jsonrpc error check (#136)

* jsonrpc error check

* add ellipsis and length

* rename vars

ethrpc/ethrpc.go

@@ -11,6 +11,7 @@ import (
 	"net/http"
 	"sync/atomic"
 
+	"github.com/0xsequence/ethkit/ethrpc/jsonrpc"
 	"github.com/0xsequence/ethkit/go-ethereum"
 	"github.com/0xsequence/ethkit/go-ethereum/accounts/abi/bind"
 	"github.com/0xsequence/ethkit/go-ethereum/common"
@@ -109,14 +110,19 @@ func (p *Provider) Do(ctx context.Context, calls ...Call) ([]byte, error) {
 
 	body, err := io.ReadAll(res.Body)
 	if err != nil {
-		return nil, superr.Wrap(ErrRequestFail, fmt.Errorf("failed to read resposne body: %w", err))
+		return nil, superr.Wrap(ErrRequestFail, fmt.Errorf("failed to read response body: %w", err))
 	}
 
 	if (res.StatusCode < 200 || res.StatusCode > 299) && res.StatusCode != 401 {
+		msg := jsonrpc.Message{}
+		if err := json.Unmarshal(body, &msg); err == nil && msg.Error != nil {
+			return body, superr.Wrap(ErrRequestFail, msg.Error)
+		}
+		details := any(body)
 		if len(body) > 100 {
-			body = body[:100]
+			details = fmt.Sprintf("%s … (%d bytes)", body[:100], len(body))
 		}
-		return body, superr.Wrap(ErrRequestFail, fmt.Errorf("non-200 response with status code: %d with body '%s'", res.StatusCode, body))
+		return body, superr.Wrap(ErrRequestFail, fmt.Errorf("non-200 response with status code: %d with body '%s'", res.StatusCode, details))
 	}
 
 	if err := json.Unmarshal(body, &batch); err != nil {