Return notFound error if response is null

eth/block.go

@@ -1,6 +1,7 @@
 package eth
 
 import (
+	"bytes"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -23,6 +24,8 @@ func (e *Eth) getBlock(method string, args ...interface{}) (*types.Block, error)
 		return nil, err
 	} else if len(raw) == 0 {
 		return nil, ethereum.NotFound
+	} else if bytes.Equal([]byte(raw), []byte("null")) {
+		return nil, ethereum.NotFound
 	}
 
 	// Decode header and transactions.
@@ -35,7 +38,7 @@ func (e *Eth) getBlock(method string, args ...interface{}) (*types.Block, error)
 		return nil, err
 	}
 	if head == nil {
-		return nil, errors.New("nil header")
+		return nil, errors.New("json.Unmarshal header failed")
 	}
 	if head.UncleHash == types.EmptyUncleHash && len(body.UncleHashes) > 0 {
 		return nil, fmt.Errorf("server returned non-empty uncle list but block header indicates no uncles")

eth/block_test.go

@@ -0,0 +1,49 @@
+package eth
+
+import (
+	"fmt"
+	"math/big"
+	"testing"
+	"time"
+
+	"github.com/chenzhijie/go-web3/rpc"
+)
+
+func TestGetBlockByNumber(t *testing.T) {
+	c, err := rpc.NewClient("https://rpc.flashbots.net", "http://127.0.0.1:7890")
+	if err != nil {
+		t.Fatal(err)
+	}
+	eth := NewEth(c)
+	blockNumber, err := eth.GetBlockNumber()
+	if err != nil {
+		t.Fatal(err)
+	}
+	block, err := eth.GetBlocByNumber(big.NewInt(int64(blockNumber)), true)
+	if err != nil {
+		t.Fatal(err)
+	}
+	fmt.Printf("block hash %s has %v txs\n", block.Hash(), len(block.Transactions()))
+}
+
+func TestPollBlock(t *testing.T) {
+	c, err := rpc.NewClient("https://rpc.flashbots.net", "http://127.0.0.1:7890")
+	if err != nil {
+		t.Fatal(err)
+	}
+	eth := NewEth(c)
+	for {
+		blockNumber, err := eth.GetBlockNumber()
+		if err != nil {
+			t.Fatal(err)
+		}
+		fmt.Printf("get block %v\n", blockNumber)
+		block, err := eth.GetBlocByNumber(big.NewInt(int64(blockNumber)), true)
+		if err != nil {
+			t.Fatal(err)
+		}
+		fmt.Printf("block hash %s has %v txs\n", block.Hash(), len(block.Transactions()))
+		time.Sleep(time.Duration(5) * time.Second)
+	}
+
+}