minimal changes to allow for custom error decoding

newsfragments/2795.feature.rst

@@ -0,0 +1 @@
+Add support for custom revert errors

web3/_utils/contract_sources/RevertContract.sol

@@ -1,15 +1,26 @@
-pragma solidity >=0.6.1;
+pragma solidity ^0.8.4;
+
+error Unauthorized();
+error UnauthorizedWithMessage(string errorMessage);
 
 contract RevertContract {
-  function normalFunction() public pure returns (bool) {
-      return true;
-  }
+    function customErrorWithoutMessage() public pure {
+        revert Unauthorized();
+    }
+
+    function customErrorWithMessage() public pure {
+        revert UnauthorizedWithMessage("You are not authorized");
+    }
+
+    function normalFunction() public pure returns (bool) {
+        return true;
+    }
 
-  function revertWithMessage() public pure {
-      revert('Function has been reverted.');
-  }
+    function revertWithMessage() public pure {
+        revert('Function has been reverted.');
+    }
 
-  function revertWithoutMessage() public pure {
-      revert();
-  }
+    function revertWithoutMessage() public pure {
+        revert();
+    }
 }

web3/_utils/contract_sources/contract_data/revert_contract.py

@@ -1,12 +1,34 @@
 """
 Generated by `compile_contracts.py` script.
-Compiled with Solidity v0.8.19.
+Compiled with Solidity v0.8.17.
 """
 
 # source: web3/_utils/contract_sources/RevertContract.sol:RevertContract
-REVERT_CONTRACT_BYTECODE = "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"  # noqa: E501
-REVERT_CONTRACT_RUNTIME = "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"  # noqa: E501
+REVERT_CONTRACT_BYTECODE = "0x608060405234801561001057600080fd5b506102ad806100206000396000f3fe608060405234801561001057600080fd5b50600436106100575760003560e01c8063185c38a41461005c578063bc53eca814610066578063c06a97cb14610070578063d67e4b841461007a578063e766d49814610098575b600080fd5b6100646100a2565b005b61006e6100dd565b005b610078610118565b005b61008261011d565b60405161008f9190610173565b60405180910390f35b6100a0610126565b005b6040517f08c379a00000000000000000000000000000000000000000000000000000000081526004016100d4906101eb565b60405180910390fd5b6040517f9553947a00000000000000000000000000000000000000000000000000000000815260040161010f90610257565b60405180910390fd5b600080fd5b60006001905090565b6040517f82b4290000000000000000000000000000000000000000000000000000000000815260040160405180910390fd5b60008115159050919050565b61016d81610158565b82525050565b60006020820190506101886000830184610164565b92915050565b600082825260208201905092915050565b7f46756e6374696f6e20686173206265656e2072657665727465642e0000000000600082015250565b60006101d5601b8361018e565b91506101e08261019f565b602082019050919050565b60006020820190508181036000830152610204816101c8565b9050919050565b7f596f7520617265206e6f7420617574686f72697a656400000000000000000000600082015250565b600061024160168361018e565b915061024c8261020b565b602082019050919050565b6000602082019050818103600083015261027081610234565b905091905056fea2646970667358221220c90b36e5aeee601ff5cbcb4c09ca883f8fb491dcd68715bfe22db08d2cd76bd064736f6c63430008110033"  # noqa: E501
+REVERT_CONTRACT_RUNTIME = "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"  # noqa: E501
 REVERT_CONTRACT_ABI = [
+    {"inputs": [], "name": "Unauthorized", "type": "error"},
+    {
+        "inputs": [
+            {"internalType": "string", "name": "errorMessage", "type": "string"}
+        ],
+        "name": "UnauthorizedWithMessage",
+        "type": "error",
+    },
+    {
+        "inputs": [],
+        "name": "customErrorWithMessage",
+        "outputs": [],
+        "stateMutability": "pure",
+        "type": "function",
+    },
+    {
+        "inputs": [],
+        "name": "customErrorWithoutMessage",
+        "outputs": [],
+        "stateMutability": "pure",
+        "type": "function",
+    },
     {
         "inputs": [],
         "name": "normalFunction",

web3/_utils/method_formatters.py

@@ -94,6 +94,7 @@
 )
 from web3.exceptions import (
     BlockNotFound,
+    ContractCustomError,
     ContractLogicError,
     OffchainLookup,
     TransactionNotFound,
@@ -757,6 +758,13 @@ def raise_contract_logic_error_on_revert(response: RPCResponse) -> RPCResponse:
         )
         raise OffchainLookup(offchain_lookup_payload)
 
+    # Solidity 0.8.4 introduced custom error messages that allow args to
+    # be passed in (or not). See:
+    # https://blog.soliditylang.org/2021/04/21/custom-errors/
+    if len(data) >= 10 and not data[:10] == "0x08c379a0":
+        # raising along with the data value to allow processing in user code
+        raise ContractCustomError(data)
+
     # Geth case:
     if "message" in response["error"] and response["error"].get("code", "") == 3:
         raise ContractLogicError(response["error"]["message"])

web3/_utils/module_testing/eth_module.py

@@ -55,6 +55,7 @@
 )
 from web3.exceptions import (
     BlockNotFound,
+    ContractCustomError,
     ContractLogicError,
     InvalidAddress,
     InvalidTransaction,
@@ -977,6 +978,44 @@ async def test_eth_call_revert_without_msg(
             )
             await async_w3.eth.call(txn_params)
 
