Handle custom errors when estimating gas

ethers/contracts/gas.nim

@@ -5,6 +5,7 @@ import ../signer
 import ./contract
 import ./contractcall
 import ./transactions
+import ./errors
 import ./syntax
 
 type ContractGasEstimations[C] = distinct C
@@ -42,4 +43,4 @@ func createGasEstimationCall*(procedure: NimNode): NimNode =
   result.addAsyncPragma()
   result.addUsedPragma()
   result.addEstimateCall()
-
+  result.addErrorHandling()

testmodule/testCustomErrors.nim

@@ -97,7 +97,7 @@ suite "Contract custom errors":
     expect ErrorWithArguments:
       await contract.revertsMultipleErrors(simple = false)
 
-  test "handles gas estimation errors":
+  test "handles gas estimation errors when calling a contract function":
     proc revertsTransaction(contract: TestCustomErrors)
       {.contract, errors:[ErrorWithArguments].}
 
@@ -109,6 +109,18 @@ suite "Contract custom errors":
       check error.arguments.one == 1.u256
       check error.arguments.two == true
 
+  test "handles errors when only doing gas estimation":
+    proc revertsTransaction(contract: TestCustomErrors)
+      {.contract, errors:[ErrorWithArguments], used.}
+
+    let contract = contract.connect(provider.getSigner())
+    try:
+      discard await contract.estimateGas.revertsTransaction()
+      fail()
+    except ErrorWithArguments as error:
+      check error.arguments.one == 1.u256
+      check error.arguments.two == true
+
   test "handles transaction submission errors":
     proc revertsTransaction(contract: TestCustomErrors)
       {.contract, errors:[ErrorWithArguments].}