Merge pull request #853 from eth-brownie/feat-trace-check

Improved handling of trace queries / exceptions

brownie/network/transaction.py

@@ -38,6 +38,11 @@ def trace_property(fn: Callable) -> Any:
     def wrapper(self: "TransactionReceipt") -> Any:
         if self.status < 0:
             return None
+        if not web3.supports_traces:
+            raise RPCRequestError(
+                f"`TransactionReceipt.{fn.__name__}` requires the `debug_traceTransaction` RPC"
+                " endpoint, but the node client does not support it or has not made it available."
+            )
         if self._trace_exc is not None:
             raise self._trace_exc
         return fn(self)
@@ -323,6 +328,10 @@ def wait(self, required_confs: int) -> None:
     def _raise_if_reverted(self, exc: Any) -> None:
         if self.status or CONFIG.mode == "console":
             return
+        if not web3.supports_traces:
+            # if traces are not available, do not attempt to determine the revert reason
+            raise exc
+
         if self._revert_msg is None:
             # no revert message and unable to check dev string - have to get trace
             self._expand_trace()
@@ -479,7 +488,8 @@ def _set_from_receipt(self, receipt: Dict) -> None:
     def _confirm_output(self) -> str:
         status = ""
         if not self.status:
-            status = f"({color('bright red')}{self.revert_msg or 'reverted'}{color}) "
+            revert_msg = self.revert_msg if web3.supports_traces else None
+            status = f"({color('bright red')}{revert_msg or 'reverted'}{color}) "
         result = (
             f"  {self._full_name()} confirmed {status}- "
             f"Block: {color('bright blue')}{self.block_number}{color}   "

brownie/network/web3.py

@@ -33,6 +33,7 @@ def __init__(self) -> None:
         self._genesis_hash: Optional[str] = None
         self._chain_uri: Optional[str] = None
         self._custom_middleware: Set = set()
+        self._supports_traces = None
 
     def connect(self, uri: str, timeout: int = 30) -> None:
         """Connects to a provider"""
@@ -89,12 +90,27 @@ def disconnect(self) -> None:
             self.provider = None
             self._genesis_hash = None
             self._chain_uri = None
+            self._supports_traces = None
 
     def isConnected(self) -> bool:
         if not self.provider:
             return False
         return super().isConnected()
 
+    @property
+    def supports_traces(self) -> bool:
+        if not self.provider:
+            return False
+
+        # Send a malformed request to `debug_traceTransaction`. If the error code
+        # returned is -32601 "endpoint does not exist/is not available" we know
+        # traces are not possible. Any other error code means the endpoint is open.
+        if self._supports_traces is None:
+            response = self.provider.make_request("debug_traceTransaction", [])
+            self._supports_traces = bool(response["error"]["code"] != -32601)
+
+        return self._supports_traces
+
     @property
     def _mainnet(self) -> _Web3:
         # a web3 instance connected to the mainnet

docs/api-network.rst

@@ -2568,6 +2568,16 @@ Web3 Attributes
         >>> web3.genesis_hash
         '41941023680923e0fe4d74a34bdac8141f2540e3ae90623718e47d66d1ca4a2d'
 
+.. py:classmethod:: Web3.supports_traces
+
+    Boolean indicating if the currently connected node client supports the `debug_traceTransaction <https://github.com/ethereum/go-ethereum/wiki/Management-APIs#user-content-debug_tracetransaction>`_ RPC endpoint.
+
+    .. code-block:: python
+
+        >>> web3.supports_traces
+        True
+
+
 Web3 Internals
 **************
 

tests/network/test_web3.py

@@ -100,3 +100,26 @@ def test_rinkeby(web3, network):
 
     # this should work because we automatically add the POA middleware
     web3.eth.getBlock("latest")
+
+
+def test_supports_traces_development(web3, devnetwork):
+    # development should return true
+    assert web3.supports_traces
+
+
+def test_supports_traces_not_connected(web3, network):
+    # should return false when disconnected
+    assert not web3.supports_traces
+
+
+def test_supports_traces_infura(web3, network):
+    # ropsten should return false (infura, geth)
+    network.connect("ropsten")
+    assert not web3.supports_traces
+
+
+def test_supports_traces_kovan(web3, network):
+    # kovan should return false (infura, parity)
+    network.connect("kovan")
+
+    assert not web3.supports_traces

tests/network/transaction/test_trace.py

@@ -6,6 +6,7 @@
 import pytest
 
 from brownie import Contract
+from brownie.exceptions import RPCRequestError
 from brownie.network.transaction import TransactionReceipt
 from brownie.project import build
 
@@ -248,3 +249,16 @@ def test_contractabi(ExternalCallTester, accounts, tester, ext_tester):
     del ExternalCallTester[0]
     ext_tester = Contract.from_abi("ExternalTesterABI", ext_tester.address, ext_tester.abi)
     tx.call_trace()
+
+
+def test_traces_not_supported(network, chain):
+    network.connect("ropsten")
+
+    tx = chain.get_transaction("0xfd9f98a245d3cff68dd67546fa7e89009a291101f045f81eb9afd14abcbdc6aa")
+
+    # the confirmation output should work even without traces
+    tx._confirm_output()
+
+    # querying the revert message should raise
+    with pytest.raises(RPCRequestError):
+        tx.revert_msg