api"
 
     new_owner = accounts[len(OWNERS)]  # replace owner 1 with account N + 1
     assert new_owner.address not in safe.signers
 
-    exec_transaction = lambda: safe.contract.addOwnerWithThreshold(  # noqa: E731
-        new_owner,
-        safe.confirmations_required,
-        sender=safe,
-        impersonate=impersonate,
-        submit=submit,
-    )
+    def exec_transaction():
+        return safe.contract.addOwnerWithThreshold(
+            new_owner,
+            safe.confirmations_required,
+            sender=safe,
+            impersonate=impersonate,
+            submit=submit,
+        )
 
     if submit:
         receipt = exec_transaction()