Issue1560

newsfragments/1560.bugfix.rst

@@ -0,0 +1,9 @@
+Fixed hasattr overloader method in the web3.ContractEvent class by implementing a try/except handler
+that returns False if an exception is raised in the __getattr__ overloader method 
+(since __getattr__ HAS to be called in every __hasattr__ call). 
+
+Created an Exception class called 'ABIEventFunctionNotFound', which inherits from both AttributeError and 
+MismatchedABI, and replaced the MismatchedABI raise with a raise to the created class in the __getattr__ 
+overloader method of the web3.ContractEvent object. 
+
+Created the test scripts 'test_contract_events_hasattr.py' and 'test_contract_events_getattr.py'

newsfragments/1588.misc.rst

@@ -0,0 +1 @@
+Added block_identifier parameter to `Contract.estimateGas`

tests/core/contracts/test_contract_constructor_estimateGas.py

@@ -0,0 +1,15 @@
+import pytest
+
+abi = """[{"anonymous":false,"inputs":[{"indexed":false,"name":"_bar","type":"string"}],"name":"barred","type":"event"},{"constant":false,"inputs":[{"name":"_bar","type":"string"}],"name":"setBar","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"inputs":[],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"constant":true,"inputs":[],"name":"bar","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"}]"""  # noqa: E501
+# This bytecode is the output of compiling with
+# solc version:0.5.3+commit.10d17f24.Emscripten.clang
+bytecode = """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""" 
+block_identifier = 'latest'
+
+def test_contract_estimateGas(web3, transaction=None):
+    contract = web3.eth.contract(abi=abi, bytecode=bytecode)
+    gas_estimate = contract.constructor().estimateGas(transaction=transaction, block_identifier=block_identifier)
+    deploy_txn = contract.constructor().transact({'from': Web3.toChecksumAddress(Web3.eth.accounts[0])})
+    txn_receipt = web3.eth.waitForTransactionReceipt(deploy_txn)
+    gas_used = txn_receipt.get('gasUsed')
+    assert abs(gas_estimate - gas_used) < 21000

tests/core/contracts/test_contract_events_getattr.py

@@ -0,0 +1,18 @@
+import pytest 
+import json 
+
+CONTRACT_ABI = json.loads('[{"constant":false,"inputs":[],"name":"return13","outputs":[{"name":"result","type":"int256"}],"type":"function"},{"constant":true,"inputs":[],"name":"counter","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":false,"inputs":[{"name":"amt","type":"uint256"}],"name":"increment","outputs":[{"name":"result","type":"uint256"}],"type":"function"},{"constant":false,"inputs":[{"name":"a","type":"int256"},{"name":"b","type":"int256"}],"name":"add","outputs":[{"name":"result","type":"int256"}],"type":"function"},{"constant":false,"inputs":[],"name":"increment","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":false,"inputs":[{"name":"a","type":"int256"}],"name":"multiply7","outputs":[{"name":"result","type":"int256"}],"type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"value","type":"uint256"}],"name":"Increased","type":"event"}]')  # noqa: E501
+
+def test_contract_event_getattr(Web3, EthereumTesterProvider, event_name, expected_existence):
+    web3 = Web3(EthereumTesterProvider)
+    contract = web3.eth.contract(abi=CONTRACT_ABI)
+    try:
+        getattr(contract.events, event_name) 
+        result = True 
+    except Exception as e:
+        result = False
+    if result == expected_existence:
+        return True 
+    else:
+        return False
+

tests/core/contracts/test_contract_events_hasattr.py

@@ -0,0 +1,11 @@
+import pytest 
+import json 
+
+CONTRACT_ABI = json.loads('[{"constant":false,"inputs":[],"name":"return13","outputs":[{"name":"result","type":"int256"}],"type":"function"},{"constant":true,"inputs":[],"name":"counter","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":false,"inputs":[{"name":"amt","type":"uint256"}],"name":"increment","outputs":[{"name":"result","type":"uint256"}],"type":"function"},{"constant":false,"inputs":[{"name":"a","type":"int256"},{"name":"b","type":"int256"}],"name":"add","outputs":[{"name":"result","type":"int256"}],"type":"function"},{"constant":false,"inputs":[],"name":"increment","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":false,"inputs":[{"name":"a","type":"int256"}],"name":"multiply7","outputs":[{"name":"result","type":"int256"}],"type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"value","type":"uint256"}],"name":"Increased","type":"event"}]')  # noqa: E501
+
+def test_contract_event_hasattr(Web3, EthereumTesterProvider, event_name, expected):
+    web3 = Web3(EthereumTesterProvider)
+    contract = web3.eth.contract(abi=CONTRACT_ABI)
+    if hasattr(contract.events, event_name) == expected:
+        return True 
+    return False 

web3/contract.py

@@ -116,6 +116,7 @@
     InvalidEventABI,
     LogTopicError,
     MismatchedABI,
+    ABIEventFunctionNotFound,
     NoABIEventsFound,
     NoABIFound,
     NoABIFunctionsFound,
@@ -239,7 +240,7 @@ def __getattr__(self, event_name: str) -> "ContractEvent":
                 "Are you sure you provided the correct contract abi?"
             )
         elif event_name not in self.__dict__['_events']:
-            raise MismatchedABI(
+            raise ABIEventFunctionNotFound(
                 "The event '{}' was not found in this contract's abi. ".format(event_name),
                 "Are you sure you provided the correct contract abi?"
             )
@@ -257,6 +258,12 @@ def __iter__(self) -> Iterable["ContractEvent"]:
         for event in self._events:
             yield self[event['name']]
 
+    def __hasattr__(self, event_name: str) -> bool:
+        try:
+            return event_name in self.__dict__['_events']
+        except ABIEventFunctionNotFound:
+            return False
+
 
 class Contract:
     """Base class for Contract proxy classes.

web3/exceptions.py

@@ -69,6 +69,12 @@ class MismatchedABI(Exception):
     """
     pass
 
+class ABIEventFunctionNotFound(AttributeError, MismatchedABI):
+    """
+    Raised when an attempt is made to access a function/event 
+    that does not exist in the ABI.
+    """
+    pass 
 
 class FallbackNotFound(Exception):
     """