eth/client: raise an error if a contract interaction reverts (#186)

lib/eth/client.rb

@@ -37,6 +37,9 @@ class Client
     # The default gas limit for the transaction, defaults to {Tx::DEFAULT_GAS_LIMIT}.
     attr_accessor :gas_limit
 
+    # A custom error type if a contract interaction fails.
+    class ContractExecutionError < StandardError; end
+
     # Creates a new RPC-Client, either by providing an HTTP/S host or
     # an IPC path. Supports basic authentication with username and password.
     #
@@ -345,9 +348,15 @@ def transact(contract, function, *args, **kwargs)
     #
     # See {#transact} for params and overloads.
     #
+    # @raise [Client::ContractExecutionError] if the execution fails.
     # @return [Object] returns the result of the transaction.
     def transact_and_wait(contract, function, *args, **kwargs)
-      wait_for_tx(transact(contract, function, *args, **kwargs))
+      begin
+        hash = wait_for_tx(transact(contract, function, *args, **kwargs))
+        return hash if tx_succeeded? hash
+      rescue IOError => e
+        raise ContractExecutionError, e
+      end
     end
 
     # Provides an interface to call `isValidSignature` as per EIP-1271 on a given

spec/eth/client_spec.rb

@@ -301,6 +301,16 @@
       expect(geth_dev_http.tx_succeeded? hash).to be_truthy
     end
 
+    it "raises if a transaction fails" do
+      addr = geth_dev_http.deploy_and_wait(contract)
+      hash = geth_dev_http.transact_and_wait(contract, "set", 42, address: addr)
+      expect(geth_dev_http.tx_mined? hash).to be_truthy
+      expect(geth_dev_http.tx_succeeded? hash).to be_truthy
+      expect {
+        hash = geth_dev_http.transact_and_wait(contract, "set", 138, address: addr)
+      }.to raise_error(Client::ContractExecutionError, "execution reverted")
+    end
+
     context "when nonce manually set" do
       let(:contract_address) { geth_dev_http.deploy_and_wait(contract) }
 

spec/eth/solidity_spec.rb

@@ -14,7 +14,7 @@
     result = solc.compile contract
     expect(result.keys).to eq ["Dummy"]
     expect(result["Dummy"]["abi"]).to eq JSON.parse '[{"inputs":[],"name":"get","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"x","type":"uint256"}],"name":"set","outputs":[],"stateMutability":"nonpayable","type":"function"}]'
-    expect(result["Dummy"]["bin"]).to start_with "6080604052348015600f57600080fd5b5060"
+    expect(result["Dummy"]["bin"]).to start_with "608060405234801561001057600080fd5b50"
   end
 
   it "compiles the greeter contract" do

spec/fixtures/contracts/dummy.sol

@@ -5,6 +5,7 @@ pragma solidity ^0.8;
 contract Dummy {
   uint number;
   function set(uint x) public {
+    require(x < 137);
     number = x;
   }