accounts/abi: events can't be overloaded

accounts/abi/abi.go

@@ -187,8 +187,7 @@ func (abi *ABI) UnmarshalJSON(data []byte) error {
 			name := overloadedName(field.Name, func(s string) bool { _, ok := abi.Events[s]; return ok })
 			abi.Events[name] = NewEvent(name, field.Name, field.Anonymous, field.Inputs)
 		case "error":
-			name := overloadedName(field.Name, func(s string) bool { _, ok := abi.Errors[s]; return ok })
-			abi.Errors[name] = NewError(name, field.Name, field.Inputs)
+			abi.Errors[field.Name] = NewError(field.Name, field.Inputs)
 		default:
 			return fmt.Errorf("abi: could not recognize type %v of field %v", field.Type, field.Name)
 		}

accounts/abi/bind/bind_test.go

@@ -1862,15 +1862,18 @@ var bindTests = []struct {
 		`
 		pragma solidity >0.8.4;
 	
-		contract Test {
+		contract NewErrors {
 			error MyError(uint256);
 			error MyError1(uint256);
 			error MyError2(uint256, uint256);
 			error MyError3(uint256 a, uint256 b, uint256 c);
+			function Error() public pure {
+				revert MyError3(1,2,3);
+			}
 		}
 	   `,
-		[]string{"0x6080604052348015600f57600080fd5b50603f80601d6000396000f3fe6080604052600080fdfea2646970667358221220313fc94775b67962460298a5e968a46aed3683e1162a713923677e23373efa6364736f6c63430008060033"},
-		[]string{`[{"inputs":[{"internalType":"uint256","name":"","type":"uint256"}],"name":"MyError","type":"error"},{"inputs":[{"internalType":"uint256","name":"","type":"uint256"}],"name":"MyError1","type":"error"},{"inputs":[{"internalType":"uint256","name":"","type":"uint256"},{"internalType":"uint256","name":"","type":"uint256"}],"name":"MyError2","type":"error"},{"inputs":[{"internalType":"uint256","name":"a","type":"uint256"},{"internalType":"uint256","name":"b","type":"uint256"},{"internalType":"uint256","name":"c","type":"uint256"}],"name":"MyError3","type":"error"}]`},
+		[]string{"0x6080604052348015600f57600080fd5b5060998061001e6000396000f3fe6080604052348015600f57600080fd5b506004361060285760003560e01c8063726c638214602d575b600080fd5b60336035565b005b60405163024876cd60e61b815260016004820152600260248201526003604482015260640160405180910390fdfea264697066735822122093f786a1bc60216540cd999fbb4a6109e0fef20abcff6e9107fb2817ca968f3c64736f6c63430008070033"},
+		[]string{`[{"inputs":[{"internalType":"uint256","name":"","type":"uint256"}],"name":"MyError","type":"error"},{"inputs":[{"internalType":"uint256","name":"","type":"uint256"}],"name":"MyError1","type":"error"},{"inputs":[{"internalType":"uint256","name":"","type":"uint256"},{"internalType":"uint256","name":"","type":"uint256"}],"name":"MyError2","type":"error"},{"inputs":[{"internalType":"uint256","name":"a","type":"uint256"},{"internalType":"uint256","name":"b","type":"uint256"},{"internalType":"uint256","name":"c","type":"uint256"}],"name":"MyError3","type":"error"},{"inputs":[],"name":"Error","outputs":[],"stateMutability":"pure","type":"function"}]`},
 		`
 			"math/big"
 	
@@ -1888,7 +1891,7 @@ var bindTests = []struct {
 			)
 			defer sim.Close()
 	
-			_, tx, _, err := DeployNewErrors(user, sim)
+			_, tx, contract, err := DeployNewErrors(user, sim)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -1897,6 +1900,11 @@ var bindTests = []struct {
 			if err != nil {
 				t.Error(err)
 			}
+			if err := contract.Error(new(bind.CallOpts)); err == nil {
+				t.Fatalf("expected contract to throw error")
+			}
+			// TODO (MariusVanDerWijden unpack error using abigen
+			// once that is implemented
 	   `,
 		nil,
 		nil,

accounts/abi/error.go

@@ -17,6 +17,8 @@
 package abi
 
 import (
+	"bytes"
+	"errors"
 	"fmt"
 	"strings"
 
@@ -25,11 +27,9 @@ import (
 )
 
 type Error struct {
-	Name string
-	// RawName might be overloaded
-	RawName string
-	Inputs  Arguments
-	str     string
+	Name   string
+	Inputs Arguments
+	str    string
 	// Sig contains the string signature according to the ABI spec.
 	// e.g.	 event foo(uint32 a, int b) = "foo(uint32,int256)"
 	// Please note that "int" is substitute for its canonical representation "int256"
@@ -39,7 +39,7 @@ type Error struct {
 	ID common.Hash
 }
 
-func NewError(name, rawName string, inputs Arguments) Error {
+func NewError(name string, inputs Arguments) Error {
 	// sanitize inputs to remove inputs without names
 	// and precompute string and sig representation.
 	names := make([]string, len(inputs))
@@ -63,20 +63,29 @@ func NewError(name, rawName string, inputs Arguments) Error {
 		types[i] = input.Type.String()
 	}
 
-	str := fmt.Sprintf("event %v(%v)", rawName, strings.Join(names, ", "))
-	sig := fmt.Sprintf("%v(%v)", rawName, strings.Join(types, ","))
+	str := fmt.Sprintf("error %v(%v)", name, strings.Join(names, ", "))
+	sig := fmt.Sprintf("%v(%v)", name, strings.Join(types, ","))
 	id := common.BytesToHash(crypto.Keccak256([]byte(sig)))
 
 	return Error{
-		Name:    name,
-		RawName: rawName,
-		Inputs:  inputs,
-		str:     str,
-		Sig:     sig,
-		ID:      id,
+		Name:   name,
+		Inputs: inputs,
+		str:    str,
+		Sig:    sig,
+		ID:     id,
 	}
 }
 
-func (err *Error) String() string {
-	return err.str
+func (e *Error) String() string {
+	return e.str
+}
+
+func (e *Error) Unpack(data []byte) (interface{}, error) {
+	if len(data) < 4 {
+		return "", errors.New("invalid data for unpacking")
+	}
+	if !bytes.Equal(data[:4], e.ID[:4]) {
+		return "", errors.New("invalid data for unpacking")
+	}
+	return e.Inputs.Unpack(data[4:])
 }