Add tests for CCIP Read offchain resolution

Author: fselmo

tests/core/contracts/contract_sources/OffchainLookup.sol

@@ -0,0 +1,26 @@
+// This contract is meant to test CCIP Read / Offchain Lookup functionality as part of EIP-3668. Multiple functions
+// may be added here for testing and the contract can be recompiled for `test_offchain_lookup.py` and other tests.
+
+pragma solidity ^0.8.13;
+
+contract OffchainLookup {
+    string[] urls = ["https://web3.py/gateway/{sender}/{data}"];
+
+    error OffchainLookup(address sender, string[] urls, bytes callData, bytes4 callbackFunction, bytes extraData);
+
+    // This function is meant to test that continuous OffchainLookup reverts raise an exception after too many
+    // redirects. This example technically breaks the flow described in EIP-3668 but this is solely meant to trigger
+    // continuous OffchainLookup reverts and test that we catch this sort of activity and stop it. Currently this limit
+    // is set to 4 redirects.
+    function continuousOffchainLookup() external returns(bytes memory) {
+        bytes memory callData;
+
+        revert OffchainLookup(
+            address(this),
+            urls,
+            callData,
+            this.continuousOffchainLookup.selector,
+            callData
+        );
+    }
+}

tests/core/contracts/test_offchain_lookup.py

@@ -0,0 +1,58 @@
+import json
+import pytest
+
+import requests
+
+from web3.exceptions import (
+    TooManyRequests,
+)
+
+
+class MockHttpSuccessResponse:
+    def __init__(self, *args, **_kwargs):
+        pass
+        # assert args[1] == "https://web3.py/gateway/0xf2e246bb76df876cef8b38ae84130f4f55de395b/0x09a3c01b"  # noqa: E501
+
+    @staticmethod
+    def raise_for_status():
+        pass
+
+    @staticmethod
+    def json():
+        return {'data': '0x'}
+
+
+@pytest.fixture
+def OffchainLookup(w3):
+    # compiled from `tests/core/contracts/contract_sources/OffchainLookup.sol`
+    return w3.eth.contract(
+        abi=json.loads('[{"inputs":[{"internalType":"address","name":"sender","type":"address"},{"internalType":"string[]","name":"urls","type":"string[]"},{"internalType":"bytes","name":"callData","type":"bytes"},{"internalType":"bytes4","name":"callbackFunction","type":"bytes4"},{"internalType":"bytes","name":"extraData","type":"bytes"}],"name":"OffchainLookup","type":"error"},{"inputs":[],"name":"continuousOffchainLookup","outputs":[{"internalType":"bytes","name":"","type":"bytes"}],"stateMutability":"view","type":"function"}]'),  # noqa: E501
+        bytecode="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",  # noqa: E501
+        bytecode_runtime="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",  # noqa: E501
+    )
+
+
+@pytest.fixture
+def offchain_lookup_contract(
+    w3, wait_for_block, OffchainLookup, wait_for_transaction, address_conversion_func
+):
+    wait_for_block(w3)
+    deploy_txn_hash = OffchainLookup.constructor().transact({'gas': 10000000})
+    deploy_receipt = wait_for_transaction(w3, deploy_txn_hash)
+    contract_address = address_conversion_func(deploy_receipt['contractAddress'])
+
+    bytecode = w3.eth.get_code(contract_address)
+    assert bytecode == OffchainLookup.bytecode_runtime
+    deployed_offchain_lookup = OffchainLookup(address=contract_address)
+    assert deployed_offchain_lookup.address == contract_address
+    return deployed_offchain_lookup
+
+
+def test_offchain_lookup_raises_on_continuous_redirect(offchain_lookup_contract, monkeypatch):
+    def mock_get(*args, **kwargs):
+        return MockHttpSuccessResponse(*args, **kwargs)
+
+    monkeypatch.setattr(requests.Session, 'get', mock_get)
+
+    with pytest.raises(TooManyRequests, match="Too many CCIP read redirects"):
+        offchain_lookup_contract.caller.continuousOffchainLookup()

web3/_utils/async_transactions.py

@@ -69,7 +69,7 @@ async def async_handle_offchain_lookup(
     formatted_sender = to_hex_if_bytes(offchain_lookup_payload['sender']).lower()
     formatted_data = to_hex_if_bytes(offchain_lookup_payload['callData']).lower()
 
-    if formatted_sender != transaction['to'].lower():
+    if formatted_sender != to_hex_if_bytes(transaction['to']).lower():
         raise ValidationError(
             'Cannot handle OffchainLookup raised inside nested call. Returned `sender` '
             'value does not equal `to` address in transaction.'

web3/_utils/transactions.py

@@ -265,7 +265,7 @@ def handle_offchain_lookup(
     formatted_sender = to_hex_if_bytes(offchain_lookup_payload['sender']).lower()
     formatted_data = to_hex_if_bytes(offchain_lookup_payload['callData']).lower()
 
-    if formatted_sender != transaction['to'].lower():
+    if formatted_sender != to_hex_if_bytes(transaction['to']).lower():
         raise ValidationError(
             'Cannot handle OffchainLookup raised inside nested call. Returned `sender` '
             'value does not equal `to` address in transaction.'

web3/providers/eth_tester/defaults.py

@@ -79,9 +79,9 @@ def call_eth_tester(
         return getattr(eth_tester, fn_name)(*fn_args, **fn_kwargs)
     except TransactionFailed as e:
         possible_data = e.args[0]
-        if isinstance(possible_data, str) and possible_data[:10] == 'b"Uo\\x180\\':
+        if isinstance(possible_data, str) and possible_data[2:10] == 'Uo\\x180\\':
             # EIP-3668 | CCIP Read
-            # b"Uo\\x180\\" is the function selector for:
+            # b"Uo\x180" is the first 4 bytes of the keccak hash for:
             # OffchainLookup(address,string[],bytes,bytes4,bytes)
             parsed_data_as_bytes = ast.literal_eval(possible_data)
             data_payload = parsed_data_as_bytes[4:]  # everything but the function selector