+    @pytest.mark.asyncio
+    async def test_eth_call_revert_custom_error_with_msg(
+        self,
+        async_w3: "AsyncWeb3",
+        revert_contract: "Contract",
+        unlocked_account: ChecksumAddress,
+    ) -> None:
+        data = revert_contract.encodeABI(
+            fn_name="UnauthorizedWithMessage", args=["You are not authorized"]
+        )
+        txn_params = revert_contract._prepare_transaction(
+            fn_name="customErrorWithMessage",
+            transaction={
+                "from": unlocked_account,
+                "to": revert_contract.address,
+            },
+        )
+        with pytest.raises(ContractCustomError, match=data):
+            await async_w3.eth.call(txn_params)
+
+    @pytest.mark.asyncio
+    async def test_eth_call_revert_custom_error_without_msg(
+        self,
+        async_w3: "AsyncWeb3",
+        revert_contract: "Contract",
+        unlocked_account: ChecksumAddress,
+    ) -> None:
+        data = revert_contract.encodeABI(fn_name="Unauthorized")
+        txn_params = revert_contract._prepare_transaction(
+            fn_name="customErrorWithoutMessage",
+            transaction={
+                "from": unlocked_account,
+                "to": revert_contract.address,
+            },
+        )
+        with pytest.raises(ContractCustomError, match=data):
+            await async_w3.eth.call(txn_params)
+
     @pytest.mark.asyncio
     async def test_eth_call_offchain_lookup(
         self,
@@ -3225,6 +3264,42 @@ def test_eth_call_revert_without_msg(
             )
             w3.eth.call(txn_params)
 
+    def test_eth_call_custom_error_revert_with_msg(
+        self,
+        w3: "Web3",
+        revert_contract: "Contract",
+        unlocked_account: ChecksumAddress,
+    ) -> None:
+        data = revert_contract.encodeABI(
+            fn_name="UnauthorizedWithMessage", args=["You are not authorized"]
+        )
+        txn_params = revert_contract._prepare_transaction(
+            fn_name="customErrorWithMessage",
+            transaction={
+                "from": unlocked_account,
+                "to": revert_contract.address,
+            },
+        )
+        with pytest.raises(ContractCustomError, match=data):
+            w3.eth.call(txn_params)
+
+    def test_eth_call_custom_error_revert_without_msg(
+        self,
+        w3: "Web3",
+        revert_contract: "Contract",
+        unlocked_account: ChecksumAddress,
+    ) -> None:
+        data = revert_contract.encodeABI(fn_name="Unauthorized")
+        txn_params = revert_contract._prepare_transaction(
+            fn_name="customErrorWithoutMessage",
+            transaction={
+                "from": unlocked_account,
+                "to": revert_contract.address,
+            },
+        )
+        with pytest.raises(ContractCustomError, match=data):
+            w3.eth.call(txn_params)
+
     def test_eth_call_offchain_lookup(
         self,
         w3: "Web3",
@@ -3458,6 +3533,42 @@ def test_eth_estimate_gas_revert_without_msg(
             )
             w3.eth.estimate_gas(txn_params)
 
+    def test_eth_estimate_gas_custom_error_revert_with_msg(
+        self,
+        w3: "Web3",
+        revert_contract: "Contract",
+        unlocked_account: ChecksumAddress,
+    ) -> None:
+        data = revert_contract.encodeABI(
+            fn_name="UnauthorizedWithMessage", args=["You are not authorized"]
+        )
+        txn_params = revert_contract._prepare_transaction(
+            fn_name="customErrorWithMessage",
+            transaction={
+                "from": unlocked_account,
+                "to": revert_contract.address,
+            },
+        )
+        with pytest.raises(ContractCustomError, match=data):
+            w3.eth.estimate_gas(txn_params)
+
+    def test_eth_estimate_gas_custom_error_revert_without_msg(
+        self,
+        w3: "Web3",
+        revert_contract: "Contract",
+        unlocked_account: ChecksumAddress,
+    ) -> None:
+        data = revert_contract.encodeABI(fn_name="Unauthorized")
+        txn_params = revert_contract._prepare_transaction(
+            fn_name="customErrorWithoutMessage",
+            transaction={
+                "from": unlocked_account,
+                "to": revert_contract.address,
+            },
+        )
+        with pytest.raises(ContractCustomError, match=data):
+            w3.eth.estimate_gas(txn_params)
+
     def test_eth_estimate_gas(
         self, w3: "Web3", unlocked_account_dual_type: ChecksumAddress
     ) -> None:

web3/exceptions.py

@@ -251,6 +251,12 @@ class ContractLogicError(Web3Exception):
     """
 
 
+class ContractCustomError(ContractLogicError):
+    """
+    Raised on a contract revert custom error
+    """
+
+
 class OffchainLookup(ContractLogicError):
     """
     Raised when a contract reverts with OffchainLookup as described in EIP-3668