db2/BigTableEthRaw: fallback for unsupported method

backend/pkg/commons/db2/client.go

@@ -22,6 +22,7 @@ import (
 var ttl = 2 * time.Second
 
 var ErrNotFoundInCache = fmt.Errorf("cannot find hash in cache")
+var ErrMethodNotSupported = fmt.Errorf("methode not supported")
 
 type EthClient interface {
 	ethereum.ChainReader
@@ -52,6 +53,7 @@ func (r WithFallback) RoundTrip(request *http.Request) (*http.Response, error) {
 	var e1 *json.SyntaxError
 	if !errors.As(err, &e1) &&
 		!errors.Is(err, ErrNotFoundInCache) &&
+		!errors.Is(err, ErrMethodNotSupported) &&
 		!errors.Is(err, store.ErrNotFound) {
 		return nil, err
 	}
@@ -169,6 +171,8 @@ func (r *BigTableEthRaw) handle(ctx context.Context, message *jsonrpcMessage) (*
 		if err != nil {
 			return nil, err
 		}
+	default:
+		return nil, ErrMethodNotSupported
 	}
 	var resp jsonrpcMessage
 	_ = json.Unmarshal(respBody, &resp)

backend/pkg/commons/db2/client_test.go

@@ -180,6 +180,14 @@ func TestBigTableClientWithFallback(t *testing.T) {
 			}
 			ethClient := ethclient.NewClient(rpcClient)
 
+			balance, err := ethClient.BalanceAt(context.Background(), common.Address{}, big.NewInt(tt.block.BlockNumber))
+			if err != nil {
+				t.Fatal(err)
+			}
+			if balance == nil {
+				t.Errorf("empty balance")
+			}
+
 			block, err := ethClient.BlockByNumber(context.Background(), big.NewInt(tt.block.BlockNumber))
 			if err != nil {
 				t.Fatalf("BlockByNumber() error = %v", err)