From a0685a71f31c14f414c01cb5c7c91170fd0e84be Mon Sep 17 00:00:00 2001
From: Lee Bousfield <ljbousfield@gmail.com>
Date: Thu, 1 Feb 2024 14:25:55 -0700
Subject: [PATCH] Parse ABI errors in abi/bind

---
 accounts/abi/bind/base.go | 49 ++++++++++++++++++++++++++++++++++++---
 accounts/abi/error.go     |  6 ++---
 2 files changed, 49 insertions(+), 6 deletions(-)

diff --git a/accounts/abi/bind/base.go b/accounts/abi/bind/base.go
index 1c87b69d52..8f620add38 100644
--- a/accounts/abi/bind/base.go
+++ b/accounts/abi/bind/base.go
@@ -30,6 +30,7 @@ import (
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/rpc"
 )
 
 const basefeeWiggleMultiplier = 2
@@ -150,6 +151,48 @@ func DeployContract(opts *TransactOpts, abi abi.ABI, bytecode []byte, backend Co
 	return c.address, tx, c, nil
 }
 
+// parseError takes in an RPC error and attempts to parse any "execution reverted"
+// data as an ABI error, returning an improved error if possible.
+func (c *BoundContract) parseError(originalError error) error {
+	var dataErr rpc.DataError
+	if !errors.As(originalError, &dataErr) {
+		return originalError
+	}
+	dataString, ok := dataErr.ErrorData().(string)
+	if !ok {
+		return originalError
+	}
+	data := common.FromHex(dataString)
+	if len(data) < 4 {
+		return originalError
+	}
+	errAbi, _ := c.abi.ErrorByID([4]byte(data[:4]))
+	if errAbi == nil {
+		return originalError
+	}
+	vals, decodingErr := errAbi.Unpack(data)
+	if decodingErr != nil {
+		return fmt.Errorf("%w: failed to decode error as %v: %w", originalError, errAbi.Name, decodingErr)
+	}
+	for i, val := range vals {
+		bytes, ok := val.([32]byte)
+		if ok {
+			vals[i] = common.Hash(bytes)
+		}
+	}
+	fmtStr := "%w: %v("
+	for i := range vals {
+		if i > 0 {
+			fmtStr += ", "
+		}
+		fmtStr += "%v"
+	}
+	fmtStr += ")"
+	fmtArgs := []any{originalError, errAbi.Name}
+	fmtArgs = append(fmtArgs, vals...)
+	return fmt.Errorf(fmtStr, fmtArgs...)
+}
+
 // Call invokes the (constant) contract method with params as input values and
 // sets the output to result. The result type might be a single field for simple
 // returns, a slice of interfaces for anonymous returns and a struct for named
@@ -180,7 +223,7 @@ func (c *BoundContract) Call(opts *CallOpts, results *[]interface{}, method stri
 		}
 		output, err = pb.PendingCallContract(ctx, msg)
 		if err != nil {
-			return err
+			return c.parseError(err)
 		}
 		if len(output) == 0 {
 			// Make sure we have a contract to operate on, and bail out otherwise.
@@ -193,7 +236,7 @@ func (c *BoundContract) Call(opts *CallOpts, results *[]interface{}, method stri
 	} else {
 		output, err = c.caller.CallContract(ctx, msg, opts.BlockNumber)
 		if err != nil {
-			return err
+			return c.parseError(err)
 		}
 		if len(output) == 0 {
 			// Make sure we have a contract to operate on, and bail out otherwise.
@@ -357,7 +400,7 @@ func (c *BoundContract) estimateGasLimit(opts *TransactOpts, contract *common.Ad
 	}
 	gasLimit, err := c.transactor.EstimateGas(ensureContext(opts.Context), msg)
 	if err != nil {
-		return 0, err
+		return 0, c.parseError(err)
 	}
 	// Arbitrum: adjust the estimate
 	adjustedLimit := gasLimit * (10000 + opts.GasMargin) / 10000
diff --git a/accounts/abi/error.go b/accounts/abi/error.go
index 218a22f1e4..6cdef70024 100644
--- a/accounts/abi/error.go
+++ b/accounts/abi/error.go
@@ -82,12 +82,12 @@ func (e Error) String() string {
 	return e.str
 }
 
-func (e *Error) Unpack(data []byte) (interface{}, error) {
+func (e *Error) Unpack(data []byte) ([]interface{}, error) {
 	if len(data) < 4 {
-		return "", errors.New("invalid data for unpacking")
+		return nil, errors.New("invalid data for unpacking")
 	}
 	if !bytes.Equal(data[:4], e.ID[:4]) {
-		return "", errors.New("invalid data for unpacking")
+		return nil, errors.New("invalid data for unpacking")
 	}
 	return e.Inputs.Unpack(data[4:])
 }