feat(Safe): add exception to show when a feature isn't available

Safe Guard is not available prior to v1.3.0

Author: fubuloubu

ape_safe/accounts.py

@@ -27,6 +27,7 @@
 from .config import SafeConfig
 from .exceptions import (
     ApeSafeError,
+    FeatureNotAvailable,
     NoLocalSigners,
     NotASigner,
     NotEnoughSignatures,
@@ -288,6 +289,9 @@ def modules(self) -> SafeModuleManager:
 
     @property
     def guard(self) -> Optional["ContractInstance"]:
+        if self.version > Version("1.3.0"):
+            raise FeatureNotAvailable("Safe Guard", self.version)
+
         slot = keccak(text="guard_manager.guard.address")
         value = self.provider.get_storage(self.address, slot)
         address = self.network_manager.ecosystem.decode_address(value[-20:])
@@ -300,6 +304,9 @@ def set_guard(
         new_guard: Union[str, AddressType, "BaseAddress"] = ZERO_ADDRESS,
         **tx_args,
     ) -> ReceiptAPI:
+        if self.version > Version("1.3.0"):
+            raise FeatureNotAvailable("Safe Guard", self.version)
+
         if "sender" not in tx_args:
             tx_args["sender"] = self
 

ape_safe/exceptions.py

@@ -8,6 +8,7 @@
     DecodingError,
     SignatureError,
 )
+from packaging.version import Version
 
 if TYPE_CHECKING:
     from ape.types import AddressType
@@ -32,6 +33,11 @@ def __init__(self, safe: "AddressType"):
         )
 
 
+class FeatureNotAvailable(ApeSafeException, NotImplementedError):
+    def __init__(self, feature: str, version: Version):
+        super().__init__(f"Feature '{feature}' does not exist in version {version}")
+
+
 class NotASigner(ApeSafeException):
     def __init__(self, signer: "AddressType"):
         super().__init__(f"{signer} is not a valid signer.")

tests/functional/test_guard.py

@@ -1,4 +1,11 @@
+import pytest
+from packaging.version import Version
+
+
 def test_add_guard(safe, guard, exec_transaction):
+    if safe.version < Version("1.3.0"):
+        pytest.skip(reason="Guard does not exist prior to v1.3.0")
+
     assert safe.guard is None
 
     receipt = exec_transaction(