graphql: customize error response

Signed-off-by: jsvisa <delweng@gmail.com>

graphql/errors.go

@@ -0,0 +1,54 @@
+// Copyright 2023 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package graphql provides a GraphQL interface to Ethereum node data.
+package graphql
+
+import (
+	"errors"
+	"fmt"
+)
+
+var (
+	errBlockInvariant    = errors.New("block objects must be instantiated with at least one of num or hash")
+	errInvalidBlockRange = errors.New("invalid from and to block combination: from > to")
+)
+
+type graphQLError struct {
+	Code    string `json:"code"`
+	Message string `json:"message"`
+}
+
+// Error implements the github.com/graph-gophers/graphql-go.ResolverError interface.
+func (e *graphQLError) Error() string {
+	return fmt.Sprintf("error [%s]: %s", e.Code, e.Message)
+}
+
+// Extensions implements the github.com/graph-gophers/graphql-go.ResolverError interface.
+func (e *graphQLError) Extensions() map[string]interface{} {
+	return map[string]interface{}{
+		"code":    e.Code,
+		"message": e.Message,
+	}
+}
+
+// asGraphQLError wraps an error into graphQLError
+func asGraphQLError(err error) error {
+	if err == nil {
+		return nil
+	}
+	return &graphQLError{Code: "-32602", Message: err.Error()}
+}

graphql/graphql.go

@@ -40,11 +40,6 @@ import (
 	"github.com/ethereum/go-ethereum/rpc"
 )
 
-var (
-	errBlockInvariant    = errors.New("block objects must be instantiated with at least one of num or hash")
-	errInvalidBlockRange = errors.New("invalid from and to block combination: from > to")
-)
-
 type Long int64
 
 // ImplementsGraphQLType returns true if Long implements the provided GraphQL type.