Fix bug in contract caller

Author: njgheorghita

newsfragments/1552.bugfix.rst

@@ -0,0 +1 @@
+Minor bugfix in how ContractCaller looks up abi functions.

tests/core/contracts/test_contract_caller_interface.py

@@ -82,9 +82,19 @@ def test_caller_with_empty_abi(web3):
         contract.caller.thisFunctionDoesNotExist()
 
 
+def test_caller_raw_getattr_with_missing_element(math_contract):
+    with pytest.raises(MismatchedABI, match="not found in this contract's ABI"):
+        math_contract.caller.__getattr__('notafunction')
+
+
+def test_caller_raw_getattr_with_present_element(math_contract):
+    attr = math_contract.caller.__getattr__('return13')
+    assert attr
+
+
 def test_caller_with_a_nonexistent_function(math_contract):
     contract = math_contract
-    with pytest.raises(MismatchedABI):
+    with pytest.raises(MismatchedABI, match="not found in this contract's ABI"):
         contract.caller.thisFunctionDoesNotExist()
 
 

web3/contract.py

@@ -1351,8 +1351,7 @@ def __getattr__(self, function_name: str) -> Any:
                 "The ABI for this contract contains no function definitions. ",
                 "Are you sure you provided the correct contract ABI?"
             )
-        # type ignore b/c bug: fix coming in future pr
-        elif function_name not in self._functions:  # type: ignore
+        elif function_name not in set(fn['name'] for fn in self._functions):
             functions_available = ', '.join([fn['name'] for fn in self._functions])
             raise MismatchedABI(
                 "The function '{}' was not found in this contract's ABI. ".format(function_name),